As per Clause UNF-95 of ASME Section VIII, Div. 1, there is a mandatory requirement of PTC for all the category A and B joints of titanium and zirconium welds.

A production test plate of same specification, grade and thickness shall be made of sufficient size to provide one face bend and one root bend or two side bends dependent upon the plate thickness.

Here, thickness of the plate is essential variable. for each plate thickness, each PTC is required.

Also, type of welding process i.e. manual or Automatic shall also be covered by each PTC.

Reference: ASME BPVC Section VIII, Div. 1.

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