Non-Conforming PreHeat - ASME B31.3

[JLBREAU]

ASME SA335 F11 (P4) material was welded using 150'F Preheat as per their WPS. However, Code of Construction being ASME B31.3 states a minimum preheat temperature of 250'F shall be applied. There are 700 socket welds completed like this.
I recommended Heat Treatment for the welds and Hardness testing to prove the material won't be brittle, but Client isn't buying it.

What other options can be done in regards to testing to ensure the integrity of these welds? They are 1-1/4" STD SA335 pipe into Couplings.

Are there any exemptions from these minimum preheat temperatures in ASME B31.3?

The WPS states a minimum preheat of 150'F Note (6), Note 6 says: "The 150'F minimum specified preheat is the lowest temperature at which this WPS can be used to perform welding. The minimum specified temperature does not imply that the use of minimum permissible preheat is acceptable for all welds on all base material thickness. This WPS is to be used in conjunction with governing codes."

ASME B31.3 Para 330.1.1 states "Unless specified otherwise in the engineering design, the minimum preheat temperatures for materials of various P-numbers are given in table 330.1.1"

Could we not perform the PQR for how it was welded with the 150'F, and prove integrity? Make THIS the engineered design as per para 330.1.1, if it passes?

I am actually a third party trying to help a situation.

 

[metengr]

Since this is a nonconformance, the disposition can be done several ways. I think your approach of simulating the work done in production by using the actual preheat and qualifying the technique would be the best approach, and defendable. Surface NDT, like Liquid PT or wet MT of the completed welds is another approach to check for delayed cracks (from lack of preheat).

Hardness testing can be tricky and provide results that may not be defendable because of possible technique and finger pointing.

 

[jweld97]

ASME B31.3 Para 330.1.1 states "Unless specified otherwise in the engineering design, the minimum preheat temperatures for materials of various P-numbers are given in table 330.1.1"

Would the WPS noted in your question not be an inherent part of the engineering design? Do the design and/or construction drawings detail the WPS to be used? Would that not satisfy the above comment from ASME B31.3? I also agree with metengr's statements for NDE to be performed to defend the construction practice and WPS requirements.

 

[DekDee]

Guys,
I posted this response in the AWS section.

JLB,
That clause "engineering design" relates to requirements over and above the code requirements.
The project specifications and/or engineering design can be as stringent as they want but cannot be less than code requirements.
Bottom line is 250F minimum preheat - anything less and the welds do not comply with the code,

Is there any evidence of what the "actual" preheat was ?
Cheers,
DD

This is an excerpt from B31.3

engineering design: the detailed design governing a piping
system, developed from process and mechanical
requirements, conforming to Code requirements, and
including all necessary specifications, drawings, and
supporting documents.
(2) Designer. The designer is responsible to the
owner for assurance that the engineering design of piping
complies with the requirements of this Code and
with any additional requirements established by the
owner.
(3) Manufacturer, Fabricator, and Erector. The manufacturer,
fabricator, and erector of piping are responsible
for providing materials, components, and workmanship
in compliance with the requirements of this Code and
of the engineering design.

 

[SectionIX]

JLBREAU,

The owner company should have their Regulatory and Legal departments examine this non-compliance as they will need to accept the risk of placing into service welds that may be structurally sound but do not meet ASME B31.3 preheat requirements.

Other options could include:

1. Finding a relevant ASME Code Interpretation that clearly resolves this issue in your favor.

2. Confirm that these welds fall under ASME B31.3 jurisdiction...which appears to be the case. If not, problem solved.

These could be the best fillet welds ever made, but if one fails, the Regulator will undoubtedly focus in on preheat as a contributing factor. A routine inspection by a savvy auditor might also bring this issue to light.

It’s never a problem until it becomes a problem.

 

[StoneCold]

It might be of interest to you to run welding specimen test at 50F, 100F, 150F, 200F, 250F, 300F to get an idea of what impact, if any low preheat has on the welded joints.
Do a bend test, tensile test and hardness test on all of them. If you can see a trend in the data it might give you more confidence in whatever decision you decide to make.

Regards
StoneCold

 

[weldstan]

The Owner has the right to make you cutout all the welds. It is also understood that socket welds involve relatively thin walls and small diameters resulting in slow cooling. Multi-pass welds where the interpass temperature is expected to be > 450 F will alleviate hydrogen assisted cracking concerns. It is also assumed that low hydrogen processes will be used. Your best bet to convince the owner to accept the welds is to simulate the welding and perform some hardness tests on the weld and HAZ. Magnetic particle testing of all the completed welds is recommended.