Post-Weld Heat Treatment (PWHT) Record

An ASME-aligned record sheet capturing all data a Code inspector needs to accept a PWHT cycle — temperature parameters, TC layout, cycle data, acceptance vs Code requirement, and sign-off.

Post-Weld Heat Treatment (PWHT) is required by ASME Section VIII Division 1 (UCS-56), ASME B31.3 (Table 331.1.3), and many customer specifications when material P-Number, thickness, or service condition demands stress-relief or hydrogen out-gassing. The PWHT record proves to an Authorized Inspector or TPI that the cycle met both the WPS and the Code.

Use this template at the start of every PWHT cycle. Capture process parameters before heating, log the cycle data points during the run, and complete the acceptance and attachments sections before submitting to QC. The TC layout and attachments table are designed to match what an Authorized Inspector reviews during dossier handover.

Atlantis NDT delivers customized PWHT records integrated with chart-recorder data exports, automatic Code compliance checking, and digital signatures via our reporting platform.

Auto-import chart-recorder data, run Code-compliance checks, and sign digitally.

What this page covers

  • Overview
  • Sections Included
  • Related Free Templates
  • Need digital PWHT records?

Key points covered

  • Heat-treatment identification — record number, project, component / weld ID, WPS / PQR reference
  • Process parameters — soak temperature + tolerance, hold time, heating / cooling rate, loading temperature, soak band width
  • Thermocouple layout — 10 TC positions, attachment method (capacitor discharge / strap), channels
  • Cycle data — temperature at cold start, end of heat ramp, soak start / mid / end, end of cool ramp, below 600 deg F
  • Acceptance check vs code — soak temperature, hold time, rates, max differential, chart continuity
  • Attachments checklist — chart trace, calibration certificates, TC layout sketch, WPS / PQR, MTR
  • Sign-off — PWHT operator, NDT Level II/III witness, QC inspector, Client / TPI

Related: Atlantis NDT ERP · Digital Twin platform · NDT inspection software · NDT reporting software · ASNT Level III consulting · NDT training. Book a free consultation.

The PWHT record as code evidence

Post-weld heat treatment is invisible in the finished weld, which is exactly why its record carries so much weight: the chart is the only proof the metallurgical condition the design assumed actually exists. The record must tie together the procedure's required cycle (heating rate, soak temperature and time, cooling rate — each with code tolerances), the thermocouple placements against the requirement, the calibrated recorder identity, and the actual chart with excursions explained. An unexplained dip during soak is not a formality — it is a question about whether the joint met code, and the answer must be on file before the hydrotest, not reconstructed after.

Cross-reference the PWHT record to the welds it covers by joint number; a chart that cannot be tied to specific joints proves nothing about any of them.

Where this document sits in the wider system

Templates fail as loose files and work as parts of a system: this document should cross-reference the records that feed it and the decisions it feeds, carry a revision history like any controlled document, and live where the whole team retrieves the CURRENT version — not the copy someone improved privately last year. Companies running their inspection operations on a single system of record generate most of these documents from live data rather than filling them by hand; that is the practical difference between managed records and managed paperwork. Browse all templates and resources, or ask how the generated version works.