Guides / Sourcing

What NORSOK and API Actually Qualify for PEEK Parts

September 26, 2026

Sources: manufacturer datasheets and published standards. See editorial standards.

Standards get invoked in oilfield sourcing more often than they get read. A buyer hears “NORSOK qualified” or “API rated” on a PEEK part and reasonably assumes that settles the material question. It usually does not, because these standards qualify a testing process against defined conditions, not a blanket approval that travels automatically with every part made from a similar looking material.

What these bodies actually cover

NORSOK is a set of standards developed for the Norwegian oil and gas industry, aimed at safety, quality and cost efficiency across equipment used offshore. NORSOK M-710, the one most often cited around plastics and elastomers, sets qualification and testing requirements, historically written with elastomeric sealing materials as the primary target, including rapid gas decompression testing.

API, the American Petroleum Institute, publishes standards covering equipment design, materials and testing across the oil and gas industry. API Spec 6A covers wellhead and christmas tree equipment broadly, including material requirements for the metal and non-metal components used in it. ANSI/API 6A718 addresses qualification of non-metallic sealing materials specifically, drawing heavily on the same testing philosophy as NORSOK M-710.

ISO 23936-1 sits alongside both and is the standard written specifically for non-metallic materials, thermoplastics included, in oil and gas production. This is the reference that most directly addresses a machined PEEK part rather than an elastomeric seal, covering how materials like PEEK are assessed for stability in simulated production media. The 2022 edition states that blistering by rapid gas decompression is outside its scope, so decompression resistance needs a separate test basis, such as the method an operator or the equipment maker names.

The overlap between these matters more than any one of them in isolation. A qualification report can reference NORSOK methodology, sit under an API spec’s broader equipment requirements and use ISO 23936-1’s material assessment approach, all for the same part. None of them substitutes for the others.

What a standard qualifies, and what it does not

A standard qualifies a specific material, at a specific grade and often a specific supplier’s resin, tested under specific conditions, against a defined test method. It does not automatically extend to a different grade from the same family, a different resin producer’s version of “the same” material, or the same grade used outside the conditions it was tested at.

This is the gap that causes real problems. A PEEK grade qualified to ISO 23936-1 for one temperature, pressure and media combination is not automatically qualified for a hotter, higher pressure or more aggressive service just because the material family is the same. The qualification travels with the tested conditions, not with the word “PEEK” on a datasheet.

It also does not certify an individual part, only the material and process it was made from. A machined ring can be made correctly from properly qualified stock and still fail if the machining introduced residual stress or a dimensional error the qualification never tested for. The standard and the part quality are two separate questions, and a buyer needs evidence for both.

What documentation actually proves a standard was followed

Four things separate a real qualification claim from a marketing line:

• The qualification test report itself, not a summary sentence, showing the test method, the standard it followed and the pass criteria used.
• The exact material grade and resin producer’s name the report covers, since a qualification for one supplier’s PEEK grade does not transfer to another supplier’s equivalent without its own testing.
• The test conditions, temperature, pressure, media and, where relevant, decompression rate, compared honestly against your actual service conditions rather than assumed to be close enough.
• Traceability from the qualified material to the lot in your parts, which is the same traceability chain covered in verifying PEEK material and is what turns a qualification claim into something you can actually rely on for a specific order.

Background on the service conditions that typically drive these questions in the first place, temperature, pressure, media and decompression rate, is covered in PEEK parts for oil and gas.

Putting it on the RFQ

State the specific standard you need referenced, not just “oilfield rated” or “API compliant.” Ask for the qualification report and the resin producer’s name up front, before quoting, so a mismatch surfaces before the part is cut rather than during an audit. If your service conditions differ meaningfully from a standard qualification’s test conditions, say so and ask whether additional testing is warranted rather than assuming the existing report covers you.

Send the drawing with the standard you need to meet and the actual service conditions, and we match you with shops that can produce the documentation to back it up, not just the part.

Material or stock distributor who already tests and documents to NORSOK, API or ISO 23936-1 as standard practice? Send your vendor profile. Traceable qualification paperwork is exactly the kind of detail we name a vendor for.

See also: ISO 23936-1 for thermoplastics in oil and gas, and how it differs from NORSOK M-710.

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