dear all,

i have to execute wpqt soon.
we use material 16mo3 thk10mm for test piece.
refer to the asme ix the min size 150mm length and width 150mm min.
the welding position 3g and plan with backing plate.
rt for ndt method test.

could we attach backing plate at the test pieces same as aws d1.1 clause 4?

kindly please advise.