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Zuhair Fayez Partnership (ZFP)Zuhair Fayez Partnership (ZFP)

Industrial Division, Al-Khobar

Plant Layout and Piping Design Notes

Design Note No. Rev. Issue Date By

DN-01 A 16/11/07 A.MANSOUR

Subject : Piping Design Notes

Purpose of Design Note: To insure that the piping design complies with ARAMCOstandards.

The listed points below have been extracted from the following ARAMCOstandards:-

SAES-B-054 Access and Egress Requirements

SAES-B-055 Plant Layout

SAES-F-001

SAES-L-310 Design of Plant Piping

SAES-S-20

PIP PNE00001 Design of ASME B31.3 Metallic Piping Systems

04-SAMSS-001 GATE VALVES04-SAMSS-001 GLOBE VALVES

04-SAMSS-041 EXPANDING PLUG VALVES

04-SAMSS-051 BALL VALVES API SPEC6D

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1) Equipment regularly operated/maintained or operated in an emergency, such as valvehand wheels, instrumentation, controls, and their associated manifolds, the distance, iflocated outside the handrails, from a fixed walking/working surface to the operating pointshall be between 500 mm and 1500 mm vertically and a maximum of 510 mm horizontally.

2) Access for instrumentation, controls, and associated manifolds from a fixed ladder or fixedstairs to the operating point should not exceed 510 mm.

3) Vessel openings, such as manholes and inspection openings, the max vertical distance

from grade to the lower inside surface of the opening shall not exceed 3 m. At an elevationgreater than 3m above grade, a fixed, elevated walking/working surface is required, thelower inside horizontal surface of the manhole should not exceed 760 mm vertically abovethat walking/working surface.

4) For equipment such as blinds, heat exchanger tube sheets, heat exchanger bonnets andInlet/outlet block valves on relief valves and the relief valves that require access duringmaintenance, fixed walking/working surfaces shall be provided.

5) Valves not regularly operated shall be accessed from portable platforms, portable stairs,portable ladders, or temporary scaffolding if access from fixed walking/working surfaces orfixed stairs is not provided.These valves consist of the following:

A. Valves used exclusively for tie-in purposes.

B. The first block valve in a line to a utility header.

C. Vents and drains used for steam-out, purging, or pressure testing of piping.

D. A fixed stairway shall be provided as primary access to and egress from, eachelevated working area in daily use. A stairway shall also be provided if materials,tools or other equipment must be carried for operating or maintenance, or if there isa potential for exposure to injurious chemicals or material at the elevated workingsurface.

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7. A secondary means of egress (which may be either a fixed ladder or a fixed stairway) shall beprovided for each elevated working surface if the location is 3 m or more above grade, andhas 19 m or more area. This secondary means of egress shall not be more than 25 mhorizontally from an area where operating or maintenance personnel may be working, andshall be located such that an alternative route of escape to a place of safety is provided.Exits to safety from such areas shall be located as far from each other

8. Dead ends in elevated work areas shall not be over 7.6 m long.

9. Minimum clear width of walking/surfaces, stairways and stiles shall be 760 m

10. Minimum clear width where a working area is needed such as in the front of a manhole, theend of a heat exchanger, channel and tube bundle, or around rotating equipment. shall be910 mm 11. The minimum clearwidth of aisles shall be 1020 mm. (An aisle is personnel walking space around equipmentat grade level.)

as is practicable.

12. The minimum headroom above walking/working surfaces shall be 2030 mm.

13. The vertical clearance above any stair tread shall be a min. 2030 mm.14. Trolley beams or davits shall be provided at the top of columns with internals and/or with

flanges over 100 mm (nominal) or weighing over 36 kg.

15. Manhole covers shall be hinged or equipped with davits.

16. Fixed stairs shall be installed at an angle of 30 to 45 degrees to the horizontal. Whereverpractical, fixed stairs shall be installed at an angle of 37 degrees to the horizontal with arise of 190 mm and a tread run of 254 mm.

17. A stairway landing shall be provided for every 3.7M of vertical rise of a stairway whereverpractical. Where this is not practical this can be increased to a maximum of 5M.

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18. Fixed ladders shall be side-step design.

19. Analyzer houses shall be located with free access of 3 m on all sides. For details see SAES-B-014 and SAES-J-502.

20. Atmospheric exhausts from steam turbines, and combustion gas turbines, shall be located so

that they will not present a hazard to personnel and/or equipment on the same platform oron adjacent working platforms. They shall be at least 3 m higher than any platform oraccess within a horizontal distance of 7.5 m.

21. Primary roads should be 8 m wide, with 2 m shoulders on each side Secondary roads shouldbe 7 m wide, with 1.5 m shoulders on each side. Access ways should be a minimum of6.1 m wide. For primary and secondary roads the following clearspaces from the edge of the shoulder shall be maintained:

a.5 m from pipe ways or onsite equipment, with barriers placed between road and pipeline, toprevent vehicle/equipment collisions.

b. 7.5 m from high risk equipment such as pumps handling flammable materials, compressorshandling flammable gases, equipment operating at over 315C, and furnaces.

c. 9 m below overhead obstructions, viz: overhead pipeways, electrical transmissionlines, and other similar obstructions to heavy transportation equipment.

22. The piping layout shall assure safe operation, ease of construction, provide adequate accessfor maintenance activities, minimize consequence due to fire, and avoid congestion.

23. The pipe size, layout and supports shall be designed such that all hydraulic requirements aremet in terms of pressure drop and required through put.

24. The minimum spacing between lines supported on sleepers or pipe racks shall be as shown onStandard Drawing AC-036207.(Attached)

25. Above-grade piping shall be supported to provide a minimum of 300 mm clearance betweenbottom of the pipe and the finished grade.

26. A minimum clearance of 50 mm shall be provided for inspection and freedom of pipemovement between above ground piping crossing with any structure (including pipe supportstructure). This clearance is also required for above ground piping crossing with another pipe.

27. Branch connections, 4 inch and smaller, including drain and vent valves and drip legs of allsizes, shall be located at a minimum horizontal distance of 610 mm (24 inches) from any fixedobstruction. This requirement does not apply to that part of the support which is attached directlyto the piping, such as horizontal and vertical dummy extensions.

28. Hose connections, where applicable, shall be positioned at elevation not higher than 1200 mmabove finished plant grade or above platform of multilevel equipment but not lower than 600 mm.They shall be pointing 45 degrees downward. The piping shall be securely bolted to a supporting

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structure and have adequate access. Utility connections shall be installed with minimum 150 mmclearance between each other.

29. Each utility take-off connection shall be located at the top of the horizontal main header orauxiliary header. Root valves shall be provided for each utility take-off connection from a mainheader or auxiliary header which can not be taken out of service without shutting down a completeprocessing unit or operating facility.

30. Instrument air take-off connections to the plant utility station shall always be provided with rootvalves.

31. Each utility line shall be provided with an isolation valve just upstream of the specified hoseconnector at the termination.

32. The steam line shall have a steam trap and shall be insulated for personnel protection exceptfor utility steam take-off lines. Utility steam take-off lines shall be insulated but shall not beprovided with steam traps. Utility steam stations located above the utility steam header shall beself-draining towards the utility steam header. Utility steam lines to utility stations below the utilitysteam header shall be allowed to gather steam condensate, which is removed by operationsbefore applying the utility steam.

33. Piping layouts in all services shall be designed to eliminate the presence of dead legs.

34. Blind flanges shall be used as end closures on flanged ends and valves, unless end caps areclearly indicated by design necessity.

35. Jackscrews shall be used to facilitate flange separation for maintenance. Joint assemblies thatoften require frequent separation include orifice plates, spectacle plates, spacers, screens, anddropout spools. Piping layout shall be designed such that flanges can be separated withoutexcessive force. Jackscrews shall be accessible from both sides of the pipe. For orifice flanges,jackscrews shall be installed at three- and nine-oclock positions.

36. Check valves in vertical piping shall be installed for upward flow only and shall be installed with

a drain connection immediately above the check valve. 37.For all sizes NPS 3 and above, a turbulence-free minimum distance of five pipe diametersupstream and two pipe diameters downstream of every check valve should be maintained. Nopipefittings (e.g., elbows, reducers, tees, etc.) or flow-restricting devices (e.g., orifices, controlvalves, etc.) should be installed in these zones. Valves in intermittent service and valves in skid-mounted systems are exempt from these requirements.

38. Instrument air branch lines shall be taken from the top of the header. Block valves are requiredfor branch connections less than NPS 2 and shall be located at the header.

39. Plant air branch lines shall be taken from the top of the header. Block valves are required forbranch connections less than NPS 2 and shall be located both at the header and at theequipment.

40. All aboveground cooling water supply and return branch lines shall be connected to the top ofthe headers.

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41. Utility water branch lines shall be taken from the top of the header. Block valves are requiredfor branch connections less than NPS 2 and shall be located both at the header and at theequipment.

42. Steam headers shall run level or shall pitch downward in the direction of steam flow. A verticalrise required in the direction of steam flow shall be via a vertical leg equipped with a drip leg at thelow point.

43. Steam branch lines shall be connected to the top of the headers. Branch lines shall run level or

pitch downward in the direction of the steam flow. A vertical rise required in the direction of steamflow, downstream of the connection to the steam header, shall be via a vertical leg equipped with adrip leg at the low point.

44. Block valves shall be provided in the branch lines from the steam headers located at andabove the elevation of the steam header and installed in such a manner that no pocket is formedwhere condensate may collect.

45. Drip legs equipped with steam traps shall be installed at the bottom of steam headers asfollows:

a.At dead ends of steam headers and branch linesb. At low pointsc. Upstream of risers and vertical legsd. Upstream of expansion joints and raised expansion loopse. Upstream of block, reducing, and control valvesf. At intervals of approximately 150 feet (45 m) in straight, horizontal steam lines (i.e., withoutnatural drainage points), but not greater than 300 feet (90 m)

46. Spectacle Blinds shall be installed in the horizontal part of the line where possible.

47. Nominal pipe sizes NPS , 1, 2, 3, 5 and 22 shall not be used, except as required tomate with equipment connections. Where necessary to match a manufacturers equipmentconnection a reducer must be employed immediately to increase to the next available acceptable

pipe size.For nominal pipe sizes greater than NPS 24 pipe sizes shall, wherever possible, increase inincrements of 6 inches up to and included NPS 48. Above NPS 48 nominal pipe sizes shallincrease in increment of 4 inches.

48. All flanges Class 900 and above shall be supplied with Ring Type Joint.

49. In Sour service socket weld or threaded fittings shall not be used. Butt weld fittings shall beused for all sizes.

50. Manways should be located at the end of a platform or in such a position that they do notencroach on the escape route when in the open position.

51. Gear Operated Valves :

Valves shall be actuated by gear operator as specified below:

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Gate Valve

Cl 150 24

Cl 300 16

Cl 600 8

Cl 900 & Higher 6

Globe Valve

Cl 150 14

Cl 300 10

Cl 600 8

Cl 900 6

Cl 1500 4

Ball Valve

Cl 150 6

Cl 300 4

Cl 400 & Higher 3

Plug Valves (EXPANDING)

Cl 150 8

Cl 300 6Cl 600& Higher 4

Butterfly Valves Cl 150/300 Refer to Piping Class

52. Block valves used for flare systems shall be installed such that valve stems are oriented 45below horizontal and shall not pose an obstruction to normal personnel access in the walkway.

53. Catch basins, or other collection points in each drainage area shall not be located directly

beneath any equipment. They shall be located such that the drainage path from a source ofspillage does not pass beneath any other equipment or vessels containing hydrocarbons, pipeway,

pipe rack, stairs or ladders.

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