Heat Input

[GemmellG]

Trying to understand the difference in heat input recorded in WPS & PQR I am reviewing some welding procedures for an upcoming project. The WPS Heat input is higher than the PQR. My take on this is the heat input calculated during the welding of the test coupon & recorded on the PQR. There is a percentage add to the actual heat input & recorded in the WPS. I have reviewed ASME Sec IX QW-409 & can’t find any information regarding this.

 

[metengr]

Look at QW-409.1 below;

QW-409.1 An increase in heat input, or an increase in
volume of weld metal deposited per unit length of weld,
over that qualified.

Seems straight forward, if the WPS heat input is higher than that qualified on the PQR, you need to re-qualify the WPS. Look carefully at how the heat input was determined for both.

By the way, the above excerpt is from the 2010a Edition of Section IX.

 

[wegm]

You could have a look at this link:

http://www.weldinguide.com/gdanastasiadis/viewtopic.php?f=5&t=391

 

[stanweld]

Is the production part subject to heat input control; i.e., impact testing required, corrosion resistant ovelay? If not heat input is not an essential variable. If so, as per metengr, requalify the procedure or revise the WPS to define the heat input recorded on the PQR.