ASME Compliance Checklist for Pipe Fab Bids: Never Miss a Spec Requirement Again

Every experienced estimator has the same story: a bid that looked airtight went out, came back from the customer with a clarification list, and buried in that list was a spec callout nobody addressed. Suddenly you're either eating scope, renegotiating, or quietly losing the job to a shop that read the spec more carefully.

This is a bookmarkable checklist for the four codes that show up in almost every industrial pipe fab bid we see. Use it as a final pre-ship review. Print it, pin it, whatever.

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ASME B31.3 — Process Piping

The code you're bidding against 80% of the time. Anywhere hydrocarbons, chemicals, or high- pressure process fluids are moving, B31.3 is in play.

Your bid must address:

• [ ] Material specifications. Every line item traced to an approved B31.3 Table A-1 material, with mill test report (MTR) requirements explicitly called out.
• [ ] Fluid service category. Normal, Category D, Category M, Severe Cyclic, or High Pressure. This drives inspection and NDE requirements downstream.
• [ ] NDE scope and coverage. Radiographic (RT), ultrasonic (UT), magnetic particle (MT), liquid penetrant (PT), or visual (VT). With percentage coverage. "Per code" is not a scope.
• [ ] PWHT. When required (based on material, thickness, P-number), with procedure reference.
• [ ] Hydrostatic or pneumatic test. Pressure, duration, media, pass criteria.
• [ ] WPS and PQR documentation. Confirmation your welding procedures are qualified to cover the scope.
• [ ] Inspector qualifications. Who's stamping, under what authority.

Common gap: RT coverage percentage not called out. Customer assumed 20%, you priced 5%, change order ensues.

ASME Section IX — Welding and Brazing Qualifications

The code that backs up your WPS/PQR claims. You don't price against it directly, but every bid under B31.3, B31.1, or Section VIII implicitly requires Section IX compliance.

Your bid must address:

• [ ] WPS coverage. Procedures qualified for every material spec, thickness range, position, and process (SMAW, GTAW, GMAW, SAW, FCAW) in the scope.
• [ ] Welder performance qualifications. Roster of qualified welders on file, current within the last six months.
• [ ] Filler metal and base metal combinations. F-numbers, A-numbers, P-numbers match the scope materials.
• [ ] Procedure re-qualification trigger awareness. If scope requires a material or process outside your current library, bid should note qualification lead time.

Common gap: scope includes a material you haven't qualified for, nobody notices until week two of fabrication, and the schedule slips.

API 570 — Piping Inspection Code

If the scope is repair, retrofit, or inspection of in-service piping, API 570 is in play. This is especially common for refinery turnaround work.

Your bid must address:

• [ ] Authorized Inspector (AI) coverage. You have one on staff or you subcontract — stated explicitly.
• [ ] Inspection intervals and scope. CMLs, TMLs, thickness surveys, visual inspections per the owner's program.
• [ ] Repair vs. replacement methodology. Hot tap, weld repair, in-kind replacement, with applicable API 570 section references.
• [ ] Data management and reporting. How inspection data is captured, documented, and delivered to the owner.

Common gap: bid treats API 570 as an afterthought, customer flags it as a non-responsive bid.

NACE MR0175 / ISO 15156 — Sour Service

Required for any piping handling H₂S-containing fluids above certain partial pressures. Very common in O&G upstream and midstream work.

Your bid must address:

• [ ] Materials selection. Every component verified against MR0175 acceptable materials lists for the service environment.
• [ ] Hardness limits. Maximum hardness (typically 22 HRC for carbon and low-alloy steels) after welding and PWHT.
• [ ] PWHT requirements. Often mandatory even where B31.3 alone wouldn't require it.
• [ ] Documentation. Certification that materials, welding, and NDE all meet MR0175 criteria, with traceability.

Common gap: MR0175 mentioned in customer spec, nothing in your bid addresses hardness limits, and now you're in the weeds on material cert review during clarifications.

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Download the printable version

How to use this checklist

Print it. Tape it next to every estimator's desk. Before any bid ships:

1. Circle the codes that are active on this bid (customer spec will tell you).
2. Walk each checkbox. If the bid language doesn't explicitly address it, the bid isn't done.
3. Red-line the draft, add what's missing, send.

This takes 15 minutes per bid and catches the gaps that cost you jobs.

Or: let BidAnvil run the checklist automatically

Every bid BidAnvil generates runs this exact checklist against the draft. Every code flagged in the customer's spec gets cross-checked against every checkbox above. Gaps are surfaced to the estimator before the bid ships — not after the customer's clarification list lands in your inbox.

You don't need our tool to use the checklist. But if you're running more than five bids a month against varying codes, running it by hand on every one is the kind of task that AI does better than humans do. Humans forget. AI doesn't.

See what the numbers look like for your shop →

Or if you want to talk through how this integrates with your existing QA process, book a 15-minute call.

Further reading: the complete pipe fab bid template covers every section a bid needs, not just the compliance parts.