Stabilized valve

摘要

An SPM valve for use in a subsea environment includes a spool selectively movable between first and second positions to thereby arrange the valve in respective armed and disarmed configurations. The particular arrangement of a supply port and discharge port with respect to the spool permits a pressurized working fluid supplied to the supply port to bias the spool to both the first and second positions once an external force is applied to the spool to initially set the spool in either the first or second position.

主权项

1. A valve for use as a sub plate mounted valve in a subsea environment, the valve comprising:
a valve body defining an upper end, a lower end and an interior cavity therein, the interior cavity defining a longitudinal axis; a supply port extending laterally through the valve body and fluidly communicable with the interior cavity for supplying working fluid to the interior cavity; an upper valve seat disposed within the interior cavity; a lower valve seat disposed within the interior cavity; a discharge port extending axially through the lower end of the valve body and the lower valve seat, the discharge port fluidly communicable with the interior cavity for discharging working fluid from the interior cavity; a spool disposed within the interior cavity and selectively movable between an upper position wherein the spool is engaged with the upper valve seat to permit working fluid flow between the supply port and the discharge port and a lower position wherein the spool is engaged with the lower valve seat to prohibit working fluid flow between the supply port and the discharge port; a valve stem housing extending axially from the valve body, the valve stem housing having a piston chamber; a valve stem having a lower end that extends through a sealed opening into an interior of the spool, and a piston on an upper end of the valve stem and carried in the piston chamber; a down stroke pilot port extending into the piston chamber above the piston for providing a pilot down stroke fluid pressure to move the piston downward and the spool to the lower position; an upstroke pilot port extending into the piston chamber below the piston for providing a pilot up stroke fluid pressure to move the piston upward and the spool to the upper position; wherein the stem is free of any spring biasing the stem either upward or downward; the spool is configured to remain in the upper position in response to working fluid pressure in the interior of the spool once in the upper position in the absence of pilot up stroke fluid pressure; the spool is configured to remain in the lower position in response to working fluid pressure on an exterior of the spool once in the lower position in the absence of pilot down stroke fluid pressure; wherein the valve further comprises: a plurality of fins within the spool through which the stem extends; and an upper counterbore in the interior of the spool that extends downward from the upper end of the spool and has a lower end no lower than upper ends of the fins, to assist in retaining the spool in the upper position once in the upper position.