AWS D1.1 Preheat

[bulldog2002]

Can a PQR that has been qualified but was not done with pre-heat be used (exact same plate material, joint, welding process, etc...) when customer documents require pre heat on production product. In other words: can a PQR that didn't have preheat be used for production when pre-heat is required?

 

[bulldog2002]

This is for CVN test requirements.

 

[Duwe6]

". . . can a PQR that didn't have preheat be used for production when pre-heat is required?" Absolutly, but it does not qualify for a Charpy Notch Toughness requirement.

"This is for CVN test requirements." If the customer is willing to just have you use a specified minimum preheat & interpass temperature, you are OK.

If the customer wants to see a qualified WPS with tested minimum CVN values, you need to qualify a WPS.

I'll bet that your Salesman/Estimator missed a CVN requirement, right?

 

[bulldog2002]

Duwe6,
Thank you for the response. Our customer does specify a very exact preheat, I think at this point it is best to ask our customer if they would accept out PQR and add preheat.

 

[Mr168]

Was the PQR tested with impacts?

What code year are you working to? There are limitations in the D1.1 essential variables, but arguably, you could increase the production preheat using the non-preheated PQR if you do not increase your maximum interpass temperature >100°F.

 

[bulldog2002]

Mr168,

This PQR is for a CVN impact required test. I am working to AWS D1.1, 2010 edition.

 

[weldtek]

Have you reviewed Table 4.6? Preheat greater than 100 F over that qualified is a supplementary essential variable.

 

[Mr168]

Be careful with table 4.6. It indicates that an increase of 100F over that qualified applies to MAXIMUM preheat or interpass. In AWS space, maximum preheat has the same meaning as maximum interpass.

e.g.

If I have a PQR with 50F min preheat and a max interpass of 500F, I can write a WPS for 200F minimum preheat and keep my max interpass the same, and still meet CVN supplementary essentials.