
ASME B31.3 Pressure Testing Painted Welds
ASME B31.3 paragraph 345.3.1(d) states: All joints may be primed and painted prior to leak testing unless a sensitive leak test is required.
The code therefore allows for joints to be primed and or painted for pressure testing, but the owner’s specifications or site practices may prohibit it. It is important to know what requirements may supersede what the code allows before implementing this practice.
Even with the allowance for primer or paint, insulation is treated differently.

ASME SA-370 Testing of Steel Products
ASME SA-370 is a standard specification that outlines test methods and definitions for the mechanical testing of steel products, including steels, stainless steels, and related alloys. It ensures consistent evaluation of material properties like strength, ductility, and toughness.