Gasket_rtj.docx

for moderate pressure piping if one uses spiral wound gaskets with proper bolt stress, is it a less reliable seal against leak compared to RTJ ? Many refinery operating companies use RTJ flange for steam & hydrogen service above 600 psig & hydrocarbon above class 600 & for all other services class 900 and higher. But, the concern is that RTJ is expensive, when done in field and requires flexibility in connecting piping for gasket installation & removal.

A RF flange lets you pull the valve or flange away from the other face easily and quickly, and the size of the standard gasket lets you hold the gasket in place with the lower (loosened) bolts across the bottom of the flange as the gasket slips back in place from above. So the gasket isn't too likely to get misaligned and block flow or leak.