Gasket Compression Stops Application and Design
Gaskets may incorporate a compression stop to limit the applied compression and ensure damage will not occur due to excessive load. Gasket compression stops will also prevent excessive bowing of the cover flange due to excessive force applied by the fasteners.
Compression stops are typically molded or installed into the the gasket material, and are normally a rigid material which is compatible (galvanic corrosion) with the materials used within the target assembly. Compression stops are often manufactured from standard gauge sheet, or cut to desired thickness from rod or tube stock.
Normally gasket compression stops are cut to a known length / thickness less than the thickness of the gasket material which the stop is installed. A good practice for compression stop spacing is a minimum distance from the edge of the fastener hole to the edge of the compression stop material to equal not less than the gasket material thickness - see Figure A below.