초록 ▼

A two-position pilot-operated SPM valve includes an improved cage for controlling fluid flow to a ram of a subsea blowout preventer. SPM valve 10 includes a piston 48 axially movable with respect to a valve body 12, a spool 38 for moving within the valve body between an open position and a closed po

A two-position pilot-operated SPM valve includes an improved cage for controlling fluid flow to a ram of a subsea blowout preventer. SPM valve 10 includes a piston 48 axially movable with respect to a valve body 12, a spool 38 for moving within the valve body between an open position and a closed position, and a piston rod 34 structurally interconnecting the spool and the piston. A cage 40 within the valve body receives the spool 38, and includes an axially intermediate body 84 formed from a selected plastic material, an upper body 86 removably secured to the intermediate body and having one or more radial throughports 106 therein, and a lower body 88 removably secured to the intermediate body. An external seal 92 is provided for sealing between the intermediate body and the valve body, an internal seal 96 provides dynamic sealing engagement between the intermediate body and the exterior cylindrical surface 72 of the spool. Interior cylindrical surface 100 of the intermediate body is in sliding engagement with the exterior spool cylindrical surface 72, and substantially reduces wear on the spool due to the plastic-to-metal sliding engagement of these surfaces. During servicing of the SPM valve, an intermediate body 84 may be replaced with a new intermediate body and both the upper and lower cage bodies installed on the new intermediate body. An improved technique is also provided for compressing the coil spring which biases the spool to the closed position.

대표청구항 ▼

[ what is claimed is:] [18.] A method of servicing a two-position pilot-operated valve including a valve body having a central valve axis, a fluid inlet port, and a fluid outlet port, a piston axially movable with respect to the valve body in response to, pilot pressure, a spool axially movable with

[ what is claimed is:] [18.] A method of servicing a two-position pilot-operated valve including a valve body having a central valve axis, a fluid inlet port, and a fluid outlet port, a piston axially movable with respect to the valve body in response to, pilot pressure, a spool axially movable within the valve body in response to axial movement of the piston, the spool being axially movable between an open position such that the inlet port is in fluid communication with the outlet port and a closed position such that the inlet port is blocked by the spool from fluid communication with the outlet port, a piston rod for structurally interconnecting the spool and the piston, a cage within the valve body for receiving the spool and including at least one radial upper throughport therein, an upper seal plate spaced axially between the cage and the piston for sealing engagement with the spool when in the closed position, a lower seal plate spaced axially between the cage and the fluid outlet port for sealing engagement with the spool when in the open position, and a spring to bias the spool toward the closed position, the method comprising:replacing a worn cage with another cage including an axially intermediate cage body formed from a selected plastic material;providing an external seal on the plastic material intermediate body for sealing between the intermediate body of the cage and the valve body and an internal on the plastic material intermediate body for continuous dynamic sealing between the cage and the spool during axial movement of the spool between the open and closed positions;removably securing an upper cage body including the one or more radial upper throughports therein to the intermediate body;removably securing a lower cage body to the intermediate body; andpositioning the another cage including the intermediate cage body, the upper cage body, and the lower cage body within the valve body such that an exterior surface on the intermediate body is in mating engagement with an interior surface on the valve body and an internal cylindrical surface of the intermediate body is in sliding engagement with an external cylindrical surface of the spool during axial movement of the spool between the open and closed positions.