Cast Steel Gate Valve Welding Inspection

Cast Steel Gate Valve Welding inspection is generally divided into two parts:

1. Document review

WPS, PQR, and welder qualification WPQ are required.

Whether the WPS provided covers the important variables such as parent material, welding material, welding method, groove form, thickness, preheating, and post-weld heat treatment required by the order.

According to ASME Volume IX and NB/T47014, the WPS evaluated has corresponding important variable regulations. If the important variables change, they must be re-evaluated.

2. On-site welding inspection

VT (visual inspection) is usually used to check whether there are obvious welding defects, such as cracks, undercuts, weld nodules, poor forming, burn-through, spatter, etc.

For sealing surface cladding, PT is usually used to check whether there are cracks, and the hardness of the sealing surface needs to be tested;

Check the inlay welding of the valve seat and the valve body. Basically, as long as the appearance is flat, there is no undercut, misalignment, and weld nodules, it is fine.

Check the structural welds such as extension pipes, when the order requires, RT or UT is required to check the internal quality.