Line removable valve structure with extensible seal rings on pipeline support structure

Claim 1

In a line-removable valve structure comprising: a pipeline-support structure; and a valve cartridge received in said structure; said valve cartridge including: a body containing a movable valve closure member and end closures with flow openings therein; said support structure comprising: a pair of opposing end plates with flow passageways therethrough; means on the outboard sides of said end plates for connection thereof into a pipeline; and rigid steel side members interconnecting said end plates; means for sealing said valve cartridge between said end plates comprising: a support structure seat ring carried on the inner surface of an end plate; annular sealing means around the inwardly directed annular face of said seat ring; an opposing sealing surface on one of said cartridge end closures around a flow opening; complementary thread means on said seat ring and said end plate to move said seat ring along the axis of said flow passageway upon turning said seat ring through a rotational increment; selectively operable means for producing said rotational increment of said seat ring, said selectively operable means including: gear teeth at least partially around said seat ring; and complementary gear teeth on said support structure for movement thereon so as to enable removal of said valve cartridge.