Spiral Wound gaskets utilizes an external ring where the ID is grooved to insert a sealing element. The external ring or centering ring is designed to properly guide the gasket on a bolted flange accurately centering gasket. The Centering also provides additional radial strength to prevent gasket blowout and acts as a compression limiter.
300# Spiral Wound Gaskets – ASME B16.20
$1.82 – $101.30
