Flange Rubber Gaskets

Flange rubber gaskets seal between two flat pipe or equipment flanges by converting bolt preload into uniform compression across the gasket face. They are the practical alternative to O-ring grooves when the joint is large, the flange is already machined flat, or the equipment must be opened regularly for cleaning and inspection. Two geometries dominate pipe flange service. Full-face gaskets extend to the outer edge of the flange and cover the bolt holes, protecting the entire mating surface and resisting flange distortion. Inner-bolt-circle (IBC) ring gaskets sit inside the bolt circle, leaving bolt holes clear; they use less material and are easier to align on large flanges. Both types are used on ASME Class 125/150 flat-face flanges and comparable DIN/EN flanges. Material selection follows the media: EPDM for water and steam, NBR for oil and fuel, FKM for chemicals and high temperature, and PTFE for aggressive media. Typical thicknesses are 1/16 in and 1/8 in. The gasket must be compressed 15–30% of its thickness to seal, which means bolt torque and flange stiffness are as important as gasket material. We cut flange rubber gaskets from drawing, from ASME B16.21 templates, or to your bolt-circle and ID/OD dimensions. Send the flange size, pressure class, material, thickness and quantity for a quote.