Butterfly type stop valve - has recess in pipe wall accommodating protruding sealing ring vulcanised in place

摘要

The butterfly-type stop valve has a butterfly to match the pipe diameter turning on a spindle at right angles to the pipe axis. A recess (6) in the pipe wall contains a sealing ring (5) vulcanised into place, whose internal dia. is smaller than the dia. of the butterfly edge (11) and also than the internal dia. of the pipe. The outer edge of the butterfly can be slightly convex and it can be of slightly smaller dia. than the pipe.