Transfering of PQR weldpass average or single values to WPS 2

[kjell123898]

We have performed a PQR of a 45mm plate in S355 material and weld position 3G. Welding method is FCAW. The number of single welding layer is 50 pcs achieved during the PQR welding.
Please may someone state which of the calculation methods are most appropriate when observed heat input values to be transferred to the applicable WPS.
Question: Shall we use an average heat input value based on all 50 passes (+/- 10% min/max range)? or shall be rather use the minimum and maximum heat input value from the single pass to determine the heat input range in the WPS?
This matter is the subject of extensive discussions and I feel it will be like that one strives for a wps with greater validity than technical advisable....

Kjell Gr°nvold

 

[DekDee]

sjones,
You may well be correct but the only mention I can find of doing 2 x test plates ( 1 x low heat input and 1 x high heat input) is Section 8.4.2 Welding Positions.
If you require all positional welding ( and impact / hardness tests are required) then 1 x plate in PF and 1 x plate in PC positions are required.
How this relates to kjells PQR/WPS which has all positions noted as qualified on the WPS but only 1 x plate (PF) actually qualified via PQR I am unsure.
As I said previously - I do everything I can to avoid ISO/ BS /EN codes / standards,
Regards,
DD

 

[SJones]

DD - see 8.4.8



Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

 

[Ishack]

I would like to address it based on either ASME Sec IX or AWS D1.1 as I am not familiar with ISO codes.

There is no specific instruction given in the above codes that, how it shall be recorded. However as a standard practice, the heat input for all the passes in each layer (start from root pass to final cap) will be calculated and recorded in the PQR.
The heat input recorded for each layer (maximum value of heat input shall be taken in case of multi passes in a single layer) will be considered as the maximum heat input that can be allowed for production job especially where impact / CVN requirement is applicable in fact the maximum value of heat input only becomes an essential variable when impact/CVN test is applicable, otherwise code doesn't restrict it. This value will be transferred to WPS as a maximum value of Heat input for each layer. The minimum value of heat input is not considered as an essential / supplementary essential variable by both codes (ASME or AWS) and hence not required to be transferred into WPS unless the specification / construction code demanded to mention it.

As per my previous experience, Most of the specifications are directly specifying the required minimum heat input value, hence it can be mentioned in the WPS directly irrespective of the values recorded during the procedure qualification (be ensured that the minimum value obtained in the PQR is not less than the required minimum value as per specification).

Correct me if I am wrong.

Regards,

ISHACK M