Main steam isolation check valve

In a valve, the combination including a valve body with an annular valve seat about a passage therethrough, a disc-shaped valve member pivotally mounted relative to said valve seat, said disc-shaped valve member having a thickness which increases from the peripheral edge thereof toward the center of said valve member, said thickness being such that said disc-shaped valve member can deform as the valve member closes on said seat to absorb impact energy, a rockshaft means for pivotally mounting said valve member, said rockshaft means including link means connecting said rockshaft means to said valve member, said valve member having an axially extending pin loosely carried in an aperture in a hub on said link means so as to allow sidewise motion therebetween upon deformation of said valve means under high impact closing conditions, and a spring loaded yoke for securing said pin to said link means.

In a valve, the combination including a valve body with an annular valve seat about a passage therethrough, a disc-shaped valve member pivotally mounted relative to said valve seat, said disc-shaped valve member having a thickness which increases from the peripheral edge thereof toward the center of said valve member, said thickness being such that said disc-shaped valve member can deform as the valve member closes on said seat to absorb impact energy, a rockshaft means for pivotally mounting said valve member, said rockshaft means including link means connecting said rockshaft means to said valve member, said valve member having an axially extending pin loosely carried in said link means so as to allow motion therebetween upon deformation of said valve means under high impact, closing conditions, said link means having a hub thereon with an aperture therein loosely receiving said pin, and a spring loaded yoke for securing said pin to said link means, said spring loaded yoke including a shear plate mounted with shear pins on said hub so that cocking of said hub with respect to said disc-shaped valve member upon deformation of said disc-shaped valve member can shear a connection between said yoke and pin.

In a valve, the combination including a valve body with an annular valve seat about a passage therethrough, a disc-shaped valve member pivotally mounted relative to said valve seat, said disc-shaped valve member having a thickness which increases from the peripheral edge thereof toward the center of said valve member, said thickness being such that said disc-shaped valve member can deform as the valve member closes on said seat to absorb impact energy, the valve being a check valve and having a trip means connected to said disc-shaped valve member for maintaining the disc-shaped member in open position, said trip means including release means for releasing said valve member so that flow in a direction tending to close the valve will close the same, the trip means including a fluid pressure cylinder and piston operatively connected to said valve member, spring means within the cylinder urging the piston into position to allow closure of said valve, fluid pressure means acting upon said piston to maintain said valve member in open position under normal condition and such that venting of said fluid pressure means will cause said spring means to close said valve member, and rupture disc means within the cylinder for further venting said cylinder after a predetermined pressure is reached.

In a valve, the combination including a valve body with an annular valve seat about a passage therethrough, a disc-shaped valve member pivotally mounted relative to said valve seat, said disc-shaped valve member having a thickness which increases from the peripheral edge thereof toward the center of said valve member, said thickness being such that said disc-shaped valve member can deform as the valve member closes on said seat to absorb impact energy, a rockshaft means for pivotally mounting said valve member, said rockshaft means including link means connecting said rockshaft means to said valve member, said valve member having an axially extending pin loosely carried in said link means so as to allow motion therebetween upon deformation of said valve means under high impact closing conditions, and pin means between said yoke and hub preventing rotation therebetween.