Tensile test - gauge length

[jason12122]

I have a requirement to measure the % elongation of tensile tests when testing a PQR to ASME IX.

However the parralel length shown in the dimensions to ASME IX is weld width plus 1/2" (13mm). This is not long enough for the clip gauge.

The gauge length / parallel length of the specimen makes no difference to the outcome of the UTS, therefore i see no reason to duplcate tests.

However-

Q) If i increase the parallel length, does this invalidate the test to ASME IX.

Q) I am i required to test two more samples with the correct gauge length to ASME IX? (this will entail welding more coupons, arranging third part and client witnesses to re-visit)

Q) How do i go about getting clarification from the comittee, as to whethter or not the size stated is specified or a minimum size (Thus allowing elongation measurement), as it bears no relation to the outcome of the test (to measure the UTS.)

Any help would be appreciated.

I work in a materials test laboratory, and as such i have to meet the specification, regardless of how silly the requirement may be.

 

[metengr]

Weld procedure qualification in accordance with ASME Section IX does not require percent elongation in a tensile test. This is why bend tests are performed to assure minimum ductility of the weld deposit and base metals in the weld region.

Also, increasing parallel width does not invalidate measuring percent elongation because the requirement you stated below;

However the parallel length shown in the dimensions to ASME IX is weld width plus 1/2" (13mm). This is not long enough for the clip gauge.

is a minimum requirement, not a maximum value. So, yes, you can increase the size of the specimen to test for percent elongation, if that is what you need. Please re-review ASME Section IX, Welding Data, QW-462.