Q. Explain about Hardness testing?

When indicated on equipment or vessel data sheets, hardness testing shall be performed as follows:

a) Perform hardness tests at or near the centre of the weld or surface to be tested on the side exposed to the process environment. Prepare the surface in accordance with ASTM E-10. Use a Telebrineller portable tester to measure hardness.

One hardness test for each 3.05 m (10 ft) or fraction thereof, for each longitudinal seam of each course. One hardness test for each 3.05 m (10 ft) or fraction thereof, for each vessel circumferential seam. One hardness test for each nozzle to shell weld.

One test on each surface cut with oxy-fuel or Arc-Air which is left unwelded on the finished part. One test on each area where a temporaryweld was made and removed.