... rate, save energy.** Stainless steel seat** Unique sealing ring, with saw-tooth sides, embedded directly into disc, bolt-free ... replacement, uniform & tight sealing effect, aspiratory rubber sealing ring, prolonged service life.** Unique taper pin, US patent ... tight for long serviceGood exchangeability** Excellent sealing effect** complies with BS 6755, part1, 1986. Valve sizeDN50-DN600Pressure rating ...