Technical resources for better gasket selection

Use a spiral wound gasket for standard ASME B16.20 flanges where bolt load is predictable and the joint is not frequently opened - it is the most cost-effective sealing element for most refinery and chemical duty. Choose a kammprofile gasket when bolt load is limited, flange surfaces are worn or slightly out of parallel, the joint is thermally cycled, or you need a lower seating stress with a tighter leak rate. Kammprofile also handles repeated assembly better because the solid metal core does not lose recovery the way a wound element can.

RTJ gaskets are specified for ring joint flanges to API 6A and ASME B16.5 in high-pressure service, typically Class 900 and above, and for wellhead, pipeline, and high-temperature hydrocarbon duty. The seal is created by controlled plastic deformation of a solid metal ring into the flange groove, so it tolerates far higher pressures than a wound gasket. The trade-off is that the flange must be an RTJ groove design and the ring hardness must be softer than the flange to avoid damaging the groove.

Virgin PTFE is normally limited to about 200 degrees C continuous service, and creep becomes the governing failure mode well before the chemical limit is reached. Expanded PTFE handles roughly the same temperature but resists cold flow far better under sustained bolt load. Above 200 degrees C, move to flexible graphite for reducing and neutral media, or to a metallic or kammprofile construction with a graphite facing for high-temperature duty.

Pressure and temperature ratings are not independent. A gasket rated for Class 1500 at ambient may be limited to a much lower pressure at elevated temperature, because both the flange rating and the gasket material derate with heat. Always check the flange pressure-temperature rating table for the material group first, then confirm the gasket construction and filler are suitable at the resulting design point, and finally confirm available bolt load is sufficient to reach the seating stress the gasket needs.

Send the flange standard and size, pressure class, design and operating temperature, process medium and concentration, whether the joint is thermally cycled, and any applicable client or plant specification. If you have a drawing or a failed sample, that is even better. With those details our application engineers can confirm the construction, metal grade, filler, and standard, and quote against your actual service conditions rather than a generic catalogue part.

Yes. We manufacture to drawing and to sample, including non-standard outside and inside diameters, legacy flange sizes, and vessel and heat-exchanger geometries that no longer match a current standard. Provide the measured dimensions or the original drawing and we will confirm the construction and tolerances before manufacture.