Section 5 — Piping

Selection of Piping Components and Materials

IPE Engineering Practice IPE-EP-5-2-1

Document number: IPE-EP-5-2-1 · Section: 5 — Piping

SCOPE

• This Practice covers requirements for the selection and application of piping components and materials for use in refineries.
• Supplemental requirements including data to be furnished by the Purchaser, the Manufacturer’s responsibility, documentation, marking, packaging and shipping for pipe and piping components are covered in EP 5-2-4.
• The requirements in this Practice establish the basis for the IPE Piping Standard, and shall be followed when additions, changes, or new specification standards are necessary. The IPE Piping Standards are listed in EP 5-2-3.
• Any deviation from this Practice must be approved by the procedure described in EP 1-1-3.
• An asterisk (*) indicates that a decision by the Owner’s Engineer or Owner is required, or that additional information is furnished by the Purchaser.
• A revision bar indicates all changes made to this Revision.

2.0 REFERENCES

The latest edition of the following standards and publications are referred to herein.

STANDARDS AND PUBLICATIONS

STANDARDS AND PUBLICATIONS (CONTINUED)

STANDARDS AND PUBLICATIONS (CONTINUED)

STANDARDS AND PUBLICATIONS (CONTINUED)

DEFINITIONS

• Aggressive Environmental Service (AES) - Process services which result in material degradation such as cracking, scaling, blistering, and severe pitting and/or corrosion. Examples of such services are hydrogen service, wet hydrogen sulfide, cyanides, caustic, amine, and hydrofluoric acid. AES process fluid are defined in EP 10-2-1.
• Category D Fluid Service - A fluid service, as defined in accordance with ASME B31.3, in which all of the following apply.
• The fluid handled is non-flammable, non-toxic, and not damaging to human tissues as defined in paragraph 300.2 of ASME B 31.3.
• The design gauge pressure does not exceed 150 psi.
• The design temperature is from -20 F through 366 F.
• Category M Fluid Service - A fluid service in which the potential for personnel exposure is judged to be significant and in which a single exposure to a very small quantity of a toxic fluid, caused by leakage, can produce serious irreversible harm to persons on breathing or bodily contact, even when prompt restorative measures are taken.
• Contractor - Company or business that agrees to furnish materials or perform specified services at a specified price and/or rate to the Owner.
• Fluid Service - A general term concerning the application of a piping system, considering the combination of fluid properties, operation conditions, and other factors which establish the basis for design of the piping system.
• High Pressure Fluid Service - A fluid service for which the Owner specifies the use of Chapter IX of ASME B31.3 for piping design and construction; see also paragraph K300 of ASME B31.3.
• Hydrogen Rich Service - A service defined as a combination of hydrogen partial pressure and temperature at or below the curve for carbon steel per Figure 1 of API Publication 941, latest edition, and with a hydrogen partial pressure greater than 100 psia.
• Hydrogen Service - A service defined as a combination of hydrogen partial pressure and temperature above the curve for carbon steel per Figure 1 of API Publication 941, latest edition.
• Inspector - A Inflection Point Engineering, LLC appointed engineer or inspector.
• Manufacturer - The recipient of a direct or indirect purchase order for materials and/or equipment. In this context, a direct order is one issued to a manufacturer by a contractor or the Owner. An indirect order is one issued to a manufacturer by a vendor (recipient of a direct order) for materials, fabricated components, or subassemblies.

• Normal Fluid Service - A fluid service pertaining to most piping covered by this Code, i.e., not subject to the rules for Category D, Category M, or High Pressure Fluid Service, and not subject to severe cyclic conditions.
• Owner - Inflection Point Engineering, LLC.
• Owner’s Engineer - A Inflection Point Engineering, LLC appointed engineer.
• Pipe Nipple - A short piece of pipe with or without threaded ends.
• Purchaser - The party placing a direct purchase order. The purchaser is the Owner’s designated representative.
• Service Cyclic Conditions - Thermal Load conditions producing significant fatigue effects as defined in ASME B31.3.

GENERAL

• (*)All piping components shall conform to the requirements of this Practice, ASME B31.3 or ASME B31.1 as applicable, and local jurisdictional regulations. In case of conflict among these requirements the most stringent requirements, as determined by the Owner’s Engineer, shall govern.
• (*)The use of piping components made to dimensional standards not listed in ASME B31.3 or ASME B31.1 requires approval of the Owner’s Engineer unless specifically approved herein. Any valves, fittings, flanges, or unions made to such standards shall be marked in accordance with MSS SP-25.
• (*)The use of component and material standards with a date other than the one referenced in the latest edition or addendum of ASME B31.3 or ASME B31.1 requires approval of the Owner’s Engineer.

MATERIALS

• General
• All materials used for piping components shall be per the requirement of this Practice and ASME B31.3 or ASME B31.1, as applicable.
• The use of reclaimed metallic and non-metallic materials is prohibited.
• (*)The use of materials at temperatures above or below those for which allowable stress values are shown in ASME B31.3 requires prior approval from the Owner’s Engineer.
• Metallic Materials
• Material selection of all metallic pipe, fittings, forgings, and valves shall be per TABLE 1.
• Piping materials and PWHT requirements for Aggressive Environmental Service shall be in accordance with the requirements of EP 10-2-1.
• Supplemental material requirements for carbon steel, low alloy steel, stainless steel and high alloys are stipulated in EP 10-2-2. These requirements include items such as carbon equivalent, chemistry control, heat treatment and Charpy impact requirements.
• Material selection for tubing shall be per TABLE 9.

• (*)The use of materials with greater than 70,000 psi minimum tensile strength for pressure containment requires written approval from the Owner’s Engineer.
• Nipples made from bar stock are prohibited.
• Limitations on the use of copper, and copper bearing alloys, shall be as given below for the following services:
• Ammonia: Alloys with a copper content greater than 50% shall not be used in ammonia service or in aqueous solutions containing ammonia where the pH exceeds 8.5.
• Caustic and alkaline: Alloys with a copper content less than 85% shall not be used.
• Acetylene: Alloys with a copper content greater than 50% shall not be used in services where acetylene in a wet environment is present.
• Copper, aluminum, and their alloys shall not be used for piping components in flammable service, except that aluminum may be used in ASME/ANSI B16.5 Classes 150, 300, and 600 for temperatures below -50F.
• (*)If aluminum castings (for example, valve bodies) have been subjected to welding or thermal cutting, their ratings and/or allowable stresses require approval from the Owner’s Engineer. Use of aluminum castings other than ASTM B26 Grade 356 T6 requires prior approval from the Owner’s Engineer.
• (*)Lead, tin, and their alloys shall not be used in flammable fluid services. They shall not be used in other pressure piping without prior approval from the Owner’s Engineer.
• Ductile iron pipe shall only be used in fire water or underground cooling water services. Ductile iron pipe shall be centrifugally cast and suitable for a minimum working pressure of 125 psig and a design pressure of 150 psig.
• Low melting point alloys, such as brass or bronze, shall not be used in flammable material or combustible liquid services. Aluminum alloys are permitted in cryogenic service.
• Supplemental material requirements for piping in Hydroflouric Acid (HF) Service are covered in EP 5-10-1 for Phillips HF Units and EP 5-10-2 for UOP HF Units.
• Non-Metallic Materials
• (*)Unreinforced Teflon and glass-reinforced Teflon shall not be used where they would be exposedto temperatures above 350 F and 450 F respectively. However, when used as the filler for spiral wound gaskets, unreinforced Teflon may be used to 450 F. Use of Teflon filled with or reinforced by other materials requires prior approval from the Owner’s Engineer.
• (*)Non-metallic materials shall not be used for pressure-containing piping components (other than gaskets, packing, and valve seats) in flammable services. They shall not be used in toxic service without prior approval from the Owner’s Engineer.
• Requirements for plastic piping are covered in EP 5-9-1.
• Requirements for plastic-lined pipe are covered in EP 5-9-2.
• Requirements for cement-lined pipe are covered in EP 5-9-3.
• Identification
• (*)All pipe materials shall be color coded by the Contractor to provide expedient identification for storage and issue. The color coding system shall be per EP 15-1-5.

• Valves shall be marked in accordance with EP 5-3-21.

PIPING

• General Requirements
• Selection of piping materials shall be per TABLE 1.
• Pipe dimensions shall be in accordance with the following:
• ASME/ANSI B36.10 for welded and seamless wrought steel pipe.
• (*)ASME/ANSI B36.19 for stainless steel pipe; stainless steel pipe per ASME/ANSI B36.10 is acceptable if approved by the Owner’s Engineer.
• All pipe threads shall conform to ASME/ANSI B1.20.1 taper pipe threads. Butt weld preparation shall conform to ASME/ANSI B16.25.
• Pipe in sizes NPS 2 and smaller shall be furnished with square cut ends unless otherwise specified by the Purchaser. Pipe greater than NPS 2 shall be furnished with both ends prepared for buttwelding in accordance with ANSI/ASME B16.25, Figure 2A or 3A as applicable. Flame cut weld bevels are not permitted.
• Pipe shall be furnished to the specific or random lengths as specified by the Purchaser. Couplings or jointers shall not be used for pipe sizes NPS 24 and less. Jointers for pipe NPS 26 and larger require the Purchaser’s approval. Girth welds shall be in accordance with the material standard and ASME B31.3.
• Unless otherwise specified by the Purchaser, the length of pipe nipples shall be either 3 or 6 inches as specified in the pipe class per EP 5-2-3. All burrs shall be removed from pipe

nipples. The use of “close” nipples (pipe nipples that are threaded along, or nearly along, the entire length of the nipple) is strictly prohibited.

• All plates used in the fabrication of pipe having less than a 6 to 1 reduction from the original conventionally cast ingot or continuously cast slab shall be subject to ultrasonic examination using an angle beam technique. Examination shall be performed in accordance with ASTM A- 577.
• When pipe is cold expanded, the amount of expansion shall not exceed 1-1/2 percent of the outside diameter of the pipe. Materials, such as austenitic stainless steels, which undergo a phase transformation by cold working shall not be cold expanded.
• (*)The use of non-metallic pipe or plastic lined metallic pipe requires prior approval from the Owner’s Engineer. Requirements for non-metallic piping and plastic lined metallic piping shall be in accordance with EP 5-9-1 and EP 5-9-2 respectively.
• Size Limitations
• The minimum size of piping connections to vessels, large lines, etc., shall be NPS 3/4 for hydrocarbon service, except that atmospheric vent and drain connections from small equipment, certain instrument connections, and steam tracing connections may be NPS 1/2. The minimum size of pipe downstream of first block valve shall be NPS 1/2.
• The minimum bore of piping shall be 0.250 inch.

• Pipe sizes of NPS 1/8,1/4, 3/8,1-1/4, 2-1/2, 3-1/2, and 5 shall not be used. Mechanical equipment or instrument connections in these sizes shall be changed to a permissible piping size immediately adjacent to the equipment.
• Corrosion Allowance And Wall Thickness
• The wall thickness of piping shall not be less than that required by ASME B31.3 or ASME B31.1, as applicable. The design conditions used to compute the wall thickness shall be established using EP 5-1-1.
• (*)Dead ends (piping with little or no flow) shall be avoided especially for piping conveying fluids that may form a corrosive condensate. If dead ends cannot be avoided, the piping shall receive special consideration. If the fluid is determined by the Owner’s Engineer to be more corrosive under these conditions, the piping shall be constructed of components made from materials that will withstand the corrosion or from components with extra corrosion allowance.
• Corrosion allowances and thread depth allowances shall not be less than the minimum values shown in TABLE 10. For threaded-end pipe, the thread depth allowance shown shall be added to the corrosion allowance.
• The minimum wall thickness of piping shall not be less than any of the following:
• The thickness required for pressure plus corrosion allowance, and thread depth allowance, if any.
• The thickness determined from TABLE 11, Column A or B, whichever results in the heavier wall thickness.
• The thickness required by the D/t ratio criterion, see the next paragraph.
• The D/t ratio (nominal diameter/wall thickness minus the corrosion allowance) shall not exceed

150. With the approval of the Owner’s Engineer, a ratio greater than 150 may be used if there is no possibility of forming a vacuum. When vacuum is a normal design condition, ASME B31.3 shall govern the required thickness. An analysis shall consider the following factors:

• Draining
• Blocked pump suction
• Sudden condensation
• Unloading rate versus product vaporization rate
• The existence of a vacuum breaker system
• The minimum wall thickness of pipe nipples shall comply with the values shown in TABLE 12. Note: The use of “close” nipples is strictly prohibited.
• Special Requirements for Restricted Service Piping
• (*)Restricted Service piping per TABLE 2 shall meet all of the requirements of this section, and shall not be used unless specified by the Owner.
• (*)Restricted Service pipe produced to the specifications, grade and type referenced in TABLE 2 shall be used only on a project basis. This pipe shall not be used for maintenance except for clearly defined projects as determined by the Owner’s Engineer.
• (*)When used on a Project basis, the Contractor and/or Owner is responsible for control and removal upon Project completion of all Restricted Service pipe. Procedures for control of restricted service pipe shall be submitted to the Inspector for review and approval prior to onsite delivery.

• Restricted Service pipe per TABLE 2 shall not be added into the Owner’s piping stores because it cannot be distinguished from General Service carbon steel pipe.
• Submerged arc welded pipe produced to API 5L Grade B or API 5L Grade X42 may be used per the following restrictions:
• Category D Fluid Service or Normal Fluid Service per ASME B31.3 provided that the design temperature is less than 400 F. This temperature restriction is required because this pipe is prone to accelerated corrosion in hot oil service.
• The fluid service is not categorized as Aggressive Environmental Service(AES) per EP10-2-1. This restriction is necessary because the pipe is not stress relieved nor purchased to a weld hardness requirement.
• The pressure rating is ASME Class 300 or less.
• API 5L Grade X42 pipe shall have a maximum carbon equivalence (CE) of 0.43 per the supplemental requirement SR18 of API 5L and a maximum yield strength (Sy) of 50,000 psi. Material Test Reports shall be provided to verify the limitations on CE and Sy.
• Helical submerged arc welded (Spiral Wound Pipe) pipe shall only be used in Category D Service.
• Electric resistance welded (ERW) pipe produced to API 5L Grade B, API 5L Grade X42, or ASTM A53 Grade B Type E may be used per the following restrictions.
• Category D Fluid Service or Normal Fluid Service per ASME B31.3 provided that the design temperature is less than 400 F. The temperature restriction is required because this pipe is prone to accelerated corrosion in hot oil service.
• The fluid service is not categorized as Aggressive Environmental Service (AES) per EP 10-2-1. This restriction is necessary because the pipe is not purchased to a weld hardness requirement.
• The pressure rating is ASME Class 300 or less.
• API 5L Grade X42 pipe shall have a maximum carbon equivalence (CE) of 0.43 per the supplemental requirement SR18 of API 5L and a maximum yield strength (Sy) of 50,000 psi. Material Test Reports shall be provided to verify the limitations on CE and Sy.
• The use of this pipe in water service or other services containing water must be evaluated on a case-by-case basis because preferential corrosion along the weld seam has been reported. This corrosion is caused by the galvanic attack of ferrite bands formed during the welding process which align with the longitudinal weld seam of the pipe. Concern for this type of corrosion can be eliminated if the pipe is welded in an inert atmosphere. Engineering Services should be consulted for specific recommendations.
• Pipe produced to ASTM A 671 and ASTM A 672, Classes 13,23, and 33 (see TABLE 2 for Grade) shall only be used in Category D Service.
• Electric-Fusion welded steel pipe produced to ASTM A139 shall only be used in Category D Services.

PIPING JOINTS

• General Requirements

All piping joints shall be designed, inspected, tested and fabricated in accordance with EP 5-5-1, EP 5-5-3 and ASME B31.3 or ASME B31.1, as applicable.

• Welded Joints
• All welding of piping components shall be per EP 5-5-1 and EP 5-5-2.
• Requirements for weld joint design are covered in EP 5-5-1. In general, for welded piping larger than NPS 2 butt welded construction shall be used. For NPS 2 and smaller, socket welding construction shall be used rather than buttwelding except:
• Where stress or crevice corrosion is expected.
• In Classes 900, 1500, and 2500 where fatigue failure could occur because of vibration and where appreciable and frequent temperature cycles will be experienced. (Examples: T > 500F and N > 50 cycles/year, respectively).
• (*)Threaded piping shall not be substituted for socket-welded piping except for specific services approved by the Owner’s Engineer, see paragraph 7.3. Seal-welding requirements for threaded joints shall be per EP 5-5-3.
• Socket welds for end connections in valves (NPS 2 and smaller) of low chrome alloys (up to and including 9 Cr) may be field stress relieved only if so stated by the Manufacturer. This shall be established before the order is placed. Alternatively, to prevent seat damage, valves should be purchased with 6 inch long nipples (stubs) welded into the valve and stress relieved by the valve manufacturer.
• The use of brazed and braze-welded joints are prohibited.
• Threaded Joints
• (*)Unless otherwise approved by the Owner’s Engineer, threaded joints shall only be used in the following applications:
• Threaded joints shall be used for galvanized piping, NPS 4 and smaller.
• Threaded joints may be used for permanent NPS 2 and smaller piping in Category D Service.
• Threaded valves and fittings may be used where NPS 2 and smaller joints must be disconnected. Examples are plugs in vents, drains, and cleanouts; connections to equipment and instruments; thermal relief valves; and the first block valve downstream of instrument taps.
• Requirements for threaded joints in Hydrofluoric Acid (HF) Service for Phillips HF Units and UOP HF Units are covered in EP 5-10-1 and EP 5-10-2, respectively.
• Threaded joints may be used in Oil Mist Lubrication systems, see EP 6-9-3.
• Threaded joints should be avoided in any service where crevice corrosion, severe erosion, or cyclic loading occur.
• Seal welding requirements for threaded joints are stipulated in EP 5-5-3.

• Flanged Joints
• Requirements for flanges, bolting and gaskets are stipulated in EP 5-2-2.
• Materials for flanges shall be per TABLE 1 in this Practice. The flange material shall be the same as the piping material to which it is attached. Materials for bolting and gaskets shall be in accordance with EP 5-2-2.
• Steel line blanks shall be per ASME B16.48 except that the blank thickness shall be based on ASME B31.3, and shall include the actual specified line corrosion allowance.
• Above ground cast iron pipe shall have flanged joints, either cast integral with the pipe or threaded carbon steel flanges.
• Underground ductile iron pipe with bell and spigot joints may be made up with rubber rings. Rings shall be per ASTM D 1869, synthetic rubber, oil-resistant type.
• Requirements for proprietary flange connectors are stipulated in paragraph 7.6.
• Unions
• The use of pipe unions shall be governed by the following:
• Unions shall not be used above ASME/ANSI Class 150.
• Unions shall not be used in Severe Cyclic or Category M Service.
• The maximum permissible size for unions is NPS 1-1/2 for non-Category D Service.
• The maximum permissible size for unions is NPS 3 for Category D Service.
• The use of pipe unions between process vessels, lines, or other equipment and the first block valve is prohibited.
• Unions shall be Class 3000 per MSS SP-83.
• Gasketed unions may be used in NPS 3 and smaller sizes, subject to the requirements of the previous paragraph.
• Proprietary Joints
• (*)All proprietary and special pipe joints shall be approved by the Owner’s Engineer prior to use.
• Proprietary joints such as Grayloc connectors of REFLANGE E-CON or G-CON connectors may be considered as alternatives to ASME/ANSI B16.5 flanges for Classes 600 and higher.

TUBING

• General Requirements
• Selection of tubing materials shall be per TABLE 9. All tubing shall be seamless.
• (*)Tube shall be furnished with square cut ends unless otherwise specified by the Purchaser.
• (*)Tube shall be furnished to the specific or random lengths as specified by the Purchaser.
• Size Limitations
• Tubing shall not be used in sizes larger than 2 inch outside diameter. Note: For tubing sizes larger than 1 inch, the ferrules must be pre-swaged through the use of a hydraulic swaging unit.

• Corrosion Allowance And Wall Thickness
• The wall thickness of tubing shall not be less than that required by ASME B31.3 or ASME B31.1, as applicable. The design conditions used to compute the wall thickness shall be established using EP 5-1-1.
• No corrosion allowance is required for tubing. Materials shall be selected such that anticipated corrosion during the tubing’s service life does not exceed 10 mils.
• The minimum wall thickness of tubing shall not be less than any of the following:
• The thickness required for pressure.
• The thickness shown in TABLE 13.

TUBING JOINTS

• General Requirements

All tubing joints shall be designed, inspected, tested and fabricated and assembled in accordance with EP 5-5-1, EP 5-5-3 and ASME B31.3 or ASME B31.1, as applicable.

• Proprietary Joints

(*)All proprietary and special tube joints shall be approved by the Owner’s Engineer prior to use.

• Bite-Type Compression Fittings
• (*)Joints with flared, flareless, or compression bite-type tubing fittings shall not be used in severe cyclic conditions without prior approval from the Owner’s Engineer.
• (*)Bite-type compression fittings shall be used with tubing. Compression fittings shall be per TABLE 14. Component parts of these fittings shall not be interchanged between manufacturers’ models. These joints are limited to 375 F and 150 psig if made of brass, to 375F and 1000 psig if made of carbon steel, and to 1200 F and 3100 psig if made of AISI Type 304, 316 stainless steel or Alloy 20 (N08020). Derating factors per the manufacturer shall be used based on design temperature. Higher pressures and temperatures are permitted with submittal of ASME/ANSI B31.3 Code calculations and approval of the Owner’s Engineer.

VALVES

• Requirements for valve selection and design are stipulated in EP 5-3-1.
• Materials for valve bodies shall be per TABLE 1. Valve trim materials and other material requirements are specified in EP 5-3-1.

FITTINGS

• General Requirements
• Fittings, including bends and branch connections, shall be in accordance with EP 5-1-1, ASME B31.3 or ASME B31.1, as applicable, and the additional requirements of this Practice.
• Materials for all fittings shall be per TABLE 1. All fitting materials shall be of the same nominal composition as the pipe to which they are attached.

• Fittings shall be per TABLE 15 and the additional requirements of this Practice. Unless otherwise specified by the Purchaser, fittings shall be furnished to match the pressure rating, size and wall thickness of the attached pipe.
• The use of cast steel buttwelding fittings conforming to ANSI/ASME B16.9 is prohibited.
• The use of cast steel fittings conforming to ASME/ANSI B16.5 is prohibited.
• (*)The use of welded construction in the fabrication of fittings conforming to ANSI/ASME B16.9 is subject to the approval of the Owner’s Engineer. If welded construction is used to fabricate an ANSI/ASME B16.9 fitting, the Manufacturer shall ensure that all welded seams have a joint efficiency of 1.0 as defined ASME B31.3.
• Austenitic stainless steel used for corrosive service shall be the extra low carbon or stabilized grades: AISI Types304L, 316L, 321 or 347. The use of Grades 304L and 316L are limited to a maximum design temperature of 800 F.
• Pipe nipples shall be of the same material as the piping to which they are attached.
• Branch Connections

The selection and fabrication requirements for piping branch connections shall be per the requirements of EP 5-5-1.

• Bends And Mitered Bends
• Butt welding elbows shall be long radius, unless short-radius elbows are required and specified on drawings.
• To avoid excessive stiffness for piping flexibility, a maximum thickness limit of 30% above nominal shall be specified for elbows in sizes greater than NPS 12.
• (*)Pipe bends shall be limited to use in lines handling solids, certain pigged lines, and other applications with special requirements. They shall not be used for general piping where weld fittings can be used unless approved by the Owner’s Engineer. When bends are used, an increased wall thickness may be required to satisfy the intended service. When used, pipe bends shall comply with the following:
• Either seamless or welded pipe may be formed into bends, except the furnace buttwelded type.
• Centerline radius of pipe bends shall be equal to at least 5 times the nominal pipe diameter.
• Miter bends may be used when more economical than welding elbows for the following services:
• Water piping
• Drain lines
• (*)Internal piping in pressure vessels when approved by Owner’s Engineer.
• (*)Other services subject to the approval of the Owner’s Engineer.
• Fabrication requirements for pipe bends and miter bends are specified in EP 5-5-1.

• Reducers, Pipe Caps And Plugs
• Buttwelding and socket-welding reducers and swaged nipples shall be preferred to flanged reducers for reductions in run. Swaged nipples shall be used when a reduction in size is made at threaded equipment.
• Long-radius buttwelding reducing elbows made in accordance with ANSI/ASME B16.9 shall be considered for line reductions at end suction pumps.
• In threaded pipe, reducing nipples shall be used; the use of bushings is prohibited. Socketwelding reducer inserts shall be used in socket-welded piping (NPS 2 and smaller) for reductions of two or more pipe sizes.
• Welding caps are preferred for closures in welded piping, except that bolted flanged covers shall be used where access is needed (for example, for cleaning, inspection, or a future tie-in). In sizes for which welding caps are not commercially available, closure shall be made by means of ellipsoidal heads.
• Threaded plugs shall be fabricated from solid barstock.

SPECIAL COMPONENTS

• (*)The use of piping components designed in accordance with 304.7.2, A304.7.2, or A304.7.3 of ASME B31.3, rather than listed Component Standards, requires prior approval from the Owner’s Engineer. Exceptions to this requirement would be any of the commonly used steam traps (such as Armstrong or Sarco-Spirax) and strainers (such as Mueller).
• The materials used in special components, such as steam traps, strainers, separators, and filters, shall conform to the manufacturer’s standards and the requirements of Section 5.0.
• Metal and Fabric Expansion joints shall be designed to comply with the requirements of EP 5-4-1 and EP 5-4-2, respectively.

13.0 TABLES

TABLE 1

MATERIAL SELECTION FOR METALLIC PIPING COMPONENTS

NOTES:

• Selection of materials not listed are subject to the approval of the Owner’s Engineer.
• Material selection tables are included in this Practice.

TABLE 2

PIPING MATERIAL SELECTION FOR CARBON STEEL

NOTES:

• Fittings containing butt welds shall be spot radiographed per ASME B31.3 for Category D Service. For all other fluid services, 100% radiography per EP 5-5-1 is required.
• See ASME B31.3 regarding limitations for Severe Cyclic Service.
• Straight or helical seam submerged arc welded piping only.
• (*)A671 Grades CC60, CC65 and CC70 Class 12 maybe used in non-AES services with Owner’s Engineer Approval.

TABLE 3

PIPING MATERIAL SELECTION FOR LOW ALLOY STEEL

NOTES:

• All welds shall meet the hardness requirements of EP 10-2-3.
• Fittings containing butt welds shall be 100% radiographed per EP 5-5-1.

TABLE 4

PIPING MATERIAL SELECTION FOR AUSTENETIC (CR-NI) ALLOYS

NOTES:

• UNS number are shown within the parenthesis.
• Supplementary requirement S5 in ASTM A312 stipulates full radiography of double-welded longitudinal seams.
• (*)Consult the Owner’s Engineer for selection of weld filler metals.
• Fittings containing butt welds shall be 100% radiographed per EP 5-5-1.

TABLE 5

PIPING MATERIAL SELECTION FOR ALLOY 20

NOTES:

• Supplementary requirement S5 in ASTM A312 stipulates full radiography of the longitudinal seam.
• (*)Consult the Owner’s Engineer for selection of weld filler metals.
• Fittings containing butt welds shall be 100% radiographed per EP 5-5-1.

TABLE 6

PIPING MATERIAL SELECTION FOR MONEL

NOTES:

• Fittings containing butt welds shall be 100% radiographed per EP 5-5-1.
• The supplemental Weldability Test S-2 per ASTM A494/A494M shall be specified.

TABLE 7

PIPING MATERIAL SELECTION FOR INCONEL(ALLOY, 625)

NOTES:

(1) Fittings containing butt welds shall be 100% radiographed per EP 5-5-1.

TABLE 8

PIPING MATERIAL SELECTION FOR INCOLOY (ALLOYS 800, 800H)

NOTE:

(1) Fittings containing butt welds shall be 100% radiographed per EP 5-5-1.

TABLE 9 TUBING MATERIALS

NOTES:

• Tubing shall be seamless
• To be used for steam tracing only, see EP 5-6-8.
• (*)Unless otherwise specified by the Owner’s Engineer, AISI Type 316 stainless steel shall be used for compression fittings.

TABLE 10

MINIMUM CORROSION AND THREAD DEPTH ALLOWANCES (5), (7)

NOTES:

• Includes all steels with an alloy content not exceeding 2-1/4 Cr-1 Mo.
• Includes all steels with an alloy content of 2-1/2 to 9 Cr-1 Mo, and 3-1/2 to 9 Ni steels.
• Includes all steels with an alloy content of 12Cr and greater.
• Includes materials such as Inconel, Incoloy, Hastelloy.
• When a corrosion allowance of 1/16 inch is specified, a minimum value of 0.050 is acceptable.
• Equals a maximum depth of ASME/ANSI B1.20.1 threads.
• (*)The above corrosion allowances are minimum only; corrosion allowances for each line must be obtained from Owner’s Engineer.

TABLE 11

MINIMUM PIPE WALL THICKNESS CRITERIA

NOTES:

• Nominal thickness must be reduced by 12-1/2 percent for mill tolerance.
• Use thickness calculated for pressure plus corrosion allowance plus thread depth allowance.
• This table does not apply to nipples used for branch connections, or to piping for atmospheric vents and drains, see paragraph

6.3.6 and TABLE 12.

TABLE 12

PIPE NIPPLE MINIMUM WALL THICKNESS

NOTES:

• Includes stainless steel if supplied to ASME/ANSI B36.10M.
• Nominal thickness must be reduced by 12-1/2 percent for mill tolerance.

TABLE 13

MINIMUM TUBE WALL THICKNESS CRITERIA

TABLE 14

ACCEPTABLE COMPRESSION FITTINGS FOR TUBING

TABLE 15 FITTING STANDARDS

NOTES:

• Use of cast steel fittings requires approval of Owner’s Engineer.
• Limited to air and water.
• Pipe threads shall be per ASME B1.20.1.

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