BODY
The body is in carbon or stainless steel and is also available in many other CRA. It is carefully designed for total reliability, to keep the pressure drops to a minimum and simple maintenance. The basic dimensions, wall thickness, face to face and flanges, comply with the relevant BS, API and ASME standards. The body neck is cylindrical in order to host the pressure seal bonnet. The seat is welded-in as a standard or is threaded upon request. Two flanged hubs are provided for the location of the hinge pins. Bosses are eventually provided for drain threaded connection.
COVER
The cover is in forged or cast steel. It is cylindrical, generally machined from bar-stock material and accommodates a conical surface for body gasket seating at the lower peripheral edge. A locking flange with a set of bolts pulls the cover outward, against the gasket, giving a preload for initial sealing.
DISC
The tilting disc is part of the trim. It is generally supplied as cast, machined from bar material for small sizes (up to 2”). The disc’s balanced design allows to keep it in the open position by a minimum fluid flow and lets this one to return to closed position quickly, before flow reversal starts, and so far not causing a sudden water hammer effect (non slam effect). The conical seating surface is ground and lapped.
PRESSURE SEAL RING
It is basically supplied in graphite for best fit up to class 1500 and in AISI 316L stainless steel for 2500, carefully machined to provide a perfect tight seal. Upon request, AISI 316L can be installed on every pressure rating.
HINGE PIN
The disc pins are part of the trim. They are in forged stainless steel machined from ground bar. The disc pins are held in position with two small blind flanges and they can be easily removed for valve maintenance.