Chemical analysis location and coupon for Overlay Pipe As Per ASME Sec IX

[Ishack]

Dear Experts,

A CRO (Corrosion resistant weld overlay) PQR is done on pipe in 5G position. Chemical analysis is to be done as part of the PQR and as per ASME Sec IX Figure QW-462.5(b), for 5G and 6G position the locations are mentioned for chemical analysis. However there is a note states "specimen required for a minimum of three locations".

kindly advise what does it mean. do we need to extract the chemical analysis specimen at least three location (three specimens) or a single specimen at uphill position is sufficient as mentioned in QW 405.4

 

[Dhurjati Sen]

Otherwise the note would not have been there.

DHURJATI SEN
Kolkata, India

 

[Ishack]

But it is contradictory to the statement mentioned in QW-405.4
if it is really required to have three samples minimum at different locations of QW 462.5(b), then it is better to perform PQR on a plate of similar P number utilizing uphill position of 3G which will qualify all position and dia is not an essential variable.