Patent ID: 7650905
Filing Date: 2010-01-26
Classification: F16K,Y10T

Abstract:
1. An emergency isolation valve apparatus comprising: a valve body having a valve plug and connected to a pipeline; a valve shaft connected to the valve plug of the valve body; a single-acting hydraulic cylinder having a piston urged by a spring and engaged with the valve shaft, pressurized fluid being supplied into the cylinder so that the piston is pressed to one end of the cylinder to allow the valve plug to open fully and being discharged in emergency so that the piston is moved to the other end of the cylinder to allow the valve plug to close fully; a discharge hole through an circumferential wall of the cylinder, the hole being closed by the piston when the piston moves from full-open position to allow the valve plug to close at a predetermined degree; a supply pipe for supplying the pressurized fluid into the cylinder; a discharge pipe connected to the discharge hole of the cylinder; a fluid control connected to the supply pipe and the discharge pipe to allow the fluid in the cylinder to be discharged until the piston closes the discharge hole, said fluid control comprising a normally-opened selector valve on the supply pipe and a normally closed selector valve on the discharge pipe, the normally-opened selector valve being closed and the normally-closed selector valve being opened so that fluid in the cylinder is discharged; and an emergency isolation selector valve disposed between the normally-opened selector valve and the hydraulic cylinder and configured to stop the supply of the pressurized fluid into the cylinder.