Oil & Gas

Pipes, flanges, fittings and gaskets

CRS PLUS sources the piping bill of materials for oil and gas, utility and process projects — seamless and welded line pipe, flanges, butt-weld and forged fittings, gaskets and stud bolts — to API and ASME standards in carbon, low-temperature, stainless and duplex grades, with HDPE, GRP and expansion joints on request. Every item is supplied with its mill test certificate.

Product families

Sourced through the qualified supplier base. Listing does not indicate stock held by CRS PLUS — availability, origin and lead time are confirmed per enquiry, and every quotation states the certification that governs the supply.

Line pipe and seamless pipe

  • API 5L PSL1 and PSL2, grades B to X70, seamless and welded
  • ASTM A106 grade B seamless for high-temperature service
  • ASTM A333 grade 6 for low-temperature service
  • ASTM A312 TP304/316L and A790 duplex stainless
  • Coated pipe: 3LPE, FBE, galvanised

Supplied by NPS and schedule to ASME B36.10 and B36.19, in single or double random lengths.

Flanges

  • ASME B16.5 weld neck, slip-on, blind, socket weld, threaded and lap joint, NPS ½ to 24
  • ASME B16.47 series A and B, NPS 26 to 60
  • Raised face, ring-type joint and flat face
  • ASTM A105, A350 LF2, A182 F304/F316/F51

Class 150 to 2500. Orifice flanges and spectacle blinds on request.

Butt-weld fittings

  • ASME B16.9 elbows 45° and 90° long and short radius, tees, reducers, caps
  • ASTM A234 WPB carbon, WPL6 low-temperature
  • ASTM A403 stainless, A815 duplex
  • Wall thickness matched to pipe schedule

Seamless and welded, in the same grade family as the pipe they join.

Forged fittings and outlets

  • ASME B16.11 socket-weld and threaded elbows, tees, couplings, unions, plugs
  • Class 3000, 6000 and 9000
  • Branch outlets — weldolet, sockolet, threadolet, elbolet
  • ASTM A105, A350 LF2, A182

Small-bore piping and branch connections.

Gaskets and stud bolts

  • Spiral wound gaskets to ASME B16.20, 316/graphite and other fills
  • Ring-type joint gaskets, oval and octagonal
  • Kammprofile, sheet and PTFE gaskets
  • Stud bolts ASTM A193 B7 / B8 / B16 with A194 2H / 8 nuts, plain, galvanised or PTFE-coated

Sized to the flange class and facing.

Non-metallic pipe, supports and expansion

  • HDPE PE100 pipe and fittings to ISO 4427 / EN 12201
  • GRP and GRE pipe to ISO 14692 for water injection and utility service
  • Pipe supports, clamps, shoes and spring hangers
  • Metallic expansion joints and bellows to EJMA

Sourced on request against the project specification.

How piping components are specified

The parameters below define every item on a piping bill of materials. Supplying them, or the line from the project piping class, allows an exact quotation.

How piping components are specified
ParameterWhat it definesCommon values
Size and scheduleOutside diameter and wall thicknessNPS ½ to 60; SCH 10, 40, 80, 160, XXS to ASME B36.10 / B36.19
Material gradeThe steel specificationAPI 5L B, X42–X70; ASTM A106 B, A333 6, A312 TP316L, A790 S31803
PSL levelProduct specification level for API 5LPSL1 general; PSL2 with tighter chemistry, toughness and NDE
Flange class and facingPressure rating and sealing faceClass 150–2500; RF, RTJ, FF
Fitting standardDimensional standardASME B16.9 butt weld; B16.11 forged; B16.5 / B16.47 flanges; B16.20 gaskets
Material groupFlange rating group per ASME B16.5Group 1.1 carbon; 2.1 stainless; 2.8 duplex
CoatingExternal and internal protection3LPE, FBE, hot-dip galvanised, epoxy lined
Service requirementsAdditions for sour, low-temperature or offshore dutyNACE MR0175; Charpy impact at −46 °C; NORSOK M-650 for duplex
Certification levelInspection documentationEN 10204 3.1 standard; 3.2 with third-party witness

API 5L vs ASTM A106 vs ASTM A333 — which pipe grade

The three most common carbon steel pipe specifications on an oil and gas enquiry, and what separates them.

API 5L vs ASTM A106 vs ASTM A333 — which pipe grade
PropertyAPI 5LASTM A106ASTM A333
Intended servicePipeline transportation of oil, gas and waterHigh-temperature process pipingLow-temperature service
GradesA, B, X42 to X70A, B, CGrade 1, 3, 6, 8
ManufactureSeamless or weldedSeamless onlySeamless or welded
Toughness requirementPSL2 requires Charpy testingNot required by defaultCharpy impact at low temperature mandatory
Typical useFlowlines, gathering, transmissionRefinery and plant pipingLNG, refrigeration, cold climates
Dual certificationCommonly dual-certified with A106 BCommonly dual-certified with API 5L BSometimes dual with A106

What the mill test certificate states

No manufacturer-specific figures are published here: CRS PLUS sources from several mills and manufacturers and each issues its own certificate, which governs. These are the parameters and tests reported on a mill test certificate for pipe, flanges and fittings.

What the mill test certificate states
Document or testStandard or method
Chemical compositionHeat analysis and product analysis per the material specification
Tensile propertiesYield, tensile strength and elongation to ASTM A370 / ISO 6892
Charpy impactASTM A370 / ISO 148 at the specified temperature, where required
HardnessASTM E10 / E18; NACE limit where specified
Hydrostatic testAPI 5L / ASTM A530 on pipe
Non-destructive examinationUT or ET on seamless pipe; RT on welded; MT/PT on forgings as specified
Dimensional inspectionOD, wall, ovality, straightness, length to the standard
Heat number and traceabilityStamped or stencilled on each piece and matched to the certificate
Coating inspectionThickness, holiday and adhesion where coated
CertificationEN 10204 3.1; 3.2 with third-party witness on request

Supply terms

Origin
Sourced per enquiry from a qualified supplier base of mills and manufacturers in China, India, Europe and the Gulf. Origin and certifying body are stated on each quotation.
Incoterms
Ex-works and FOB as standard. CIF, CFR and DAP available to GCC, Levant, Red Sea, East and West African destinations.
Documentation
Mill test certificate to EN 10204 3.1 as standard, 3.2 with third-party witness on request; commercial invoice, packing list, bill of lading, certificate of origin.
Inspection
Third-party inspection at source available on request through recognised inspection agencies. Inspection scope agreed on the purchase order.
Lead time
Standard sizes and grades from stock to six weeks. Made-to-order items and large parcels eight to sixteen weeks. Confirmed per quotation.
Enquiry detail
Size, schedule or wall thickness, material grade and standard, quantity or length, end preparation, coating, any NACE or impact-test requirement, and the certification level. A line from the piping class or MTO covers all of this.

Frequently asked questions

What is the difference between seamless and welded pipe?

Seamless pipe is formed from a solid billet without a weld seam and is preferred for high-pressure, high-temperature and sour service. Welded pipe — ERW, HFW, LSAW or SSAW — is formed from plate or strip and welded, and is more economical in larger diameters and thinner walls. API 5L covers both; ASTM A106 is seamless only. The project piping class states which is acceptable.

What does PSL2 mean on API 5L pipe?

API 5L defines two product specification levels. PSL1 is the standard quality level. PSL2 adds mandatory Charpy impact testing, tighter limits on carbon equivalent and chemistry, mandatory non-destructive examination, and traceability requirements. Transmission pipelines, sour service and offshore work are normally specified PSL2.

When is a weld neck flange used rather than a slip-on?

A weld neck flange has a tapered hub butt-welded to the pipe, giving full-strength joint integrity and good fatigue performance; it is specified for high pressure, high temperature, cyclic and hazardous service. A slip-on flange slides over the pipe and is fillet-welded inside and out; it is cheaper and easier to align but rated lower for fatigue and is generally limited to lower-pressure utility service. Most oil and gas piping classes specify weld neck.

What is a spiral wound gasket and how is it specified?

A spiral wound gasket is made of alternating windings of a metal strip and a soft filler, usually 316 stainless steel with flexible graphite or PTFE, with an outer centring ring and often an inner ring. It is specified by flange size and class to ASME B16.20, winding and filler material, and ring materials. It is the standard gasket for raised-face flanges in oil and gas service.

What should be on the mill test certificate?

The heat number, the material specification and grade, chemical analysis, mechanical test results — tensile, yield, elongation, and Charpy impact where required — hardness where specified, the hydrostatic test and any NDE performed, and dimensional confirmation, all signed by the manufacturer’s inspection department. The certificate should be EN 10204 3.1 as a minimum, and 3.2 where the project requires third-party witness.

Can pipe be supplied dual-certified?

Yes. Seamless carbon steel pipe is commonly manufactured to meet both API 5L grade B and ASTM A106 grade B, and stainless pipe to both A312 and A358 or A778. Dual certification is stated on the mill certificate and allows one stock to serve both piping classes. Specify dual certification on the enquiry where the project piping class permits it.

Where is the material sourced from?

CRS PLUS sources pipe, flanges and fittings from its qualified supplier base of API-licensed and ISO-certified mills and forges in China, India, Europe and the Gulf. Origin and the certifying body are stated on each quotation. CRS PLUS does not name manufacturers on this page and holds no distribution or agency agreement with any of them.

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