We had carried out PQ for rail welding in 1993.
The size of PQ is "JIS 37KG/M" and the process was "SMAW".
at that time, kind of test are U.T, Tension test, Hardeness test.
Result of all tests were good.

But now,
We will be welding the rail of "JIS 73kg/m".
"JIS 73kg/m" was equal to "JIS 37KG/M, Mechanical and Chemical properties except dimensions.
is it need of NEW PQ or not?

Please give advise.
Thank you