031801

Piping Fabrication Shop or Field IP 3-18-1 of 11

(This practice is appropriate for attachment to Inquiry or Purchase Document) Rev. 2 March 1998

THIS INFORMATION FOR AUTHORIZED COMPANY USE ONLY

EXXON RESEARCH AND ENGINEERING COMPANY — FLORHAM PARK, N.J.

INTERNATIONALPRACTICE

SCOPE

I 1.1 This practice covers the fabrication, inspection and testing of piping.

I 1.2 An asterisk ( ✶) indicates that a decision by the purchaser is required or that additional information isspecified by the purchaser.

SUMMARY OF ADDITIONAL REQUIREMENTS

I 2.1 Table 1 lists the practices, codes, and standard which shall be used with this practice.

I ✶ 2.2 Table 2 lists the practices, codes, standards, and specifications, which shall be used with this practice asspecified by the Purchaser.

TABLE 1

PRACTICES

➧IP 18-7-1 Welding ProceduresIP 18-10-1 Additional Requirements for MaterialsIP 20-1-1 Inspection of Equipment and MaterialsIP 20-1-3 Quality Programs

CODES AND STANDARD

ASME CodesSection V Nondestructive ExaminationsSection VIII Pressure Vessels, Division 1B31.3 Process PipingASME StandardB16.25 Buttwelding Ends

TABLE 2

PRACTICES

IP 18-12-1 Positive Material IdentificationIP 19-3-2 Refractory Linings for Pressure Vessels and PipingIP 19-7-1 Protection of Stainless Steel During Fabrication, Shipping, Storage, and Field Construction

CODES, STANDARDS, AND SPEC IFICATIONS

ASME CodesSection I Power BoilersB31.1 Power Piping CodeASME StandardB1.20.1 Pipe Threads, General Purpose (Inch)ANSI / AWS Code and SpecificationsD1.1 Structural Welding Code - SteelA5.XX Series Filler Metal Specifications ASTM StandardE 142 Controlling Quality of Radiographic TestingPFI (Pipe Fabrication Institute) StandardES-24 Pipe Bending Methods, Tolerances, Process and Material Requirements

I ✶ 2.3 Fabrication of all piping shall be performed in accordance with ASME B31.3, ASME B31.1, or ASMESection I as applicable, and the additional requirements of this practice.

I 2.4 When compliance with any code or standard by a local jurisdiction is mandatory, the requirementsprescribed therein shall also be met.

DEFINITIONS

I 3.1 Small piping connections. Any branch connection NPS 2 (50 mm) or less.

Changes shown by ➧

IP 3-18-1 Piping Fabrication Shop or Field of 11

Rev. 2 March 1998 (This practice is appropriate for attachment to Inquiry or Purchase Document)




I 3.2 Dangerous materials, as used herein, includes the following materials:

a. Toxic materials, such as phenol, hydrogen sulfide, chlorine.

b. Highly corrosive materials, such as acids, caustic and other similar materials.

c. Flammable materials (including light hydrocarbons lighter than 68 degrees API).

d. Combustible liquids.

e. Boiler feedwater and steam, in systems requiring ASME Class 300 and higher ratings.

f. Oxygen in concentrations greater than 35%.

I 3.3 Non-dangerous materials, as used herein, include all materials not listed as dangerous in Par. 3.2.

I 3.4 Combustible liquids. High flash liquids [flash points 100°F (38°C) or higher] when handled attemperatures more than 15°F (8°C) below their flash point.

I 3.5 Flammable liquids. Low flash liquids [flash point below 100°F (38°C)]; and high flash liquids [flash point100°F (38°C) or higher] when handled at temperatures above or within 15°F (8°C) of their flash points.

I 3.6 Flammable materials (including light hydrocarbons lighter than 68 degrees API). Flammable liquids;hydrocarbon vapors; and other vapors, such as hydrogen and carbon disulfide, that are readily ignitablewhen released to atmosphere.

I 3.7 Wet H2S is defined as greater than 50 ppm of H2S in the water phase.

I 3.8 The term Inspector, as used herein, refers to the Owner's Representative.

SMALL PIPING DOCUMENTATION

I 4.1 The following information for small piping connections shall be shown on the Engineering Drawings:

a. Specific location and orientation of small piping connections.

b. Connection size and schedule.

c. Valve or fitting type.

d. Designation of connections to be gusseted and specifications to be used for gussets.

e. Special welding requirements.

f. Temporary valves and nipples that are used only during pressure testing shall be indicated on thedrawings.

ATTACHMENT MATERIALS

R ✶ 5.1 Unless otherwise specified, lugs, brackets, insulation supports, or other attachments that must bewelded to piping, shall be of the same nominal chemical composition and physical properties as thepiping component to which they are attached.

BENDS, MITER BENDS, AND ELBOWS

R ✶ 6.1 Pipe bends shall comply with the following requirements:

a. Fabrication shall be in accordance with ES-24 of the Pipe Fabrication Institute .✶ b. The centerline radius of pipe bends shall be equal to at least three times the nominal pipe

diameter. Proposals to use smaller radius pipe bends shall be submitted to the purchaser forapproval by the Owner's Engineer.

R 6.2 Miter bends may be used where the pipe diameter exceeds NPS 12 (300 mm) and shall comply with thefollowing:

a. Bends exceeding 45 degrees shall be at least 3-piece (2 miter cuts), with not less than 4 times thepipe wall thickness between the centerlines of the welds at the crotch, or 1 in. (25 mm), whichever isgreater.

b. Bends shall have a centerline radius at least equal to the nominal pipe size.

c. The maximum miter angle (half the change of directions) shall be 22-1/2 degrees up to 200 psig(1380 kPa) design pressure, 15 degrees up to 400 psig (2760 kPa), and 11-1/4 degrees over 400 psig(2760 kPa).

R ✶ 6.3 Butt welding elbows shall be of the long radius type unless otherwise approved by the Owner'sEngineer.

Pipi ng Fabricatio n Shop o r Field IP 3-18-1 of 11





DIMENSIONAL TOLERANCES

R 7.1 Tolerances for finished fabricated p iping shall conform to Figure 1.

LOCATION OF CONNECTIONS

O ✶ 8.1 All take-off connec tions for s team, instrument air, fuel gas and o ther gases con taining moistureshall be from the top of the supp ly header.

O ✶ 8.2 Condensa te line connec tions into condensate return headers shall be at the top of the heade r.

BRANCH CONNECTIONS LARGER THAN NPS 2 (50 mm)

R ✶ 9.1 Integrall y reinforced branch welding fitti ngs which abut the outside surface of the run wall, in sizesNPS 4 (100 mm) and larger, are not pe rmitted under an y of the following cond itions, unless approvedby the Owner's Engineer:

a. The d/D ratio (branch diameter/run diameter) exceeds 0.8.

b. The run piping wall thickness is less than standard schedule.

c. The run piping wall thickness is less than 0.75 in. (19 mm) where outside diameter exceeds 36 in.(900 mm).

R 9.2 Pad reinforced b ranch connec tions are not permitted whenever the piping design temperature is 800°F(427°C) or greater.

R 9.3 If pad-type re inforce ment is used for full s ize branch connec tions, it shall be of the complete-encirclement type.

R 9.4 Fabricated branch connec tions. Reinforcing pads (when required) shall be added as a subsequentfabrication step after v isual inspec tion of the branch -to-header weld, and shall be provided with aminimum 1/8 in. (3 mm) drill ed vent hole in each separa te pad sec tion.

SMALL PIPING CONNECTIONS

R 10.1 The minimum wall thickness of nipples that are used for branch connec tions NPS 2 (50 mm ) orsmaller shall be as follows:

MATERIAL ≤≤≤≤ NPS 1-1/2 (40 mm) NPS 2 (50 mm)

Carbon and low alloy steel 160 80

Stainless and other high alloy steel 80S 40S

R 10.2 Nipples that are threaded over their entire length shall not be used.

S ✶ 10.3 Vibrating serv ice or dangerous materials serv ice. A block va lve shall be provided for the purpose ofiso lating all p iping connec tions NP S ≤≤≤≤ 1-1/2 (40 mm ) to main headers of an y size.

R ✶ 10.4 When a valve is provided for the purpose of iso lating p iping connec tions ≤≤≤≤ NPS 1-1/2 (40 mm ), theoutlet of the valve shall be located within 9 in. (225 mm ) of the branch connec tion, measured along thebranch pipe axis. In cases where adhering to the 9 in. (225 mm) dimension (pipe wall to valve outlet) isnot practicable, such deviations shall be approved by the Owner's Engineer.

BRACING

S,R 10.5 Piping connec tions NP S ≤≤≤≤ 1-1/2 (40 mm ) shall be braced for the following applications:✶ a. For both vibrating and non -vibrating se rvices, bracing is required for piping connections ≤ NPS

1-1/2 (40 mm) that are fabricated using a nipple welded d irectly to the run p ipe, except forCategory D fluid services.

b. Bracing is not required for small piping connections in any serv ice that connect to p ipe of thesame size or one s ize larger.






SMALL PIPING CONNECTIONS (Cont)

c. Categories of equipment in vibrating service requiring bracing of piping connections, and theextent of bracing, shall be per the following:

PRIMARY EQUIPMENTOR

SERVICE CATEGORYThe first nipple and valve shall be braced for: (1) (2)

Reciprocating Compressors Connections to interstage, upstream, and downstream pipingand equipment associated with reciprocating compressors(Includes first major piece of equipment upstream anddownstream of compressor).

✶

Centrifugal Compressors Connections to centrifugal compressor piping within the greaterof 20 ft (6 m) or 20 pipe diameters, measured along the pipeaxis, from the equipment nozzle.

Design of all connections to compressor piping equal to orgreater than NPS 36 (900 mm) diameter shall be submitted tothe purchaser for approval by the Owner's Engineer.

Reciprocating Pumps Connections to suction and discharge piping and equipment forreciprocating pumps. (Includes first major equipment upstreamand downstream of pump.)

Centrifugal Pumps and Rotary Pumps Connections to pump piping within the greater of 20 ft (6 m) or20 pipe diameters, measured along the pipe axis, from theequipment nozzle.

Centrifuges Connections to centrifuge piping within the greater of 20 ft(6 m) or 20 pipe diameters, measured along the pipe axis, fromthe equipment nozzle.

Machinery where rotating orreciprocating component speed range is60 to 1000 rpm (1 to 17 rev/s)

Connections to all piping connected to or supported from anytype of rotating equipment or its supporting structure. (Includesfirst major piece of equipment upstream and downstream ofmachine.)

Piping or Equipment subject to ProcessInduced Vibration

Connections to piping or equipment subject to process inducedvibration (e.g., fluid solids units, lines in two phase flow,hydraulic shock from rapid valve operation, high pressureletdown systems.)

Pressure Relieving (PR) Devices Connections to PR device inlet and discharge piping within 20ft (6 m) or 20 pipe diameters, measured along the pipe axis,from the PR device.

Notes:✶ (1) Bracing of connections on the primary equipment or major piece of equipment as described herein will

be done by the equipment supplier or purchaser, as specified.✶ (2) Unless specified, bracing of integrally reinforced extended body valves or integrally reinforced

extended fittings with valves is not required for:(a) Connections which terminate at the valve or continue as tubing, if the valve outlet is located

within 9 in. (225 mm) of the connection.(b) Indicating pressure gage connections if the outlet of the valve is within 9 in. (225 mm) of the

connection.

S,R 10.6 Bracing design shall be as follows:

a. Material for welded gussets shall be of the same nominal chemical composition as the connectedparts except that carbon steel may be used for gusseting P-1, P-3, P-4, and P-5 materials.






SMALL PIPING CONNECTIONS (Cont)✶ b. Unless otherwise specified, connections shall be braced in two planes with gussets having a

minimum thickness of 3/16 in. (5 mm) and a minimum width of 3/4 in. (19 mm), as shown below:

��

031801

General Note:Bracing Detail applicable toextended Body Type Valve,or Compact Body Valve plusNipple (as illustrated).

Pipe WallTwo PlaneGusset ing

9 in. max.(225 mm)

1/2 in.(12 mm) max.

✶ c. In cases where PWHT of structural attachment welds to a pressure boundary is required, gussetstubs (or pads) may be welded to the component prior to PWHT, and then may be used to permitlater gusset-to-stub (or pad) attachment wit hout PWHT. Proposals to use special weldingprocedures in lieu of PWHT shall be submitted to the purchaser for approval by the Owner'sEngineer.

✶ d. Proposals to use clamped or bolted gusset designs shall be submitted to the purchaser forapproval by the Owner's Engineer.

R ✶ 10.7 Bracing design for piping connections NPS ≤≤≤≤ 1-1/2 (40 mm) requiring double block valves shall besubmitted to the Purchaser for approval by the Owner's Engineer.

R ✶ 10.8 Unless otherwise specified, all small piping connections in services that are ASME Class 900 andabove shall be braced. The bracing design shall be submitted to the Purchaser for approval by theOwner's Engineer.

SEAL WELDING THREADED CONNECTIONS

S,R 11.1 All threaded piping connections shall be seal welded except seal welding is not necessary for thefollowing:

a. Category D fluid services as defined in ASME B31.3.✶ b. Instruments or piping components that require periodic removal for maintenance.

c. Union ring threads.d. Thermowells.

✶ e. Plugs and caps for drain and vent valves. Plugs and caps for drain and vent valves that are usedonly for hydrostatic testing and are in dangerous materials service shall be seal welded.

✶ f. Miscellaneous other connections identified by the Owner's Engineer.

R 11.2 If piping assemblies w ill be PWHT, seal welding shall be given the necessary heat treatment as well.However P-1, P-3, P-4, P-5A and P-9 materials may be seal welded without subsequent PWHTprovided all of the following requirements are met:a. The minimum preheat meets either the “required" or the “recommended" preheat listed in ASME

B31.3.b. A temper beading technique is employed for all materials except P-1.c. Low hydrogen electrodes or welding processes are used.d. For all alloy steels, either low carbon electrodes with matching chemistry (i.e., E8018-B2L) or high

nickel electrodes (i.e., ENiCrFe-3) are selected.






R 11.3 Connections requiring seal welding shall be made up without the use of sealing compound orPTFE tape. All cutting oil shall be removed prior to assembly. After the joint has been tightened to fullthread engagement, seal welding shall cover all exposed threads, and a minimum of two weld passes arerequired.

VALVES, FLANGES, AND JOINTS

R 12.1 Welding is not permitted on valves that are equipped with soft seats, unless the seats have beenremoved or precautions that are recommended by the valve manufacturer have been taken to preventdamage to the soft seats.

R 12.2 Taper pipe threads (NPT) per ASME B1.20.1 shall be used for all threaded pipe joints, includingthermowell nozzles.

R 12.3 Slip-on flanges shall be positioned so that the distance from the face of the flange to the pipe end shallbe equal to the nominal pipe wall thickness, plus 1/8 in. (3 mm).

M 12.4 Flange bolt holes shall straddle the established centerlines (horizontal, vertical, or layout centerlines),except when required for matching orientation at equipment flanges.

R 12.5 Stub-ends for lap-joint flanges, if fabricated by welding, shall be made with complete penetration welds.S 12.6 Pipe unions between process vessels, lines, or equipment and the first block valve are prohibited.R ✶ 12.7 The use of proprietary type piping joints shall be approved by the Owner's Engineer.R ✶ 12.8 Drip rings shall not be used unless approved by the Owner's Engineer.

WELDING JOINTS

R ✶ 13.1 Welding end preparation. Unless otherwise required by the piping material or welding processes to beused, welding ends shall be prepared per ASME B16.25.

R 13.2 Radial misalignment at the joining ends of piping components shall be limited to 1/8 in. (3 mm) or 1/4of the pipe wall thickness, whichever is less. Internal radial misalignment exceeding 1/16 in. (1.5 mm)shall be taper trimmed so that the adjoining internal surfaces are flush; however, the resulting thickness ofthe welded joint shall not be less than the minimum design thickness plus corrosion allowance.

R 13.3 Minimum spacing of girth butt welds. The clear distance between the edges of adjacent girth butt weldsshall not be less than four times the pipe wall thickness, or 1 in. (25 mm), whichever is greater.

R ✶ 13.4 Minimum spacing of branch connections. The clear distance between the edges of attachment weldsfor adjacent branch connections shall not be less than four times the thickness of the run wall, or 1 in. (25mm), whichever is greater. Deviations from this spacing requirement shall be approved by the Owner'sEngineer.

M 13.5 Backing rings may be used only for the following applications:

a. For piping under the jurisdiction of the ASME Code Section I.✶ b. For piping in clean steam and air service.

c. For castable lined pipe.✶ d. Other applications when approved by the Owner's Engineer.

R 13.6 Backing rings, when used, shall be fused into the joint for the entire circumference.

M ✶ 13.7 Backing rings are prohibited for the following applications:

a. “Pigged" lines.

b. Auxiliary piping for machinery, including (but not limited to) piping systems such as jacket coolingwater, fuel, lube oil, seal oil, instrument and starting air servicing compressors, turbines, engines, andgears.

c. Intake and interstage piping for reciprocating, and rotary screw compressors.

I 13.8 Consumable inserts are not classified as backing rings, and may thus be used for all applications.

ADDITIONAL REQUIREMENTS FOR CEMENT-LINED CARBON STEEL PIPE AND FITTINGS

M 13.9 For pipe diameters < NPS 24 (600 mm) the welding arc shall not come into direct contact with thecement lining. This shall be accomplished by the use of partial penetration welding or backing rings. Toinsure that a sufficient amount of weld metal is deposited for the integrity of the joint while still maintainingpartial penetration, a mockup test together with joint and welding details shall be submitted to the Inspectorfor approval prior to production welding.






R 13.10 For pipe diameters NPS ≥≥≥≥ 24 (600 mm) the lining shall be cut back 2 to 4 in. (50 to 100 mm) from theend prior to welding to permit full penetration welding, with or without backing rings. This area shall bemanually cement lined after welding is completed.

M 13.11 The cement-lined joints shall be made up using any of the following procedures:

a. Butted joints. The root faces of the adjoining pipe walls shall be tightly butted (no gap for welding),and the ends of the cement linings shall be smooth and flush with the ends of the root faces. Nocoating or gasketing of the cement lining faces shall be done.

b. Sodium silicate coated, gasketed joint. Both ends of the lining shall be coated and a 1/16 in. (1.6mm) gasket installed between the facings of the lining. The gasket shall not extend between the endsof the pipe walls.

c. Epoxy cement coated joint. A uniformly applied layer of epoxy cement, approximately 1/16 in. thick,shall be applied to both ends of the cement lining. Initial set of the epoxy cement must take placebefore welding.

R 13.12 Alternative welding procedures for butt joints. For cement lined carbon steel pipe welding, weldingprocedure specifications and performance qualifications per ANSI/AWS D1.1 is an acceptable alternativeto ASME B31.3 requirements.

HEAT TREATMENT

R ✶ 14.1 When PWHT is required, it shall be done in an enclosed furnace or by electrical resistance heatingmethods. The use of other methods to perform PWHT shall be approved by the Owner's Engineer.

S,R ✶ 14.2 PWHT is required for all welds in carbon steel piping in wet H 2S service, except as specificallyexempted in a. through d. below. The PWHT procedure outlined in ASME B31.3, Par. 331.1 shall befollowed; however, the exceptions provided in Table 331.1.1, based on nominal wall thickness, are notpermitted. The minimum PWHT temperature shall be per ASME B31.3 for the material used, but notless than 1150°F (620°C).

The specific types of welds listed in a. through d. below are exempt from the special PWHT requirementsof this paragraph. However, this does not exempt these welds from PWHT which is required by ASMEB31.3, or other applicable requirements.

a. Multipass girth welds in seamless piping, welded from the outside surface only.

b. External attachment welds, when the weld metal is not in contact with wet H2S.

c. Multipass seal and socket welds.

d. Multipass welds for set on branch connections (e.g., see ASME B31.3, Figure 328.4.4 (a)), providedall welding is performed from the outside.

R ✶ 14.3 PWHT for piping handling alkaline solutions shall be governed by the following:

a. The postweld heat treatment procedure outlined in ASME B31.3, par. 331.3, shall be followed. Theexemptions provided in Table 331.3.1 based on nominal wall thickness are not permitted. Socketwelded and seal welded threaded connections for all pipe sizes shall also be postweld heat treated.The minimum holding time at the full postweld heat treatment temperature shall be 1 hour.

b. Attachment of clips, brackets, or other devices requiring welding directly to the inside or outsideof vessel or piping walls after postweld heat treatment is not permitted unless the heat treatment isrepeated on the equipment or material after welding.

R ✶ 14.4 Dissimilar materials. Any heat treatment proposed for joints involving dissimilar materials shall beapproved by the Owner's Engineer.

R ✶ 14.5 Materials not covered by ASME B31.3. Heat treatment requirements for welded joints or bends ofmaterials not covered by ASME B31.3 shall be submitted to the purchaser for approval by the Owner'sEngineer.

R 14.6 Exposed machined and threaded surfaces shall be protected from oxidation during heat treatment.

R ✶ 14.7 Proposals to weld or heat piping, after final heat treatment, shall be submitted to the purchaser forapproval by the Owner's Engineer.






INSPECTION AND TESTING

R 15.1 All final inspection and testing shall be performed after any required postweld heat treatment. However,radiographic examination may be performed prior to postweld heat treatment provided:

a. Such action does not conflict with the applicable code(s) or regulation(s) and

b. If any materials other that carbon steel (P-1) are involved, the final weld area will be dye penetrant ormagnetic particle inspected after postweld heat treatment.

R 15.2 Inspection, examination and testing of all piping shall be per ASME B31.3, except as modified in thispractice.

RADIOGRAPHIC EXAMINATION

R 15.3 The minimum required radiographic inspection for girth-butt and miter bend welds, and branchconnection welds that are suitable for radiography, shall be per ASME B31.3 and the followingrequirements:

MATERIAL (1) % SHOP WELDS (2) % FIELD WELDS (2)

Carbon Steel (P-1) 5 5

Low Alloy Steel (P-3, P-4, P-5, and P-9) 20 (3) 50 (3)(4)

Stainless Steels and Nickel Alloys (P-8 & P-4X) 20 (3) 20 (3)

Aluminum Alloys (P-2X) 10 20 (4)

Notes:(1) For materials that are not listed, the radiographic requirements and acceptance criteria will be specified by the

Owner's Engineer.(2) The first weld for each WPS and each position for each welder shall be radiographed. The percent of specified

radiography shall apply to each P-Number and welding process.✶ (3) If approved by the Owner's Inspector, once the minimum radiography requirements per ASME B31.3 and Note 2

have been met, any additional radiography may be met by the random spot radiography method.(4) The field weld radiography percentage may be reduced to the shop weld percentage if the welders are qualified

per AWS QC7-93 Supplement F.

R 15.4 Progressive sampling (tracer examination) , as required by ASME B31.3 , shall be in addition to theminimum required radiographic inspection.

R ✶ 15.5 Radiographic acceptance criteria shall be in accordance with ASME B31.3 for normal fluid service unlesssevere cyclic service is specified.

R 15.6 All bimetallic welds (ferritic to non-ferritic) shall be 100% radiographed.

R 15.7 Spot Radiography, when permitted, shall be in accordance with the following:

NOMINAL PIPE SIZE (NPS)in. mm

MINIMUM NUMBER OFSPOT RADIOGRAPHS

≤ 18 ≤ 450 1

20 - 36 500 - 900 2

≥ 36 ≥ 900 3

R ✶ 15.8 The length of film for each spot radiograph shall be ten (10) in. (250 mm) or half the pipecircumference, whichever is less.

S 15.9 For girth-butt, miter, and longitudinal welds in piping which is to be pneumatically field tested.

a. Inspection shall meet the acceptance criteria specified by ASME B31.3 for Severe CyclicConditions .

b. All welded longitudinal joints which have not been previously hydrotested or radiographedshall be radiographed along the entire length of the weld. Ultrasonic examination or eddy currentexamination may be substituted for radiography.

✶ c. All field girth-butt and miter welds shall be 100 percent radiographed unless otherwise specified.Welds that cannot be radiographed shall be inspected by the liquid penetrant or magnetic particlemethod.






I 15.10 Wire type image quality indicators (IQIs) equal to those meeting EN462-1, DIN 54109, or JIS-Z3104requirements may be substituted for those specified in ASME Section V provided an equivalent sensitivityis met.

R 15.11 A minimum of 5 percent of all socket welds shall be radiographed to inspect for the presence of a gapafter welding and for weld defects such as lack of penetration.

VISUAL EXAMINATION

M 15.12 Maximum allowable projections of weld metal into the pipe bore at welded butt joints shall be perASME B31.3 and the following:

✶ a. The maximum internal projection shall be 1/16 in. (1.5 mm) for piping NPS 2 (50 mm) and smallerand for “pigged" lines.

b. All internal welds shall be smooth and flush with the internal diameter of the pipe in the followingapplications:

1. Plastic or elastomeric lined pipe

2. Orifice flanges and “meter tubes"

3. Intake and interstage piping for reciprocating and rotary screw compressors.

R 15.13 Undercutting of welds in intake, recycle, interstage, and start-up bypass piping for reciprocating androtary screw compressors is not permitted.

ULTRASONIC EXAMINATION

R ✶ 15.14 Ultrasonic examination may be substituted for radiographic examination when approved by theOwner's Inspector.

R 15.15 All welds, where the pipe wall thickness exceeds 1-1/4 in. (32 mm), shall be 100 percentultrasonically examined in lieu of radiographic examination when a single wall radiographic techniquecannot be used.

R 15.16 Branch connection welds, not suitable for radiography, shall be ultrasonically examined to the samepercentages that are specified for radiographic examination. In-process magnetic particle examination orin-process liquid penetrant examination may be substituted for ultrasonic examination where the branchdiameter does not exceed 50% of the run diameter and for all integrally reinforced branch connectionswhen the ID can be visually examined.

R 15.17 When ultrasonic examination is substituted for spot radiography, the length of the weld joint spot shallbe 10 in. (250 mm) or half the pipe circumference, whichever is less.

MAGNETIC PARTICLE EXAMINATION

R ✶ 15.18 For non-magnetic materials, and if approved by the Owner's Engineer for magnetic materials, liquidpenetrant examination may be substituted for magnetic particle examination.

R 15.19 The D-C prod method shall not be used for P-3, P-4, P-5, and P-9 materials.

R ✶ 15.20 In-process magnetic particle examination . When magnetic particle examination is substituted forultrasonic examination, the root pass, intermediate passes (if specified by the Owner's Engineer), and thefinal pass shall each be examined by the magnetic particle method.

R 15.21 All double welded joints in magnetic materials shall be magnetic particle examined prior to backwelding.

R 15.22 All fillet welded c onnections (magnetic materials only), such as socket welds, seal welds, and slip-onflange welds, shall be inspected as follows:

a. Five (5) percent of carbon steel, P-1, welds shall be examined.

b. Ten (10) percent of magnetic materials, other than carbon steel (e.g., P-3, P-4, P-5, P-9, etc.), shallbe examined.

LIQUID PENETRANT EXAMINATION

R ✶ 15.23 In-process liquid penetrant examination. When liquid penetrant examination is substituted for ultrasonicexamination, the root pass, intermediate passes (if specified by the Owner's Engineer), and the final passshall be examined by the liquid penetrant method.






R 15.24 All double welded joints in non-magnetic materials shall be liquid penetrant examined prior to backwelding.

R 15.25 Ten (10) percent of all fillet welds (non-magnetic materials only), such as socket welds, seal welds, andwelds for slip-on flanges, plus one weld from each forging heat, shall be examined by the liquid penetrantmethod.

SHOP PRESSURE TESTING

C ✶ 15.26 Hydrostatic testing of individual sections of shop fabricated piping systems is not required, exceptas may be specified. If specified, the test shall be per ASME B31.3.

R ✶ 15.27 Piping that is to be internally coated shall be hydrostatically tested prior to installation of the coating,unless otherwise approved by the Owner's Engineer.

SHIPMENT AND STORAGE

PREPARATION FOR SHIPMENT

R 16.1 Protection of openings. After completion of inspection, all shop fabricated piping (i.e., piping notfabricated at the job site) shall be prepared for shipment as follows:

a. Beveled ends and flange gasket surfaces shall be protected from mechanical damage over theirentire surface by firmly attached covers.

b. Threaded-end or socket welding-end connections shall be fitted with metal, wood, or plastic, plugsor caps.

R 16.2 Machined or threaded exterior surfaces of carbon steel, and ferrous alloys with a nominalchemistry of 12Cr and below, shall be protected from corrosion during shipment and subsequentstorage by coating with a rust preventive of a type: (1) to provide protection during outdoor storage for aperiod of twelve months exposed to a normal industrial environment, and (2) to be removable with mineralspirits or any Stoddard solvent.

STORAGE

R ✶ 16.3 Storage of austenitic stainless steel piping shall be as follows:

a. Piping shall be stored under cover and out of contact with the ground.

b. Openings shall be blanked to prevent the entry of moisture.

c. Exposure to salt water, salt spray, or other chlorides shall be prevented.

Revision Memo9/68 Original Issue of Basic Practice6/69 Revision 1 1/82 Revision 76/70 Revision 2 1/84 Revision 86/71 Revision 3 1/86 Revision 91/73 Revision 4 3/90 Revision 106/76 Revision 5 12/90 Revision 116/78 Revision 6

6/95 Revision 0 - Original Issue of International Practice6/97 Revision 13/98 Revision 2

Hardness requirements (old Par. 5.26-5.29) moved to IP 18-10-1. IP 18-6-1 impact requirements (listed in Table 2 )moved to IP 18-10-1. Requirements for hydrostatic test water quality (old Par. 15.32) moved to IP 18-10-1.

Exxon Research and Engineering Company, 1997, 1998






FIGURE 1DIMENSIONAL TOLERANCES

1

1

3

4

51 1 1 1

0 3 1 8 0 1 F 1

2

ITEM NORMAL SERVICE

SPECIAL SERVICES

a. Design Temperature

≥ 850°F or Flange Rating ≥ASME Class 900

b. Where plastic or elastomeric liner(lapped over the flange faces)provides the gasket for the joint.

c. Piping over NPS 3 to be connectedto rotating machinery.

➀ ± 1/8 in. max. from indicated dimensions for face to face, centerto face, location of attachments, etc.

➁ Bend flattening tolerance shall be in accordance with theapplicable Code.

➂ ± 1/8 in. max. lateraltranslation ofbranches orconnections.

± 1/16 in. max. lateral translation ofbranches or connections.

➃ ± 1/16 in. max. rotation of flanges from the indicated position,measured as shown.

± 1/64 in. for piping over NPS 3 to be connected to rotatingmachinery.

➄ Per the applicableCode.

± 1/64 in. max. out of alignment offlanges from the indicated position,measured across any diameter.

Acceptable Metric Equivalents

in. 1/64 1/16 1/8 850°F NPS 3

mm 0.4 1.5 3 454°C 80

031801

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