Your construction code for pressure safety Valve is API Standard 526 and covers the minimum requirements for design, materials, fabrication, inspection, testing, and commissioning.

If you need directly go to detail of the inspection process review Inspection and Test Plan for Pressure Safety Valve draft sheet.

You need to use the other API Recommendation practices in conjunction of API STD 526 for design and construction purpose.

These are:

    API Recommended Practice 520 for Sizing and Selection

    API Recommended practice 521 Guideline for Pressure Relieving and Depressing Systems

    API Recommended Practice 527 Seat Tightness of Pressure Relief Valves

Between above supporting recommend practices only API RP 527 specifically refers to the inspection and test for pressure safety valve construction.

Pressure safety valve manufacture certification sometimes is mandatory by regulation of local authority.

For example in the state of Minnesota the ASME Code application and stamping for pressure vessel and boiler is mandatory which