Isolating valve

摘要

An isolating valve includes a body having a canal for the passage of fluid, which is intended to be shut off by upstream and downstream spherical plugs, that can be actuated independently of one another between positions allowing the passage of fluid through the canal and positions of shutting off the canal, and a sealing checker, opening into the canal and between the two spherical plugs. The upstream plug is equipped with an upstream seat of the “simple piston effect” type and has no downstream seat. The downstream plug is equipped with an upstream seat of the “simple piston effect” type and with a downstream seat of the “double piston effect” type.

主权项

1. An isolation valve comprising a body including a fluid flow channel, adapted to be plugged by upstream and downstream spherical plugs which can be actuated independently of one another between positions for fluid flow through the channel and closing positions of the channel, and a sealing checker leading into the channel and between the two spherical plugs, the spherical plugs being equipped with seats associated with an elastic return so as to bear sealingly against the spherical plugs around the channel, a dead volume being defined between an outer wall of each spherical plug and the body, outside of the fluid flow channel, each seat being adapted to be subjected to the pressure of the fluid located inside the channel and the pressure of the fluid contained in the dead volume, wherein the upstream spherical plug is equipped with an upstream seat and has no downstream seat, the downstream spherical plug being equipped with an upstream seat and a downstream seat, the upstream seats being able to separate from the spherical plugs in the event of overpressure inside the corresponding dead volumes, and the downstream seat being adapted to remain to bear sealingly against the downstream spherical plug in the event of overpressure inside the corresponding dead volume.