Pipe line non return valve - has adjustable apertured liner enabling repairs without plant shut down

摘要

Closure valve, particularly a non return valve, provided with a housing (1) which has an inlet (2) and an outlet (3), and a closure ball (4) within the housing. The housing has an aperture closable by a cover (5). In the housing, there is a lining (6) which has openings (7,8) which, in the rest position of the lining, are aligned with the inlet and the outlet, whilst the lining n6) is adjustable to an effective position, in which it closes the inlet and the outlet (7,8) whereby the interior of the lining is accessible via the cover (5).