RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 1 OF 39
ADNOC GAS
PIPING DESIGN BASIS
COMPANY Contract No.
4700022871
JV TJN RUWAIS Contract No
215122C
Document Class
Class 1
Document Category (for Class 1)
Category 2
OPERATING CENTER Contract No.
OPERATING CENTER Doc Ref.
1
IFC – Issued for Construction
19-Mar-2025
M.Houbre
0C
ICR – Issued for Client Review
21-Fev-2025
M. Houbre
0B
ICR – Issued for Client Review
08-Oct-2024
M. Houbre
0A
ICR – Issued for Client Review
13-Aug-2024
M. Houbre
0
ICR – Issued for Client Review
21-Jun-2024
S. Fagot
V. Mathe T. Nikata A. Sequeira
V. Mathe T. Nikata A. Sequeira
V. Mathe T. Nikata A. Sequeira
V. Mathe T. Nikata A. Sequeira
V. Mathe T. Nikata A. Sequeira
S. Deilles K. Fujii
S. Deilles K. Fujii
S. Deilles K. Fujii
S. Deilles K. Fujii
S. Deilles K. Fujii
Rev.
Revision Purpose
Date
Prepared by
Checked by
Approved by
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 2 OF 39
Table of Contents
Contents
Page
1.0
INTRODUCTION … 5
1.1 1.2 1.3 1.4
SCOPE OF THE DOCUMENT … 5 HOLDS LIST … 5 REFERENCES … 6 DEFINITIONS AND ABBREVIATIONS … 7
2.0
3.0
4.0
5.0
6.0
7.0
UNITS … 8
RESPONSIBILITIES … 8
GENERAL … 8
PIPING STRESS CONSIDERATION AND COORDINATION … 8
CRITICAL PROCESS/ SYSTEMS CONSIDERATION … 9
PIPING ECONOMICS AND ERGONOMICS … 9
7.1 7.2 7.3
ECONOMICS … 9 ERGONOMICS / ACCESSIBILITY … 10 SAFETY … 10
8.0
GENERAL PIPING DESIGN CONSIDERATIONS … 10
8.1 8.2 8.3 8.4 8.5
UNDERGROUND PIPING … 13 CLOSED DRAIN PIPING… 14 SMALL BORE PIPING … 14 STRESS CONSIDERATION AND SUPPORTING … 15 SPECTACLE BLIND, SPADE AND SPACER … 15
9.0
VALVES AND VALVE ACCESS … 16
9.1 9.2 9.3 9.4 9.5 9.6 9.7
GENERAL … 16 CHECK VALVES … 17 RELIEF VALVES … 17 GLOBE VALVES … 17 BUTTERFLY VALVES … 17 VENTS, DRAINS AND SAMPLE CONNECTIONS … 18 SAMPLE POINTS … 18
10.0
UTILITY SERVICES … 18
10.1 10.2
GENERAL … 18 WATER FOR GENERAL PURPOSES … 18
11.0
INSTRUMENTATION PIPING … 19
11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8 11.9
CONTROL VALVES … 19 SAFETY VALVES … 19 LEVEL INSTRUMENTS … 20 TEMPERATURE INSTRUMENTS … 20 PRESSURE INSTRUMENTS … 20 SAMPLE STATIONS … 20 FLOW METER PIPING … 20 ORIFICE FLANGES AND ORIFICE METER RUNS … 20 ORIFICE RUNS … 20
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 3 OF 39
11.10
ORIFICE TAP ORIENTATION … 21
12.0
DESIGN OF PIPING AT PIPE RACK AND EQUIPMENT TYPES … 21
12.1 PIPE RACKS … 21 12.2 PIPE TRACKS OR SLEEPERS … 23 12.3 PUMPS … 23 12.4 COMPRESSORS … 24 12.5 TOWERS AND COLUMNS … 25 12.6 DRUMS … 26 12.7 HEAT EXCHANGERS … 26 12.8 AIR COOLERS … 27 12.9 FILTERS … 28 STORAGE TANKS … 28 12.10 12.11 WALL THICKNESS DISCREPANCY BETWEEN EQUIPMENT BUTT-WELDED NOZZLES AND PIPING … 29 PACKAGED EQUIPMENT PIPING … 29 12.12 PIPELINE PIG LAUNCHER / RECEIVER … 29 12.13
13.0
LOADING AND UNLOADING FACILITIES … 30
13.1 13.2 13.3
GENERAL … 30 TRUCK LOADING … 30 SHIP LOADING … 30
14.0
TIES-INS … 30
14.1 14.2 14.3 14.4
GENERAL … 30 TYPES OF TIE-IN … 31 HOT TAPS … 31 ADDITIONAL CONSIDERATIONS … 31
15.0
APPENDIX … 32
15.1 15.2 15.3 15.4 15.5 15.6 15.7 15.8
APPENDIX 1: ERGONOMICS/ ACCESSIBILITY – ERGONOMIC VALVE POSITIONING]… 32 APPENDIX 1: ERGONOMICS/ ACCESSIBILITY – ACCESSIBILITY REQUIREMENTS … 33 APPENDIX 2: TYPICAL PIPE RACK DESIGN – TYPICAL LINE ROUTING DIAGRAM (EXAMPLE) … 34 APPENDIX 2: TYPICAL PIPE RACK DESIGN – TYPICAL PIPE RACK LAYOUT ELEVATION … 35 APPENDIX 2: TYPICAL PIPE RACK DESIGN – TYPICAL PIPE RACK SPACE ALLOCATION PLAN (EXAMPLE) … 36 APPENDIX 2: TYPICAL PIPE RACK DESIGN –STANDARD PIPE SPACING GUIDE 1 … 37 APPENDIX 2: TYPICAL PIPING FOR CENTRIFUGAL PUMP SUCTIONS – FIGURE 1 … 38 APPENDIX 2: TYPICAL PIPING FOR CENTRIFUGAL PUMP SUCTIONS – FIGURE 2 … 39
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 4 OF 39
TABLE OF CHANGES COMPARED TO PREVIOUS REVISION
Paragraph
Modification description
Remarks/ Origin
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 5 OF 39
1.0
INTRODUCTION
The ADNOC Ruwais LNG Project is a two train, near net-zero electrically driven LNG facility, targeting international markets. The feed gas for the project is supplied from the Habshan Gas Processing Plant via a new export gas pipeline. The plant will have two 4.8 MTPA (nominal capacity) electric driven LNG Trains with associated LNG storage/marine export facilities and utilities.
The ADNOC Ruwais LNG Project foresees the following main components at the facility:
Figure 1 – Project Context
Onshore LNG Liquefaction facilities for 2 x 4.8 MTPA electrically driven LNG Trains (9.6MTPA total)
Common facilities including inlet receiving facilities, LNG storage, BOG handling, flare, refrigerant
storage and support buildings.
Utilities to support the facilities including import power from the national grid.
Marine facilities for LNG export and bunkering.
1.1
Scope of the Document
This document provides the Basis of Design for piping system and layout of piping as per ASME B31.3 within process, utility and offsite units in the ADNOC Ruwais LNG Project.
This document is intended to describe and define the methods of piping design principles and provide piping designers consistent approach to create a safe, operable, maintainable and constructible plant, designed in accordance with applicable relevant local regulations, codes, standards and procedures. It shall be used in addition and conjunction with RLNG-000-PI-BOD-0002 - Basis of Plant Layout document.
The specifications and codes referred to in this document shall, unless stated otherwise, be the latest approved issue at the time of project effective date. Conflicts existing between this and other project specifications shall be brought to the attention of the Piping Lead Engineer.
1.2
Holds List
HOLD
DESCRIPTION
1
2
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 6 OF 39
1.3
References
ADNOC standards and Specification(s)
AGES-SP-09-001 Piping Basis of Design
The AGES Specifications listed in the Appendix A3.1 of “AGES- SP-09-001 – Piping Basis of Design” have been removed from the list above and will be substituted with the ADNOC Ruwais LNG project documents.
International Codes and Standards
Refer to Applicable Codes and Standards ref. RLNG-000-PM-PP-2000
Project Documents
Mechanical Handling Philosophy Specification for Piping Stress Analysis General Specification for Pipe Supports Specification for Piping Material Service Classes Index Specification for Piping Material Classes
[1] RLNG-000-PI-BOD-0002 Basis of Plant Layout [2] RLNG-000-PI-PP-0004 [3] RLNG-000-PI-SP-0008 [4] RLNG-000-PI-SP-0010 [5] RLNG-000-PI-SP-1021 [6] RLNG-000-PI-SP-1022 [7] RLNG-000-ST-BOD-0002 Structural Design Basis [8] RLNG-000-HS-PP-0101 [9] RLNG-000-MT-SP-6301 [10] RLNG-000-PM-NM-0001 [11] RLNG-A00-PI-NM-0701 [12] RLNG-000-PI-NM-8000
Active Fire Protection Philosophy Specification for Pipe Fabrication and Erection JV Equipment List Piping Stress Critical Line List – Liquefaction Facilities Stress critical line list - LNG Storage Tank, BOG, Export & Bunkering
area
Piping Stress Critical Line List for Scope F2
[13] RLNG-000-PI-NM-7050 [14] RLNG-000-PM-BOD-2002 Project design basis [15] RLNG-000-PM-PP-2003 [16] RLNG-000-PM-PP-2009 [17] RLNG-000-PM-PP-2103 [18] RLNG-000-PM-PP-2501 [19] RLNG-000-MS-SP-0800 [20] RLNG-000PM-PP-2000 [21] RLNG-000-MT-SP-2201 [22] RLNG-000-PI-SP-0010 [23] RLNG-000-PI-DWG-0901 Standards for Pipe Supports Hot Collection [24] RLNG-000-PI-DWG-0950 Standards for Pipe Supports Cold Collection
Equipment and Component Numbering Procedure 3D Model Review Procedure 3D CAD Procedure Human Factor Engineering Specification Standard Details for Static Equipment Applicable Codes and Standards Specification for Thermal and Acoustic Insulation General Specification for Pipe Supports
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 7 OF 39
1.4
Definitions and Abbreviations
BDV BOG CODE COMPANY
CONSTRUCTABILITY
CONTRACTOR
DN EPC ESDV FEED HFE HP HSE LNG LQF MAH MOV MTPA NAW Non-operational valves NPS NPSH
Operational valves
P&ID PFD QRA SDV SP Items
SUBCONTRACTOR
UFD
Blowdown valve Boil Off Gas CODE is the applicable Design Code ABU DHABI NATIONAL OIL COMPANY (ADNOC) P.J.S.C. The structured and proactive process for early implementation of the most economical engineering, procurement and construction methods to enhance safety, cost, schedule, quality, risk mitigation and planning while ensuring compliance with the contractual requirements. TJN Ruwais, Joint Venture of Technip Energies France-Abu Dhabi, JGC Corporation and National Marines Dredging Company (NMDC) Nominal Diameter Engineering Procurement Construction Emergency Shutdown Valve Front End Engineering Design Human Factor Engineering High Pressure Health, Safety & Environmental Liquefied Natural Gas Liquefaction Facilities Major Accident Hazard Motor Operated Valve Mega Tonnes Per Annum Nitrogen Air Water Those valves only requiring to be operated for maintenance purposes. Nominal Pipe Size Net Positive Suction Head Those valves requiring to be operated during normal production or emergency situations. Piping and Instrumentation Diagram Process Flow Diagram Quantitative Risk Assessment Shut Down Valve Special Piping Items Any persons, firms, companies or partnerships (not being an employee of CONTRACTOR) engaged by CONTRACTOR for supplying services to CONTRACTOR for the performance of SERVICES Utility Flow Diagram
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 8 OF 39
2.0
UNITS
Unit shall be as per “Project design basis” RLNG-000-PM-BOD-2002.
3.0
RESPONSIBILITIES
The following personnel have responsibilities defined in this document:
Piping Lead Engineers Piping Designers Piping Engineers Process Engineers Civil/Structural Engineers Mechanical Engineers
4.0
GENERAL
Piping design relies heavily on distributed information by other disciplines. The minimum required information to perform quality Piping Design and layout is listed below:
Process Flow Diagrams (PFDs)
Utility Flow Diagram (UFDs)
Piping and Instrumentation Diagrams (P&IDs) Process Line List Piping Material Classes (PMC) Plot Plans Process and Mechanical Data sheets for all major equipment. Standard Piping Detailed Drawing include Assemblies and Pipe Supports. Piping Engineering Project Instructions produced by the Piping Lead Engineers indicating a specific data for the project.
Minimum safety distances standards
Stress analysis
5.0
PIPING STRESS CONSIDERATION AND COORDINATION
Stress Consideration and Coordination shall be as per Specification for Piping Stress Analysis (RLNG-000-PI- SP-0008). Certain lines of a process will be identified as the Stress Critical Lines by the Piping Stress Group. Lines included in the Critical Line list for Stress shall have priority routing. These lines shall have early involvement of Piping Stress Engineers to determine the validity of design. Sketches are made to provide preliminary stress runs to help to determine the pipe routing. Setting of stress critical piping is of great importance to all design disciplines. During the Planning Phase of the project (either “redline” or 3-D CAD environment) the Piping designer must work together with Piping Stress Engineers to do calculations on the critical lines. These lines shall be manually sketched or extracted from the CAD model showing planned support points, branch information, and overall dimensioning. The CAD isometric or manual sketch shall be used as a means to record any comments the stress engineer might have. Upon the completion of the stress work the piping designer is to route, locate any supports, guides, anchors and add any other stress requirements then lock these stress critical lines in the CAD Model. Changing these locked lines requires the Piping Area Lead, Project Piping lead and the Lead Stress Engineer to discuss and sign off on the revised stress sketch prior to the change being made.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 9 OF 39
The Stress Engineer and the Piping lead have the responsibility to inform the Civil/Structural group of loads including for future expansion, so major pipe supports, and structures and cross bracing in rack areas may be designed as early as possible. Reduction of high load areas through pipe configuration shall be an option and discussed with the Piping Lead, Piping Designer, Lead Pipe Stress Engineering, and the lead Civil/Structural Engineer. An early planning meeting shall be held by the Project Engineer to discuss the philosophy, the communication and coordination of miscellaneous supports.
When an acceptable line routing is resolved with Piping Design, Piping Stress, and possibly Process, it must be made known to all that change can only occur to these lines with the Piping Lead and Lead Stress Engineers approval. All critical lines which have had the routing resolved and agreed to shall be locked in the CAD model.
6.0
CRITICAL PROCESS/ SYSTEMS CONSIDERATION
Certain lines of a process have special process conditions which are critical to the line routing. These lines should be brought to the attention of the design team by the Process Group producing a Critical Line list for Process and Hydraulics.
Critical Process/System lines shall be routed and manually sketched or extracted from the CAD model. This information must have overall dimensions provided. The sketch shall be given to the Process/Systems group to do an evaluation of the hydraulic conditions in the lines. Some critical lines which need analysis and hydraulic check are listed below, but are not limited to:
- Pump Suction and discharge lines
- Column overhead and lines
- Cryogenic lines (in case of pocket in line routing)
- Main Compressor lines including anti surge lines (as required by vendor)
- Low pressure boil off lines
- Marine Loading lines.
- Flare systems
- Two-phase flow lines (wherever relevant)
- Lines upstream of Pressure relief devices (will be checked in regards with the 3% pressure
drop criterion)
7.0
PIPING ECONOMICS AND ERGONOMICS
7.1
Economics
An economical design is important to any project. The COMPANY is entitled to get an economical ‘fit for purpose’ project which is safe, easy to construct, maintain and operate. The supply, fabrication and installation cost of piping is one of the largest parts of the whole construction effort. Designers are responsible in managing these costs as much as anyone on the project. Each weld that can be avoided saves money (cutting, bevelling, welding, inspection, testing, etc.). Keeping designs as simple and straightforward as possible, balanced with the consideration of early and defined ergonomic requirements, will pay great dividend in the total installed cost.
Designers should understand and stay within the scope as specified in the design specifications and/or instructions. Do not exceed these requirements without proper change management being implemented.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 10 OF 39
7.2
Ergonomics / Accessibility
Human Factors, also known as ergonomics, refers to the human, environmental, organizational, and job factors that influence human performance. The consideration and application of these factors within the design of systems, is known as Human Factors Engineering (HFE). HFE as part of HSE Engineering covers occupational health, safety, efficiency, operability, and maintainability in design. HFE also covers major hazard safety, where human error in Major Accident Hazard (MAH) initiation, control, and mitigation is a key issue. Ease of operation is extremely important with the COMPANY. The easier a plant is to operate and maintain the safer the operators will be. Ergonomic designs include fitting the design to suit the plant operations and maintenance department. A few elements of good ergonomic piping design are listed below (see Appendix 1 for Ergonomic and Accessibility Standard Requirements respectively): All operational devices such as hand wheels, wrenches, indicators (instrumentation), etc., must be
easily accessible. Provide platforms and walkways if necessary.
All removable components over 23kg must be reachable by mobile crane, provided with permanent
lifting facilities or have access provided for mobile lifting device.
Valves with levers (e.g. ball valves) that are located in insulated lines often require extended stems that
will clear the lever from the insulation.
Ensure that 100mm free space is available around hand-wheels for operation. Check for davit requirements on large towers. All Ladders shall have side-step access to platforms. Ladders to the top platforms on vertical vessels and towers may be step through. The use of step through ladders in other places must be approved by the piping lead and the COMPANY.
Spectacle blinds or spades and spacers with a weight below 25kg may be installed in horizontal and vertical lines. Spectacle blinds or spades and spacers with a weight above 25kg shall preferably be installed in the horizontal lines only with mobile crane access or provided with a hinge point. Where access for removal is not possible by mobile crane provided with a hinge point, lifting lug from steel above, or provide access for a mobile lifting device.
Provide clearance for removal of flange bolts Provide clearance needed for expected bolt tensioning devices Sufficient space shall be allowed around large valves and flanges where air driven tools are required
for maintenance/adjustment purposes. If bolt tensioning equipment is to be used allow space.
Remote mount automated block valve accessories shall have space for access and maintenance at
grade or on platforms for elevated valve
7.3
Safety
Personnel protection insulation, as per the P&ID and Line List, will be applied for piping and equipment with operating temperatures above 60°C. Personnel Protection insulation will extend to 2500mm above and/or 800mm beyond any access or operating area.
8.0
GENERAL PIPING DESIGN CONSIDERATIONS
Clearances for roadways, access ways, emergency escape routes, operational areas and equipment
maintenance are defined in Appendix 1 of RLNG-000-PI-BOD-0002 - Basis of Plant Layout.
Generally, all piping ½” NPS and above should be designed and routed in the 3D model together with
equipment, structures, electric cable trays, etc. All piping should be routed to provide a simple, neat and economical layout allowing for adequate supporting and flexibility to meet seismic, thermal and dead weight loadings.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 11 OF 39
Pockets shall be avoided in lines, particularly those in cryogenic service, carrying corrosive chemicals, slurries and materials that congeal or solidify at ambient temperature. In particular, all gas process lines shall be routed to exclude liquid pockets. Exceptions to this will be where equipment connections are at the bottom, such as the main compressors at Liquefaction Facilities (LQF). Other exceptions are only permitted with the express agreement of the piping lead engineer and the process group. Lines carrying molten solids or slurries of high viscosity shall be sloped in the direction of flow into the receiving vessel, whenever possible. The slope should be as indicated or specified on the P&ID. Particular attention should be given to achieving the shortest and the most direct layout possible for lines in which gravity flow is required between items of equipment, especially when the fluid handled is subject to solidification and when available differential pressures are small. All equipment and piping should be arranged to provide the specified headroom and clearances for ease of operation, inspection and maintenance. Dismantling of equipment should be possible with minimum interference to equipment or piping, and without removing any block valves.
When routing piping with a minimum headroom clearance, particular attention shall be given to the
clearances required for the support steel, gusset plates, fireproofing and insulation. Piping shall be kept clear of manways, access openings, inspection points, hatches, and davits, areas for instrument removal, tower dropout areas, access ways, emergency escape routes, access ladders and access platforms, and maintenance areas for equipment. Piping is responsible through the first root valve of any instrument including, pressure, level and flow instruments. Piping will supply nipples and valves for orifice flanges. Instrument and Controls shall provide all valves and manifolds downstream of the first root valve.
Wherever possible, the Piping, Electrical, and Instrument and Control groups set common support levels for pipework, ducting, and electrical and instrument trays early in the planning stages of the project. These elevations agreed will be maintained whenever possible. Any valve designated with an Instrument Bubble on the P&ID shall be specified and supplied by the Instrument and Control department including control valves and automated shutdown valves. Flare sub header(s) shall be sloped with minimum 1:200 towards the main flare header while the main flare header shall be sloped to a downstream flare K-O drum with a minimum slope of 1:500 or as per specific requirement specified on the P &ID’s. Flushing connections shall be as close as possible to block valves in process lines. Flushing outlets in horizontal lines shall be at the bottom. Piping penetrating walls, floors, or platforms shall pass through a sleeve or hole with a large enough opening to account for installation of prefabricated pieces and insulation thickness (if applicable). Sealing shall be applied as necessary. Pipe penetration through fire/blast wall should be avoided. Flanges on a vertical pipe or vessel nozzle that penetrates through deck shall have a minimum of 150 mm gap or space required for hydraulic bolt tensioning whichever is higher, between the top of the kick plate and the flange bottom nut surface to allow sufficient space for a wrench and a hand. Penetrating holes in grating through platforms shall be banded on the inside of the hole and a toe-plate provided if opening exceeds outside diameter of pipe and/or insulation by more than 40mm.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 12 OF 39
Piping subject to vibration (either from mechanical equipment or process conditions) shall be reviewed by the stress engineer to determine the need for branch bracing and/or gussets on small bore (≤ 2 NPS) branch lines. In addition, for small bore piping the following table can be followed:
Location (1)
Reciprocating compressors
Centrifugal compressors/ Centrifugal pumps
Piping system subject to Process induced vibration (AIV, FIV, Slug flow, water hammer, …)
Pressure throttling devices (BDV, PSV/PRV, pressure let down station etc.,)
Small-bore connection with multiple isolation valves or cantilever mass not located closer to the branch (with pipe spool more than 150 mm or arrangement involving more than one elbow)
Bracing Requirement
All small-bore connections connected with reciprocating compressor circuit shall be provided with bracing support from parent pipe Any small-bore connections to piping within the greater of 6m or up to two pipe supports, measured along the pipe axis from the equipment nozzle All small-bore piping connections shall be provided with brace support unless specific study is conducted Any small-bore branch piping on the inlet and out piping within the greater of 6m or up to two pipe supports, measured along the pipe axis from throttling device
Brace support shall be provided
Note (1): Other applicable cases should be identified during the design stage.
For buried pipe operating at a temperature of 60°C, or below there shall be a clear distance of at least 305mm between the pipe and any electrical or instrument cables. For buried pipe with impressed cathodic protection, there shall be a clear distance of at least 1000mm between the pipe and any parallel running cables, to prevent stray-current corrosion of the armoured steel wire of those cables. Buried piping shall be designed so that the complete system can be flushed and cleaned (i.e. Dead ends should be avoided) Sumps should be at least 1500mm from ignition source including plant roads. All connections in a drip/drain network shall be liquid sealed by means of turned down elbows. (P-traps). Collection sumps/manholes/stormceptors shall be connected by means of liquid filled underground drain pipes (P-traps) to a main collection sump/vessel located close to the battery limit of the plot area. Flanges shall not be located above main roads outside unit battery limits At process vent and drains where process requirements demand a quick outlet to atmosphere double barrier isolation shall be obtained by installing two valves in series, If the effluent will flash and cause sub- zero temperatures, the distance between the two valves shall be at least 610mm and the downstream (low pressure) valve shall be of the spring loaded, self-closing type. The number of vent and drain connections with valves shall be minimised. In order to avoid a fire hazard, lubricating oil, control oil and seal oil shall not be routed in the vicinity of hot process or utility pipes. Liquid LPG/LNG piping and high-pressure liquid/gas hydrocarbon piping shall be arranged such that flame impingement on a LPG liquid inventory (e.g. A kettle type heat exchanger or column bottom) by a liquid jet from a leak source in this piping (e.g., a flange) cannot occur. Insulation shall be added to piping and equipment by type as indicated on the P&ID’s and line list. The limits of the insulation will be shown in the model and on the piping isometrics. Piping layout shall not result in tripping hazards.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 13 OF 39
8.1
Underground Piping
Underground piping should have sufficient horizontal clearance from structures and Equipment foundations to provide room for maintenance. Depth of piping burial should be determined based on the following factors:
a. Commodity being carried b. Whether flow depends on pressure or gravity c. Traffic loads d. Weight of cover loads e. Depth of frost line
Underground piping should be located above the bottom of spread footings or mat foundations or beyond
a line sloping downward at 45 degrees from the base of the foundation.
Underground piping can require room for massive thrust block for piping restraint at bend and elbow. Large
pipelines, specifically water supply or cooling lines, typically require thrust blocks. The minimum depth of the underground buried lines from top of the buried pipe shall be as below, unless otherwise approved by the COMPANY.
In Areas inaccessible to traffic
0.9 m
1.0 m
Metallic Piping No-metallic Piping
For buried pipes crossing roads (including areas accessible to traffic) inside plant areas:
-
For Metallic pipes the preferred method is to provide culverts under access roads. When determining width and height of culvert, care must be taken to allow sufficient room round the pipe work for maintenance, insulation and painting. Elevating piping on a cross-over rack / bridge is expensive and introduces unnecessary pockets in the lines. When determining width and height of culvert, care must be taken to allow sufficient room round the pipe work for maintenance, insulation and painting.
-
Buried piping shall not be used for pressurized hydrocarbon service unless approved by the
COMPANY with suitable protection methods.
- For Non-metallic pipes suitable protection methods (Culverts/inverts/casing, etc.,) shall be provided. In addition, manufacturer shall submit detail calculation in line with AWWA M45.
Insulated pipes should not be buried. Soil settlement and thermal expansion of the piping shall be taken into account in the design of underground piping. For buried pipes operating above 60°C, there shall be a clear distance of at least 600 mm between the pipe and any electrical or instrument cables. The underground piping if recommended in carbon steel construction shall be externally coated / protected against corrosion in line with RLNG-000-MT-SP-2301 - Specification for Protective Coating of Equipment, Piping & Structures For buried pipes, which have impressed current cathodic protection, there shall be a clear distance of at least 1 m between the pipe and any parallel-running cables, to prevent stray current corrosion of the steel wire armouring or those cables in line with RLNG-000-MT-SP-5001 - Specification for Cathodic Protection and Design Report. Piping shall be designed so that the complete system can be flushed and cleaned (for example “dead ends” should be avoided).
Whenever underground pipes, cable, or instrument lines cross public roads, they shall be combined together, with appropriate spacing, and pass through underground “culverts” instead of being directly buried Flange connections for the U/G drain piping system shall be eliminated. In case they are necessary, they shall be placed in a pit. This is for easy inspection in case of leakage. Valve pits with adequate maintenance and clearances shall be provided for all valves in Underground piping.
UG non-metallic piping shall have a minimum clearance from adjacent foundation of 1 meter.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 14 OF 39
8.2
Closed Drain Piping
These are defined as fully contained drains, hard piped from the systems to be drained to the collection systems before safe disposal to the environment. As a general rule, any facility containing hazardous liquids which need to be drained for operational and maintenance reasons shall be connected to a closed drain system. Additionally, backflow from high pressure to low pressure systems across common drain systems in the event of mal operation should be considered during design.
Closed Drain Drums should be located suitably at the Process Area to optimize elevation and routing of
sloping free-draining lines underground drain lines.
Closed drain drums shall be located in underground pit. The size of the pit and access shall consider operational, maintenance and inspection requirements with minimum primary stair access and secondary ladder access in line with HSE requirements. Pressure drain systems shall be closed systems. Closed drain systems shall be completely independent from the open drain system.
Drain lines shall be sloped as follows: 1:300 for main headers and 1:100 for sub headers unless indicated otherwise in P&ID. Branch lines, which are used intermittently, (such as vessel drains), shall enter drain headers from above the centre line, of the drain header to prevent liquids from standing in the branch lines. Adequate rodding points shall be provided at start of header/sub headers and all directional changes in drain lines to facilitate cleaning of the drain lines.
8.3
Small Bore Piping
Since small bore branches (≤ 2”) to large bore piping are relatively susceptible to failure, the following points shall be incorporated in piping design for avoidance of vibration induced fatigue of small-bore piping and branch connections. See RLNG-000-PI-SP-0008 - Specification for Piping Stress Analysis and RLNG- 000-PI-SP-0010 - General Specification for Pipe Supports. Minimise the number of small-bore branches to piping Small bore piping, including method of support, shall be shown in full detail, either on the isometric
drawings or on a reference document.
Branches shall not be located on removable spools unless it is impractical to do otherwise. Cooling water pipes to pumps and compressors shall have the water connection from the top of the
main pipe.
Branches shall not be located in high stress areas. The unsupported length of the branch and associated fittings should be as short as possible. The mass/weight of the assembly should be as low as possible. Avoid installation of heavy components
(e.g. Flanged valves) on the end of the connections.
Unreinforced branch connections shall not be installed immediately in the downstream of high-capacity gas reducing systems such as compressor recycle systems, high rate depressuring valves and safety relief valves.
The bracing of complex geometries of connections or branches with heavy valve or flange weights shall
be checked by a pipe stress engineer or vibration analyst.
Gussets and bracing supports shall be provided for unsupported small-bore branches having heavy
valves.
Where branches have flanged valves, branch fittings with flanged outlets shall be used wherever
possible if available in the piping material classes in order to reduce the number of welds.
Non-direct-mounted instruments should be kept as simple as possible. The length of the branch should be minimised (fitting to fitting) with isolation valves as per the latest piping classes. With only tubing or pressure instrument connected to be connected to the isolation valve.
For situations where vibration may be expected, like near compressors, connecting points to the main piping should be located at positions where vibration amplitudes are lower, such as near fixed points at pipe supports. The use of larger piping is preferred over the use of support bracing attachments to the small-bore piping for situations where increased mechanical strength is required. In addition, for small bore piping the following table can be followed:
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 15 OF 39
Location (1)
Reciprocating compressors
Centrifugal compressors/ Centrifugal pumps
Piping system subject to Process induced vibration (AIV, FIV, Slug flow, water hammer, …)
Pressure throttling devices (BDV, PSV/PRV, pressure let down station etc.,)
Small-bore connection with multiple isolation valves or cantilever mass not located closer to the branch (with pipe spool more than 150 mm or arrangement involving more than one elbow)
Bracing Requirement
All small-bore connections connected with reciprocating compressor circuit shall be provided with bracing support from parent pipe Any small-bore connections to piping within the greater of 6m or up to two pipe supports, measured along the pipe axis from the equipment nozzle All small-bore piping connections shall be provided with brace support unless specific study is conducted Any small-bore branch piping on the inlet and out piping within the greater of 6m or up to two pipe supports, measured along the pipe axis from throttling device
Brace support shall be provided
Note (1): Other applicable cases should be identified during the design stage.
8.4
Stress Consideration and Supporting
It is preferred that adequate flexibility should be built into the piping layout without the use of expansion bellows, flexible pipes, flexible connectors or expansion loops. (Storage tank piping, which may have special requirements for use of flexible pipe and bellows units due to settlement, should be reviewed on a case-by-case basis). Stress Sketches or Pipe Stress Isometrics shall be produced for all stress critical lines and shall be analysed by the Pipe Stress Engineer in accordance with RLNG-000-PI-SP-0008 - Specification for Piping Stress Analysis. To accommodate thermal expansion of pipework or equipment, the following means are preferred in the order shown: Taking advantage of the inherent flexibility of the minimum layout. Utilize a designed expansion loop. Piping shall be supported whenever possible using the Standard Pipe Supports Drawings as developed and issued by EPC Contractor for the project. In the event modifications to standard supports have to occur, the modified pipe supports becomes a Special Pipe Support and must be designed, detailed and issued by the Pipe Stress, Support or Structural Engineer as such.
Where possible small-bore piping should be routed in groups for supporting on common supports.
All Miscellaneous Supports shall be considered as early as possible.
8.5
Spectacle blind, Spade and Spacer
Spectacle blinds, spades, spacers and blind flanges shall have the same material and ASME class rating as the pipe class of the connected piping. See the RLNG-000-PI-SP-1022 - Specification for Piping Material Classes. In order to prevent icing problems, spectacle blinds shall not be installed in pipes with operating temperatures below 0°C. Spacer and blanks shall be considered instead of spectacle blinds in such cases. Piping shall be properly designed, supported and installed so that the flanges do not move when the bolting is removed for spading purposes. The piping shall be sufficiently flexible to be able to install the required isolation fittings (spades, blind plates etc.) and there shall be sufficient space to turn spectacle blinds, where provided.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 16 OF 39
Spade / Spacer & Spectacle Blind shall not be directly inserted between two isolating valves such that it difficult to remove bolting once installed. A spool piece shall be installed between two valves such that bolts can be easily removed during spading operation. Spade / Spacer & Spectacle blinds shall not be installed in conjunction with insulating gasket on one side. In case insulating gasket is required, it shall be installed on separate set of flanges Spectacle blinds or spades should be positioned in horizontal lines whenever possible. Spectacle blinds, spacers and blinds maintainability and operation to be considered accessible from deck level or permanent platform.
Closely grouped flanges with blinds are to be staggered.
Adequate space for swinging a spectacle blind, reinstalling the blind, and removal shall be considered. Flange spreader is preferred over of jackscrew to avoid corrosion issues and damage to flanges. Piping arrangement shall identify dedicated common storage space/racks for blind and spacers in the layout at every level/unit area. The blinds identification shall be legibly stamped on it, including size and ASME rating, and possible service description.
9.0
VALVES AND VALVE ACCESS
9.1
General
See Section 1.4 “Definitions and Abbreviations” above for definition of “operational” and “non-operational” valves. Valve types shall be selected in accordance with the relevant piping class and as indicated on the P&ID. Valve hand wheel, lever, and operators shall be modelled in their correct orientation along with obstruction volumes so clash detection will indicate any encroachment.
Non-operational branch block valves at headers should be located in the horizontal high point to ensure
drainage in both directions. Locating process valves in overhead pipe racks should be avoided. Other valves located in pipe racks shall be considered accessible. Valves to be used in cryogenic temperature services will be ordered with extended bonnets of sufficient length to provide an insulating gas column above the cold medium, to prevent shrinkage of the stem packing. This extended bonnet will be partly located outside the insulation and the outside temperature will ‘heat-up’ the liquid/vapor and as such protect the stem packing from freezing. Valves in liquid and/or liquid/vapour cryogenic service shall be installed with the stem oriented upwards (preferred), or with a maximum inclination of 45°deg. from the vertical. This orientation prevents the (cold) liquid to flow into the bonnet extension and make contact with the stem packing.
Cryogenic valves that are vapour trapped do not require to be installed in the cryogenic position required in paragraph above. Examples of this arrangement include instrument connections, inlets and outlets to pressure relief valves and non-operating vents.
Gate valves and ball valves in cryogenic propane, LNG and NGL services require special attention to protect the cavity of the valve. When in closed position, the liquids trapped in this cavity could vaporise when the temperature rises resulting in over-pressuring the cavity and damaging the valve. To protect gate valves and ball valves in cryogenic services valve vendors, (preferably) provide the valve with a cavity relieving seat. External cavity vent piping is not allowed. The gate valve and ball valve must be positioned such that this bleed hole depressurises to the high-pressure side of the valve. Valve bodies shall be clearly marked with cavity vent location. Cavity vent location will be marked on P&ID’s.
Normally the high-pressure side is the upstream side of the valve, but in some instances the pressure might act on the downstream side of the valve (and against the flow direction), e.g. the 2nd block valve at a control valve set, when the block valves are closed and the by-pass is operating. The high-pressure side of the valve will be indicated on the P&ID’s All operational valves should be easily accessible either from grade, permanent platforms, stairs, or ladders. See Appendix 1 - ERGONOMICS / ACCESSIBILITY – ACCESSIBILITY REQUIREMENTS.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 17 OF 39
Non-operational valves 2” NPS and smaller, including instrument isolating valves, should be accessed via a portable ladder as a minimum, provided that the bottom of hand wheel elevation is between 2100mm and 3000mm above grade or platform.
Non- Operational valves 3” NPS and larger should be accessed via grade or a fixed or portable platform. See the “Minimum Access Provisions for exceptions and other requirements” in the Appendix 1 of RLNG- 000-PI-BOD-0002 - Basis of Plant Layout document. As an alternative extension stems should be reviewed on an individual basis. Chain operators shall only be used with the approval of the Piping Lead and the COMPANY on a case-by-case basis. The use of chain operators should be avoided if possible.
When chain operators are used the following limitations shall apply:
Not permitted below 3” NPS Valve bottom of handwheel shall be 2100mm min. above grade/platform level Chains shall not obstruct access ways Chains shall be lockable. Preferred valve hand wheel elevations are as per Appendix 1 - ERGONOMICS / ACCESSIBILITY – ERGONOMIC VALVE POSTIONING. For all services, valve stems will not be orientated below the horizontal without the specific approval. Gate valves installed on each side of a relief valves will have the stem in the horizontal position. Block valves in pipe racks need no permanent access, with the exception of battery unit valves.
9.2
Check Valves
Dual plate type check valves with discs that open beyond the body shall not be installed adjacent to any item that prevents the valve from fully opening. Requirement for straight piping upstream of dual plate type check valves is to be considered. In general check valves should be installed in horizontal lines. If check valves are to be installed in vertical lines, the flow should be upwards, and the designer should ensure that the check valves specified are suitable for vertical operation and the service fluid. A drain connection shall be provided above the valve or on the cover plate. Check valves in vertical lines shall only be used with the approval of the piping lead and the COMPANY Attention should be given to bolt withdrawal requirements on one side when using wafer check valves. Piston type check valves should be installed in the horizontal unless they are spring loaded valves.
9.3
Relief Valves
Relief valves shall be installed in the vertical position, as close to the pressure source as possible, and be provided with permanent platform access. See the “Minimum Access Provisions for exceptions and other requirements” in the Appendix 1 of RLNG-000-PI-BOD-0002 - Basis of Plant Layout document.
9.4
Globe Valves
Globe valves shall be installed in such a way that they close against the pressure.
9.5
Butterfly Valves
Butterfly valves with discs that open beyond the body shall not be installed adjacent to any item that prevents the valve from fully opening. Attention should be given to bolt withdrawal requirements when using wafer butterfly valves Follow P&IDs for indication of High-Pressure sides. Butterfly valves in services where collection of dirt in the lower shaft bearing could occur shall have the stem horizontal.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 18 OF 39
9.6
Vents, Drains and Sample Connections
Piping and Instrument Diagrams shall show all process drains, vents and sample points required on piping systems and equipment. Any vent or drain with a valve must be included on the P&ID for valve numbering. Hydrostatic test vents and drains required for venting and draining systems during pressure testing are not normally shown on the P&ID. They shall be included in the CAD model and will be shown on the piping detail isometric.
Details of Vent and Drain configurations shall be provided via Standard (Assembly) drawing during the
detailed Design (EPC) Phase.
Hydrostatic vents and drains are not required for lines in cryogenic service; Low point drains will be
required. In some cases, such as connections on lines governed by pipeline design codes, the branch connection size shall be 2 NPS minimum, where this is the case it should be indicated on the P&ID.
No hydrostatic test vents and drains are required in air and nitrogen lines as these will be service tested. Drain valves shall be considered with a min. clearance of 300mm from finished concrete, floor or platform. For minimum clearances in other areas, refer to clause 11.6 of AGES-SP-09-001 (clearance is to be taken from bottom of main pipe not including drain valve).
9.7
Sample Points
All sample connections shall be arranged in accordance with P&IDs. Sample connections should preferably be installed in the side of a pipe rather than the top or bottom; they shall not be located in dead legs. However, sample pipes shall be as short as possible as and not longer than 8m.
Where practical, sample connections should be located close to drains and shall be accessible from grade
or a platform.
Direction of flow relative to a sample probe should clearly be indicated on the Isometrics.
Sample point connections shall be located at least 12 pipe diameters from the junction of two streams. They shall be at least 12 pipe diameters downstream of a pressure reducer where two phase flow can exist, or as indicated on the P&ID’s.
10.0 UTILITY SERVICES
10.1 General
Where required for maintenance and cleaning, utility stations shall be provided at grade and working levels
for elevated equipment.
Utility services at grade shall be located advantageously in unit so that required areas may be reached with a 20m hose (i.e. coverage radius of 15m). Utility stations on towers and vessels located 11m above grade will only have air service. See also section 12.1. Certain structures will need utility stations with air and nitrogen.
10.2 Water for General Purposes
Utility water branch lines shall be taken from the top of the header.
Block valves shall be provided for branch connections less than NPS < NPS 2 and shall be located both at the header and at the equipment A clear distinction shall be made between potable water (water of drinking water purity), industrial water and various kinds of cooling water.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 19 OF 39
11.0
INSTRUMENTATION PIPING
11.1 Control Valves
All Instrument control valves including ESDV, SDV, BDV, and MOV etc. should be installed with ease of removal for maintenance in a horizontal line and the actuator in a vertical position. ESD valve and adjacent block valves shall be separated by pipe spool of sufficient length. Control valves in cryogenic service shall have extended stems which may require supporting. Consultation with the supplier may be necessary to determine the requirements. The location of ESD valves, and extent of fireproofing requirements, shall be in accordance with the outcome of the HSE and QRA studies. ESD and major isolation valves are to be preferably located at grade level or shall be provided with good and safe access and be located a minimum of 15 m horizontally from the equipment protected or as defined in RLNG-000-PI-BOD-0002 - Basis of Plant Layout document. If a butterfly type control valve is installed in a line, it should be confirmed that there is adequate clearance between the valve actuator and adjacent line or the insulation. All control valves shall be easily accessible from grade or permanent access platform and conveniently located for ease of operation and full maintenance. They shall be as close as possible to the item of plant under control. They shall also be located so that the instrument department can locate any associated local indicator within view of the control valve and the by-pass valve. To minimize noise in piping downstream of high pressure drop control valves (identified by Instruments/Process during the design phase), one or more of the following shall be considered in the piping design: Avoid abrupt changes in flow direction. Use Venturi (conical) type reducers to avoid abrupt change of direction. Use straightening vanes to reduce large scale turbulence. This should be use only when required (i.e.
impossible to provide enough straight length of pipe).
Use extra heavy wall pipe and fittings to attenuate sound and vibration. Use attenuation plate at the valve. Use acoustic insulation and/or shielding around pipe and fittings to absorb or isolate sound. Use upstream & downstream straight lengths of pipe based on the valve NPS diameter. Guidelines for
the extent of straight piping will be as follows:
Duty
Upstream Straight Downstream straight
Liquid - no flashing
Liquid – flashing possible
N/A
N/A
Gas/vapor – normal duty
2 Diameters
Gas – severe duty
5 Diameters
N/A
5 Diameters
3 Diameters
7 Diameters
Such valves will be identified by Inst. /Process during the design phase of the project.
11.2
Safety valves
Safety valves in hazardous services such as flammable, toxic, noxious or corrosive materials discharging to atmosphere shall terminate at least 2.5m above any working surface or platform located within a 15m radius. Discharge tail pipes discharging up (preferred to horizontal) shall be cut off squarely and provided with a 10mm weep hole in the lowest point. Discharge tail pipes discharging horizontally, shall be cut off squarely and supplied with a 10mm weep hole.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 20 OF 39
Safety valves in non-hazardous services such as utility piping discharging to atmosphere shall terminate at least 2.5m above any working surface or platform located within a 7.5m radius. Discharge tail pipes discharging up (preferred to horizontal) shall be cut off squarely and provided with a 6mm weep hole in the lowest point. Discharge tail pipes discharging horizontally, shall be cut off squarely and supplied with a 6mm weep hole. Safety valves discharging to a flare header shall be located above the header with discharge lines self- draining to the flare header. All inlet lines to Safety valves shall be designed without pocketing and self- draining back to the source (equipment or pipe).
11.3
Level Instruments
Block valves shall be installed to facilitate venting, draining, flushing, rodding and filling of liquid for test/calibration purposes
11.4
Temperature Instruments
Thermowell locations shall have a preferred minimum of 10 pipe diameters downstream of a junction of two streams with different temperatures, or as indicated on the P&ID’s. All temperature Instrument locations shall have clearances in which the temperature element and thermowell may be withdrawn without interference. The minimum clearance above the temperature instrument should be 600mm for Skin Temp. Sensors 600mm clearance shall be provided for extraction of the sensor. Thermowell piping details shall be provided via Standard (Assembly) drawing during the detailed Design. Screwed thermowells shall not be seal welded.
11.5
Pressure Instruments
Pressure gauges shall be up stream of Thermowell connections in close proximity.
11.6
Sample Stations
The minimum branch size to the sample station shall be determined by the requirements of the sample probe. (SP item)
11.7
Flow meter Piping
Flow meters except Rota meters should be in the horizontal line. Vertical orifice runs may be used with the approval of COMPANY after confirming with the flow meter vendor.
11.8 Orifice Flanges and Orifice Meter Runs
Orifice flanges with flange tapings shall be in accordance with ASME B16.36. Material and components for instrument connections shall be determined based on the relevant piping
classes.
11.9 Orifice Runs
Orifice runs should be located in horizontal piping. Vertical orifice runs may only be used with the approval
of the COMPANY. Sufficient upstream and downstream straight length pipe shall be provided for the flow meter piping as per Vendor recommendation.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 21 OF 39
11.10 Orifice Tap Orientation
The orifice flange taps shall be oriented in such a way that suits the measurement of fluid flow passing through the pipe. For vertical piping, the taps shall point in the direction from which they are accessible. For normal applications on average size piping, the angle between the taps should be approximately 90°. For large size piping a somewhat smaller angle may be more practicable and is therefore acceptable. For horizontal pipes, the orientation should be such that the taps are self-draining on gas service or steam service and are self-venting on liquid service, but in locations where sub-zero temperatures may occur the taps for liquid service shall be self-draining. For horizontal piping, bolts shall not obstruct the vertical position of the tab on the orifice plate (upwards on gas and steam service, downwards on liquid service).
12.0 DESIGN OF PIPING AT PIPE RACK AND EQUIPMENT TYPES
Normally pipe sleeper/rack width is determined based on the present design requirements. An adequate contingency and future requirement shall be considered in design. Minimum provision on pipe sleepers/racks of 20% spare space shall be maintained during detail Engineering (60% model review for Pipe rack). This additional space should be distributed between Utility and Process levels and corresponding to each level quantity. This space may be used as contingency during EPC for unforeseen design developments during EPC. This does not include known future pipes indicated in P&ID / project documentation.
12.1
Pipe racks
See Appendix 2 for Typical Pipe Rack Design A line routing diagram may be most helpful in starting the rack piping design effort. This diagram will show approximations of heavily loaded areas. If a pipe rack forms part of a structure or it is located next to a structure and if possible, the stanchions of the pipe rack should line up with the columns of the structure, to make optimal use of space for incoming and outgoing pipes. Equipment which is a potential source of fire shall not be located under pipe racks. For layout requirements see RLNG-000-PI-BOD-0002 Basis of Plant Layout document.
Wherever possible, all piping should be carried side by side on overhead pipe supports at a common elevation for bottom of piping/pipe support and should be grouped by size for economical support. Sufficient clearance should be allowed between lines to permit ready access for removal and/or repair. In no instances should there be less than 25mm between a pipe and the outside of the largest flange or fitting of the adjacent pipe or nearest obstruction. The number of flanged joints in pipe racks needs to be minimised. If flanges are used in a pipe rack enough clearance must be allowed for bolt removal. Insulation thickness and movement due to thermal expansion or contraction must be considered when determining pipe spacing and elevation. Any potential movement due to seismic loads should also be considered if the seismic conditions are design criteria. Specific pipe rack elevations should be established, and where possible North/South pipework should be run at a different elevation to East/West pipework. At every change of direction the piping should change elevation but care should be taken to ensure pockets are avoided. Utility headers should generally be placed above the process lines in multi-tier pipe racks, reserving the top layer of rack for cable tray routing. Special consideration should be given to piping 30” NPS and larger which may require flat turns or flat expansion loops. Lines containing corrosive fluids should be run on the lowest rack level to minimize the effect of leakage onto adjacent piping, they should not be routed over cable trays
Cold and hot piping should be grouped separately with hot un-insulated lines located at a higher elevation than cold lines wherever possible and at the greatest possible distance from the edge of access ways.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 22 OF 39
Lines in pipe racks requiring expansion loops should be grouped together at the edge of the pipe rack. The loops should be routed together, between or above main pipe rack level. They should be extended to the edge of rack for support on the spandrel beams. The locating of small lines between large lines should be avoided especially when the large lines are hot. Depending on the type of pipe rack/support heavy lines should generally be located on the outside of rack. Lines that require a slope such as flare headers and drain lines should generally be located together and can be on the outside of the rack. The routing and support requirements should be established at an early stage in the design period to prevent difficulties when other process and utility piping runs have been established.
Where there is a definite requirement for future lines, they should be routed for space management and shown on relevant layout drawings and/or CAD model placing envelopes for future into the 3-D model. Space requirements for electrical and instrument cable tray should be considered when determining widths of the pipe racks. Typically, the top level of a rack would be reserved for electrical and instrument control tray routing. Space requirements for Utility (NAW) Stations should be considered to determine locations and accessibility usually being located at rack columns. The order of the utility drops at utility stations will be: N2 – Nitrogen, PA – Air and UW - Water when facing the station, from left to right. Battery Limits areas requiring unit isolation valves shall be accessed by permanent platform. Other rack block valves do not need permanent access.
Nominal pipe sizes of <2” NPS shall not be routed in Pipe racks and bridges. Swaging up to 2” NPS will be
required for pipe spans between rack bents. Branch connections in the following services shall be taken off the top of the header: Flare (Note-1) All Air (instrument and plant) Fuel gas Water lines Vapour lines with possible liquid entrainment Nitrogen
Note-1: Flat connection on flare branches shall be used with specific COMPANY approval. Minimum clearance between piping or outside insulation and piping or outside insulation or steel, etc., will
Piping shall preferably be anchored at the Battery limits.
be 100mm. Pipe To Pipe Spacing: The design shall take the following criteria into consideration for pipe spacing. See Appendix 2- STANDARD PIPE SPACING GUIDE 1& 2 Thermal insulation Wall and floor seating detail (pipe supports and guides thereon) Side movements due to expansion Linear movement at changes of direction Flange Outside diameter Where one or more pipes are running alongside each other and are guided, provision is to be made in
the spacing for these guides.
Adjacent pipe guides should be staggered to minimise pipe space requirements. Adjacent flanges should be staggered to minimise pipe space requirements. Valves and flanges should be staggered whenever possible to ease operation and reduce space. The distance between pipes shall allow for the turning of a spectacle blind, where present. Expansion loop nests shall be checked for differential expansion between the pipes at different
temperature
When Pipes and/or Flange is insulated the, insulation thickness shall be added to minimum spacing.
Drainage trenches should not be run under pipe racks.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 23 OF 39
12.2
Pipe tracks or sleepers
Piping may be routed on pipe-tracks or sleeper supports. These supports are an economic solution usually pre-cast concrete with a 50mm wide carbon steel insert load plate on the top surface. Unlike pipe racks, pipe tracks block access at low level and shall be used only in offsite areas where space is not a premium or where safety access and equipment access requirements are minimal.
Outside the plot and in tankage areas, pipes should normally be laid on pipe sleepers. There should be not
less than 1 m distance between the nearest edge of a pipe sleeper and the toe of a bund. The elevation of the pipe-tracks is set by access requirements to drains. A minimum of 300 mm clearance between underneath of lines and grade is recommended in paved areas. In offsite/unpaved areas this shall be increased to minimum 450 mm. Piping running on ground level in desert areas/outside plant area, where sand accumulation is expected shall have enough elevation (minimum 600 mm) clearances to allow for sand cleaning activities. As sand is more prone to fence accumulate against solid structures, piping support should be designed to minimize accumulations.
Requirement of expansion loops, anchor location, etc., shall be discussed in consultation with stress
engineer and structural engineers at the beginning of the pipe sleeper layout. Pipes 2” and above on sleepers shall be provided with pipe shoes to avoid external corrosion at support location due to corrosive environment.
12.3
Pumps
All planned pumps on a project shall be reviewed during the planning stage of a project with the Piping Designer, Pipe Stress Engineer, Mechanical Engineer and Process Engineer. Consideration for consistent and typical pump hook ups shall be explored at the plant layout and planning stage. The consistency and typical arrangements may reduce cost in Piping Stress Engineering and Construction.
Net Positive Suction Head (NPSH) shall be considered upon layout of pump areas by the Piping Designer to set equipment elevation of suction sources. Suctions line to pumps shall be checked by the process group to ensure the NPSH falls within the range of the pump performance curve. Piping to provide sketches as per section 7.2. Suction lines shall be designed to be as short as possible. Piping should be routed to fall continuously from the source to the pump ensuring there are no pockets where vapour or gas can collect. Only eccentric reducers (top flat) may be used for diameter changes in horizontal pipes to help eliminate pump cavitation. A drain shall be provided upstream of the reducer. Special consideration should be given to centrifugal pumps. See Appendix 3 for recommended straight diameters upstream of pump nozzles per API 686RP and ANSI/HI 9.6.6-2009.The Mechanical group shall confirm the straight length requirements for detail design development. Lines at reciprocating pumps shall be designed and supported such that pistons can be removed without disturbing piping. Piping at pumps and drivers shall be designed and supported so that equipment can be dismantled or removed with a minimum number of temporary supports and without dismantling valves and piping other than removing spool pieces or reducers adjacent to the equipment connections. Clearances shall permit installing blind flanges against block valves on hazardous fluid lines. Arrange piping so that the pump impeller can be removed without removing piping. Piping shall also be supported and routed so that when the bolts are removed from the pump suction and discharge piping no spring will occur. Valves in pump discharge lines shall be located as close to the pump nozzle as practicable. All centrifugal pumps shall be equipped with a check valve in the discharge line. Where there is a possibility of hydraulic shock in lines, a non-slamming type check valve shall be used (specified on the P&ID’s), and support loadings checked accordingly. All valves adjacent to pumps should be accessible. Valve hand wheels and stems shall not interfere with removal of pumps or extend into operational passageways. Pumps should normally be provided with a temporary suction strainer unless a permanent strainer is called for. All strainers shall be indicated on the P&ID.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 24 OF 39
Where “hat” or cone type strainers are used, the apex of the strainer shall face the direction of flow and will be installed inside a removable pipe spool, that allows cleaning and replacement. Piping support not to be placed on the cone filter removable spool. Suction piping shall be designed to enable the temporary strainer to be easily installed or removed without springing the pipe. The use of a ‘bath tub type’ temporary strainer should be considered where removal of piping will be difficult or to avoid potential nozzle re-alignment problems. Pipe supports around suction and discharge piping shall be discussed with the civil/structural lead Engineer to minimize steel and foundations. Any overhead electrical supports around pump groupings shall discussed to combine with piping supports in the planning and layout stage of the project. Use of common (previously planned) support steel shall be explored prior to adding support steel for pump piping. Pipe supports on reciprocating pumps should be clamp type and not welded to the pipe in order to minimize the potential of fatigue fracture at the support weld. All main pumps as a minimum to have sunshade.
12.4 Compressors
Compressor piping should fall continuously from any inter-stage coolers to the suction knockout drum. Compressor suction piping between the suction knockout drum and the compressor should be designed to prevent the possibility of trapping or collecting liquid. Piping shall be routed so that any condensate falls back from compressor suction nozzle to the suction knockout drum when possible. Consideration should be given to the inclusion of a drip leg on any suction line that does not drain to the suction knockout drum, i.e. on compressors with bottom nozzle orientation. The use of drip legs must be approved by process. The straight length requirements for inlet and outlet piping shall be as follows:
Inlet Piping
Type of Compressor
Opening preceded by Min. Straight length before Inlet Nozzle.
Centrifugal Compressors, axial compressors or combinations thereof and compressors with side stream outlets
Straight pipe
Elbow
Reducer
Valve
Flow device
3D
3D
3D or as indicated on the P&ID
10D
5D
Outlet Piping
Type of Compressor
Opening followed by Min. Straight length after Outlet Nozzle
Centrifugal Compressors, axial compressors or combinations thereof and compressors with side stream outlets
Straight pipe
Elbow
Reducer
Valve
Flow device
3D
3D
3D or as indicated on the P&ID
5D
5D
Temporary strainers, if required, shall be as close to the compressor as possible, unless the P&ID indicates otherwise.
Compressor suction piping shall be designed to enable the temporary strainer to be easily installed or removed without springing the pipe or removing any of the pipe supports. Suction line silencers shall also be located upstream of the suction strainer as close to the compressor suction connection as possible.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 25 OF 39
If two or more compressors are combined, their suction pipes should enter at the top of the header, except that suction pipes at least one pipe size smaller than the header may enter at the side of the header. Compressor suction and discharge piping shall be supported at locations determined by stress analysis. Where check valves are called for in the discharge piping of centrifugal compressors, the valve shall be located downstream but as near as possible to the recycle line, the recycle line take off should be as close as possible to the discharge nozzle of the machine. For gas compressor discharge piping where there is a possibility of reverse flow conditions causing vibration or possible damage to the compressor, a non-slam type check valves should be used, this requirement should be specified on the P&ID.
When pickling or chemical cleaning of compressor piping is required, it shall be noted on the detail
Isometric. Special consideration should be given to the location of field welds in compressor suction and discharge piping with respect to achieving the required flange/nozzle alignment required by the compressor vendor. A compressor piping erection procedure based on the compressor vendor nozzle alignment criteria with input from the COMPANY and fabricator should be developed.
Reciprocating compressors needing to undergo an acoustical study shall be designed as early as practical with routing, supports and stress analysis performed prior to sending to the acoustical study supplier. Piping shall be supported so as to minimize dead load on compressor nozzles and to ensure piping loads and moments within allowable limits. In order to prevent transmission of vibrations to a compressor house, main compressor process lines shall not be supported or connected to the building structure. If compressor is not located inside shelter, a dedicated sunshades for local instrument and panels, etc… shall be provided.
12.5
Towers and Columns
The angle of orientation of vessel nozzles is measured clockwise from Plant North being 0°.
Nozzles, manways, instrument connections, etc. shall be oriented to suit the requirements of the
Process/Mechanical data sheets and to avoid interference with internal down comers, baffles, trays, etc. Inlet nozzles shall be arranged to avoid impingement on the vessel wall, or against any instrument connections. Lines connecting towers and control valve manifolds at grade or platform levels shall be flexible enough to absorb vertical expansion so as to avoid the use of spring support at the manifold. Piping around vertical vessels shall be adequately supported with allowances for expansion and contraction of the vessel and piping without making excessive use of spring supports. Vessel clip requirements shall be established and notified to the vessel group or supplier as early as possible on the project. Vertical lines at vessels shall preferably be run close to the vessel shell to facilitate support. Where feasible, lines should be grouped in a straight line radially from the vessel, to allow for single support members.
Consideration shall be given to Vessel insulation requirements. Where possible, block valves should be located directly against the vessel nozzles, care should be taken
to ensure there is adequate clearance for stud bolt withdrawal. Platforms on towers and vessels are to be kept to a minimum consistent with adequate access to manways, hand holes, blinds, davit operation, control valves, valves 2”NPS and above, level instruments and gages, and relief valves. Access to valves 2” NPS and smaller may be from a permanently attached ladder.
Nozzles with piping only need not be accessible by permanent platforms. Towers with removable internals and with a top platform at 40m and above shall be provided with a davit. Manway elevations should be between 750mm and 1100mm from bottom of manway to the platform levels. Manway davits/hinges shall be provided and shall be oriented so that the manway cover opens away from
the platform ladder.
Manways shall be located to give the best possible access to tower drop-out areas so that tower internals
require minimum handling to the vessel lifting davit.
Check valves, where indicated on the P&ID’s, shall be installed as close to the nozzle as possible. Refer
to paragraph 9.2 for details on check valve locations.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 26 OF 39
All vessels and tower drains discharging into the oily water drain system shall have permanent piping arranged to permit visual observation of flow into a drain hub.
12.6 Drums
Elevations of horizontal drums are set considering drum diameter, support type, NPSH, bottom outlet, sump length (if required). The final access line elevation should be rounded up to an even dimension. Fixed and sliding end supports shall be arranged to benefit from the growth of the drum vs. the growth of any piping to and from the drum. Level instrument nozzles shall be located furthest from the inlet as possible, however on the high-level side of the weir if one is required. Pressure instrument connections shall be in the vapour space, preferably on the top Platforming shall be kept to a minimum for top and side accessibility. Early layout may allow incorporation of Platforming support to be included with the supports for drum.
Drums containing sumps elevated in structures shall be considered carefully to allow access to bottom of
sump outlet and level instruments on the sump. If there is a requirement for straight lengths at vessels with internal distributors and there is insufficient space consider using straightening vanes, this must be approved by the piping lead and the process group
12.7 Heat Exchangers
Heat exchangers with removable tubes or plates must have adequate space provided for the withdrawal of
the tube bundle or plates and for the tube bundle removal equipment. Brazed Aluminum Heat Exchangers (BAHX) condenser should be installed with adequate space and accessibility to allow withdrawal of the whole equipment if needed.
Heat exchanger piping shall be designed in a manner that will leave both shell cover and channel ends
free of overhead obstructions, so that maintenance facilities are not impaired. Valves shall not be located directly on top of channel nozzles which would cause obstruction when removing channel ends. Piping connected to shell and tube heat exchanger channel box shall be self-supported or provided with permanent supports so that the channels can be removed without having to provide temporary supports for the piping.
Design the piping to provide wrench room for unbolting exchanger channels. Maintain 150mm min.
clearance between the following components: Pipe flanges and the exchanger shell or insulation; Pipe or insulation and the exchanger flanges. Arrange the Channel piping with a removable spool between the exchanger and the block valves so that vessel full access is available for bundle pulling and tube cleaning.
Reboiler vapour return piping shall be free draining and drain towards the reboiler.
Thermosiphon reboilers shall be located as close as possible to the columns they serve. The piping runs shall be as short as possible, dictated by process and mechanical stress requirements. Thermosiphon outlet piping shall not include any pockets or downward sloping sections. Reboiler return piping shall be free draining. For vertical thermosiphons, including printed circuit and plate-fin exchanger types, the reboiler return piping shall contain no more than one 90 degree long radius elbow and one horizontal section of minimum length. Vertical thermosiphon type reboilers are usually supported by the tower and are located to be accessible for maintenance. Where the reboiler is too large to mount directly on the column, a support structure should be positioned close to the process column. Care must be taken to allow for the removal of any tube sheet etc. and this may require additional platforming local to the reboiler, which should also be utilized for instrumentation access.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 27 OF 39
Elevations of heat exchangers shall be kept to a minimum but should be of sufficient height to allow bottom lines from the exchangers to clear grade or platform, and to allow for the installation of drains. Apart from where it is necessary to elevate exchangers for process requirements, elevations shall generally be determined by the lowest allowable B.O.P, (bottom of pipe), of the largest diameter line from the bottom exchanger then rounded up so the centerline of the bottom exchanger is to the nearest even dimension. Include removable pipe spools at the nozzles of Printed Circuit Heat Exchangers to provide access to block faces for cleaning through the nozzles. Include removable pipe spools at the nozzles of Brazed Aluminum Heat Exchangers if needed to allow dismantling.
Where possible, piping or check valves on coolers shall be arranged such that the coolant will remain in all
units on loss of cooling medium supply. Provisions shall be made for draining all coolant from a blocked exchanger. The fixed and sliding saddle of the horizontal shell and tube heat exchanger shall be decided in such a way that helps releasing the expansion/contraction of the connected piping. In a typical exchanger layout with all exchanger piping running into the rack, the fixed end should be located on the shell side support farthest from the channel end and closest to the rack, to minimise differential thermal expansion. Enough space shall be kept between adjacent heat exchanger inlet and outlet valve manifolds.
12.8 Air Coolers
Fixed point of the air cooler is to be agreed with the seller as early as possible.
Nozzle and piping loads of air cooler piping is to be transmitted to and agreed upon by supplier as early as
possible. Prior to purchasing the equipment, the sliding end of coolers (on multi cooler layouts) to be carefully analysed to correspond with the piping movements of the inlet and discharge sides in order to eliminate stress loops. This requires early coordination with the cooler vendor, mechanical engineer, piping design, stress engineer and structural. If it is possible to set the coolers correctly large savings in pipe routing are possible. Pipe supports should not be attached to the cooler support frame without the agreement of the air cooler supplier. An access platform shall be provided at both ends of the tube bundle for maintenance purposes, even if the air cooler has an even number of passes and the inlet and outlet nozzles are at the same end. Preferably supplied by the air cooler supplier Air cooler fan drivers must be accessible from a platform. Air Coolers are either positioned over pipe racks with access from a common access walkway above the pipe rack or located in a separate row outside the main equipment row, remote from the central pipe rack, with a separate access walkway beside the units. Stair access to the air cooler walkway should be provided at each end, with additional intermediate access if walkways exceed egress limits. The access walkways should connect to local platforming directly under the units, for maintenance of both motors and fans (from top for Induced draft fans). The fin fan manufacturer, who supplies the necessary lifting/handling equipment, often supplies this associated platforming required for operational and maintenance of cooler motors, the fans, belts etc. Provision maintainable/removable parts like motor trolley for motor maintenance etc. shall be provided. Equipment shall not be located above air coolers. Location of air coolers shall be such that hot air emitted is not a hazard or an inconvenience to personnel and has no adverse effect on the operation of adjacent equipment. To account this, these shall be located downwind of the facilities to take advantage of the prevailing wind to disperse hot air away from operating areas.
for material handling of
Where there are many air coolers mounted along the length of the pipe rack, care must be taken in positioning them relative to each other. If positioned too close to each other, re-circulation problems may occur, where one set of fin fans exhaust air may be sucked into the next fin fan air cooler inlet for example drawing in warm air instead of cool air.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 28 OF 39
Wherever possible air coolers should be grouped with a common elevation. Air coolers with different fan
intake elevation shall not be located adjacent to one another to avoid hot air circulation. In case of forced draft air coolers, the arrangement and size of the permanent maintenance access platform beneath the fans shall not restrict the air flow to the fans. Tube bundles to be removed shall be handled by crane. Equipment, structures and piping must not interfere with access by this crane. To avoid hot air impact during operation & maintenance, PSVs and any other valve assemblies not to be located at higher elevated platforms in the vicinity of Air Cooler (such on platform for air cooler bundle access platform). Air-cooler piping should be arranged symmetrically to provide uniform distribution to inlet manifolds. In addition, the connecting piping shall be designed so that small dimensional errors in construction can be accommodated.
12.9
Filters
Filter piping layout shall be configured to allow cartridge removal, with minimum disassembly. All bypass and switching valves shall be operator accessible either at grade or by providing platforms. Filters shall have adequate designated area and platforms where required for filter cartridge to be removed.
12.10 Storage Tanks
The number of pipes contained inside a diked area shall be minimized and shall be routed in the shortest practicable routing from the tank to the dike wall. Where practical, the pipes shall be grouped together. Piping routed inside the dike wall shall be routed above the liquid level of the containment area. Isolation valves for low temperature and cryogenic tanks shall be located inside the diked area. Pipes connected to tanks shall be sufficiently flexible to cope with thermal expansion/contraction, tank settlement, the outward movement of the shell and the inclination of nozzles under hydrostatic load. The first pipe support shall be located sufficiently far away from the tank to allow for tank settlement and for the thermal expansion of any vertical pipe leg. If tank settlement above an acceptable limit is expected, precautions should be taken to cope with it, e.g. by using loops, spring supports, in some circumstances the use of expansion joints may be considered. For tank pipes 20” NPS and larger, spring or balanced supports may be considered. Piping shall be connected and supported after hydrostatic testing of the tank. The following distances may be used as a guide:
Pipe Size and Appropriate Distance
Nominal pipe size
4” and smaller
6”
8”
10”
12”
14” – 18”
20” and larger
Distance between tank nozzle and first support
5m
6m
7m
8m
9m
10m
12m
There shall be access to manways, mixing nozzles, drains and other facilities on the tank. Small bore utility piping required for more than one tank may be routed along an interconnecting overhead walkway, if available. Valve manifolds should be located outside the dike wall.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 29 OF 39
Tank nozzles, including product drains and water draw-off connections, shall have block valves. Drains for cleaning purposes only require blinding off.
12.11 Wall thickness discrepancy between equipment butt-welded nozzles and piping
When equipment nozzle wall thickness is 1.6mm greater than the connected piping wall thickness in butt- welded nozzles, a 1:3 taper bore will be redlined on the supplier-fabricator drawing. If the piping wall thickness is 1.6mm greater than the equipment nozzle wall thickness, 1:3 taper bore will be indicated on the face of the isometric.
12.12 Packaged Equipment Piping
The piping layout within equipment skids supplied as a complete package shall be the responsibility of the equipment package supplier while maintaining all requirements related to piping design, layout, spacing etc. as defined in this specification. The package supplier should restrain all the piping at the edge of the skid by line stops, guides or anchors as required by the piping design. The tie- in points on packaged equipment shall be brought to the edge of the skid and terminate with flanges. As far as possible utility connections, flare, vent and drains shall be terminated as single tie-ins at edge of the skid. The equipment and installations shall be shop assembled to the maximum extent practical, mounted and delivered onto a skid or on multiple skids so that erection at fabrication yard can be minimized. Large or fragile items which cannot safely be transported on the skid shall be removed after completion and shipped separately. Fabrication and Erection shall meet the requirements of RLNG-000-MT-SP-6301 – Specification for Pipe Fabrication and Erection. Prefabricated modules shall not be considered as packaged units and all requirements of this specification apply.
During FEED and in early stage of design, the area/space required for packages shall be fixed considering
allowance for growth during EPC stage. All Packaged equipment’s shall undergo reviews to demonstrate, safety access, operational and maintenance access including material handling aspects of individual components during the design stage of the project (e.g., like 3D model reviews, etc.).
12.13 Pipeline Pig Launcher / Receiver
Launcher and receivers should be positioned at the edge of the plant / platform and their doors should point directly away from the plant / outboard of the facility to reduce the possibility of damage from any projectiles. Impact wall shall be introduced if safe distances from other plant facilities are not available and agreed with COMPANY. Elevation of Pig traps to be decided to suit pigging operation requirement, loading of pigs and also based on elevation of drain nozzle from grade
Road access to the Pig Launcher / Receiver shall be provided. Proper access to nozzles and door shall be
provided. Laydown areas shall be provided for the loading / unloading of the largest intelligent pigs
Consideration shall be given to mechanical handling facilities for pigs like jib crane, pig trolley etc. Where a sight glass is specified on the drain line, sufficient space must be provided for observation of flow. The traps shall have a pressure indicator positioned so that it will be visible to personnel operating the pig trap closures. A spillage retention tray provided with drain shall be installed. The retention tray for the pig trap shall be sized according to the length and volume. Space for future Pig traps and its associated future pipeline approach shall be provided and number of future traps to be agreed with COMPANY.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 30 OF 39
13.0
LOADING AND UNLOADING FACILITIES
13.1 General
Raw materials and products may be transported to and from the plant by either road or by sea. Reference should be made to the relevant international and COMPANY codes and regulations for the transport of goods, both hazardous and non-hazardous. In all cases, local codes must also be reviewed for any requirements, which may be different from, or more stringent than, the recommendations in the standard codes.
RLNG-000-PI-BOD-0002 - Basis of Plant Layout document shall be followed for safe distances of these
facilities. A suitable firefighting system in line with HSE requirements, should be installed and two, separate and opposite, access routes provided for fire fighting vehicles. The loading / unloading bay areas should allow for free and safe access for personnel around all agreed differing sizes of tanker and the adjacent islands. Due to the possibility of spillage, the whole area should be paved, sloped away and should have the facility for wash down with a suitable drainage system.
13.2
Truck Loading
Road loading / unloading areas is generally located close to their storage facilities, but situated on the edge of the site, downwind of the process plant. The proposed routes of road and rail tankers etc. to loading / unloading areas should be established as early as possible, to determine overall road and locations of weighbridges, ticket offices, marshalling areas, gate houses etc. Truck loading racks for flammable and combustible liquids should be located near the plant gate to avoid truck traffic near process areas. Tank car loading racks for flammable liquids should be located to avoid road blockage when spotting rail cars, ensuring passage for fire trucks or other service vehicles at all times. Truck loading facilities shall be located close to product movement gate. Loading/unloading areas for road transport shall have adequate space for access for filling, parking and manoeuvring. A drive-through rack arrangement is preferred.
13.3
Ship Loading
Offshore Loading and ship berthing facilities shall be designed strictly as per applicable International Codes
and Standards to cover the following guidelines:
- Design criteria,
- Material selection,
- Tie-in methods,
- System reliability,
- Project costs and schedule.
Installation methods, Inspection requirements,
14.0
TIES-INS
14.1 General
An existing valve or flanged connection should be used to tie-in to existing piping systems wherever possible. Where an isolation valve or flanged connection is not readily available in the existing piping system, a hot tie-in connection (cut and weld type of tie-in connection) may be used.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 31 OF 39
14.2
Types of Tie-In
The types of tie-in connections typically used for the connection of new piping system with an existing piping system include: Cold tie-in connection for example flanged connection. Hot tie-in connection (for example cut and weld type of connection). Hot tap tie-in connection.
14.3 Hot Taps
Hot tap tie-in connection shall only be considered when both “cold tie-in connection” and “hot tie-in connection” cannot be executed on the existing piping system due to process operations limitations.
14.4 Additional Considerations
Special attention shall be paid by extensive site surveys when designing the tie-ins location on existing systems so as to minimize shutdowns resulting in loss of production. The new lines connected to the existing lines shall be supported to minimize the loads added on existing lines and shall take care of the flexibility of the new system considered as a whole. All new piping at tie-ins shall follow the new pipe classes as per RLNG-000-PI-SP-1022 - Specification for Piping Material Classes.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 32 OF 39
15.0 APPENDIX
15.1 Appendix 1: Ergonomics/ Accessibility – Ergonomic Valve Positioning]
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 33 OF 39
15.2 Appendix 1: Ergonomics/ Accessibility – Accessibility Requirements
Accessible From:
Items;
From Grade or Platform
By Permanent Ladder
By portable devices or scaffolding (maximum 3600mm above grade)
Control Valves, On-Off valves Safety Valves (except thermal relief) see para. 11.2 Battery Limit Valves. See para. 9.1 Operational Valves 3” and over. See para 9.1 Spectacle blinds Manways on vessels higher than 3600mm above grade Flow meters (except orifice and venturi type) Sample collection points Operational Valves 2” and smaller Level instruments on towers and vessels Pressure indicators Temperature indicators Handholes Sample take-off points Restriction orifices Check valves Pressure connections (except indicators) Temperature connections (except indicators). Manways on vessels with an elevation of 3600mm and below Non-operational valves 2” and smaller See Paragraph 9.1
Notes:
In addition to above accessibility requirements, considerations are to be made regarding maintenance requirements such as extra space for catalyst handling, lay-down areas, overhaul requirements, etc. Maximum use of available mobile equipment is to be implemented, otherwise permanent facilities such as hinge points; monorails, etc. are to be provided.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 34 OF 39
15.3 Appendix 2: Typical Pipe Rack Design – Typical Line Routing Diagram (Example)
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 35 OF 39
15.4 Appendix 2: Typical Pipe Rack Design – Typical Pipe Rack Layout Elevation
Future space calculation to be considered:
Min. 20% Future Space in total is required. These 20% should be by type of Piperack level (Process / Utility).
In case of several Process levels or several Utility levels, the 20% future space should be equally distributed as much as possible by type of piping levels (Process / Utility). However, the space distribution could be changed with the reasons justified by CONTRACTOR and approved by COMPANY (for example: from 10+10 to 15+5). The future installation of the piping shall be considered with minimum interaction to ‘live’ piping, especially for process ones. Any further space provisions shall not compromise with existing piping layout / constructability / maintainability etc.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 36 OF 39
15.5 Appendix 2: Typical Pipe Rack Design – Typical Pipe Rack Space Allocation Plan (Example)
RESERVED FOR PIPING
RESERVED FOR INSTRUMENTS OR ELECTRICAL SEE NOTES
RESERVED FOR ELECTRICAL
PIPE RACK COLUMNS
Notes:
- Piping to ensure accessibility to the instrument or electrical objects where applicable.
Adequate space for maintenance, access walkways, and escape routes to and from the unit area shall be maintained and modeled as soft space volumes in the CAD model early in the project
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 37 OF 39
15.6 Appendix 2: Typical Pipe Rack Design –Standard Pipe Spacing Guide 1
Table for Bare pipe to staggered flanges: refer to Piping Design Standards ref. RLNG-000-PI-DWG-0801
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 38 OF 39
15.7 Appendix 2: Typical Piping for Centrifugal Pump Suctions – Figure 1
Minimum Required Straight Pipe Length (L2) Before Pump Suction Inlet
(Refer Also to Figure 2)
Notes:
a.
For fittings with less than two pipe diameters required, consideration must be made for providing additional pipe length for ease of pump installation and removal.
b. The pump manufacturer is responsible for successful operation when it supplies fittings that are directly connected to pump, whether or not they can conform to requirements of this table.
c. Ball valve and gate valve d. Care must be taken when placing a butterfly valve from a fitting such as an elbow or tee. The disk should not be oriented such that it can channelize flow and thus exacerbate the non- uniform hydraulic conditions generated by the upstream fitting.
Information in Figure 1 is an excerpt from ANSI/HI 9.6.6-2009. In case of conflict, ANSI/HI-2009 will take precedence.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
RUWAIS LNG PROJECT
PIPING DESIGN BASIS
COMPANY DOCUMENT REF. CONTRACTOR DOC. REF.
RLNG-000-PI-BOD-0001 215122C-000-JSD-1300-0001
REVISION: 1
PAGE 39 OF 39
15.8 Appendix 2: Typical Piping for Centrifugal Pump Suctions – Figure 2
Notes:
e. The use of flow disturbing fittings on the inlet (suction side) of the pump needs to be carefully evaluated. Generally, pumps will have an un-interrupted and un-throttled flow into the inlet side (suction) nozzle, no flow disturbing fittings for some minimum length. Flow disturbing fittings should not be connected directly to the pump inlet without approval from the pump manufacturer. Flow disturbances on inlet (suction) side of the pump can lead to deterioration in performance (lower head and lower NPSHA), and damage leading to shortened impeller, mechanical seal, and bearing life (from cavitation, pulsation surges, and excessive radial and axial forces). Isolation valves, strainers, and other devices used in the inlet (suction) side of the pump will be sized and located to minimize disturbance of the flow into the pump (Figure 1). Table of §15.8 (Figure 1) presents the minimum length of straight pipe (dim L2 of Figure 2) required immediately upstream of the pump inlet (suction) nozzle. Failure to provide the minimum pipe length specified in Table of §15.8 (Figure 1) may lead to hydraulic and mechanical issues described in Note a. Double suction pumps are sensitive applications, because an elbow in the plane of the shaft mounted on the suction flange will direct more flow to one side of the impeller than the other.
f.
The terms of Contract / Agreement No: CON22-146 shall apply for any disclosure of this document to any third party.
Project: Q-32859 - NMDC - Ruwais Folder: RFQ Files