PWHT requirement

By jon20013 (*****)

Date 01-21-2006 10:55

D1.1 does not require PWHT but instead provides guidance for the engineer to decide whether or not it should be done. Typically in these cases such requirement is provided in contract documents or specifications.

By fakhmed Date 01-21-2006 11:34

Thanks for your prompt and precious reply,

It is not specified in the contract to perform or not a PWHT for shuch type of welds. However, as manufacturer we are responsible for its performance.

Can you advice on which bases can I decide of the applicability of the PWHT for our case?

By jon20013 (*****)

Date 01-21-2006 14:57

There is guidance within D1.1 that can be clearer than my guidance as I am now writing from my home computer (no access to D1.1), however factors such as material type (carbon content, etc.,), thickness and loading will all come into play. If any doubt, definately read the D1.1 guidance and, as a minumum, make sure you follow any preheat requirements.

By fakhmed Date 01-23-2006 07:05

Thank you again.

Preheat was adequately performed as per the requirements of D1.1.

Would you please inform me which guidance specified in D1.1 shall I follow to make decision?

Paragraph 3.14 specifies some conditions to not perform PWHT, but don't clarify when the PWHT shall be performed; only if specified in the contract. But suppose that the client has't any competency to decide if PWHT shall be performed or not. We, as manufacturer, shall not ignore such condition which may be vital for the weld performance.

What is your opinion

By jon20013 (*****)

Date 01-23-2006 13:06

I am now reading from the 2004 Edition of D1.1 and if you refer to paragraphs 5.8.2 and 5.8.2 and also in the Commentary; C5.8 you should find the guidance you need to make your decision.

As for the client not knowing certain aspects of a given project, this is fairly common in my experience.

Welding is a science unto itself and often the client employs Mechanical Engineers or Civil Engineers or even Chemical Engineers to design their plants, facilities, structures and while these Engineers may be very well versed in their particular discipline and maybe have a decent knowledge of welding matters, it is seldom their field of special knowledge.

Good luck!