About this Abstract |
| Meeting |
2026 AWS Professional Program
|
| Symposium
|
2026 AWS Professional Program
|
| Presentation Title |
Sense and Nonsense - PWHT for Repair of Surfacing Welds for H2S Service |
| Author(s) |
Richard L. Holdren, David Hebble |
| On-Site Speaker (Planned) |
Richard L. Holdren |
| Abstract Scope |
Qualification of welding procedures for corrosion-resisting overlays (CROs) and buildups on components subject to survival in hydrogen sulfide (H2S) environments requires testing in accordance with ASME, API, and NACE standards. In addition to the standard testing specified in ASME Section IX, these procedures must also satisfy the performance requirements found in various API standards as well as the corrosion-resistance requirements of NACE.
This testing program requires that a given weld test coupon be subjected to two PWHT holding times. The shorter time is the minimum holding time for the original production weld. The longer PWHT time then provides verification that the base and filler metals will withstand multiple PWHT required for each repair/rebuild of these components. That way, the life of the component can be extended by the replacement or repair of the degraded surface. The current requirements state that the minimum PWHT time must be applied for each repair/rebuild cycle.
Research has revealed that the current requirements may be excessive, and that shorter PWHT times can accomplish the same result without the risk of degrading the base and filler metals being used. This paper will describe recommendations for dramatically reducing the PWHT times to both reduce cost and, more importantly, reduce the potential for material degradation due to excessive exposure to PWHT temperatures. The presentation will also discuss how PWHT can be eliminated completely. |
| Proceedings Inclusion? |
Undecided |