/ FAQ
Fasteners & gaskets — common questions
What are ASTM A193 B7 stud bolts?
A193 Gr B7 is a chromium-molybdenum alloy steel stud bolt for high-temperature/high-pressure flange joints, normally paired with A194 Gr 2H heavy hex nuts — the standard bolting for most process piping flanges.
What is a spiral-wound gasket?
A metal winding strip (usually 316L) alternated with a soft filler (graphite or PTFE), often with inner and outer guide rings — a resilient, high-integrity gasket for flanged joints under pressure and thermal cycling, to ASME B16.20.
What gasket types do you supply?
Spiral-wound (B16.20) with inner/outer rings, ring-type-joint (RTJ) in R, RX and BX styles, and non-metallic gaskets (CAF/CNAF, graphite, PTFE, rubber) to ASME B16.21, plus insulating gasket kits for cathodic isolation.
Do you supply coated bolts for offshore / sour service?
Yes — stud bolts & nuts with PTFE (Xylan), HDG or zinc coating, in B7M/2HM controlled-hardness for NACE sour service, with EN 10204 3.1 certification.
