Patent ID: 6708784
Filing Date: 2004-03-23
Classification: E21B

Abstract:
A method for a valve, which valve comprises a movable valve body having a first side facing a means for supplying pressurized fluid and influenced in the supply direction by a force from said fluid, and a second side influenced in opposite direction by a force from said fluid, which valve is provided with at least one fluid connection connecting the first side of the valve body with the second side of the valve body and thereby allowing said supplied pressurized fluid to flow from said first side to said second side of the valve body, and also comprising a spring for opening the valve by displacing the valve body from a closed position to an open position, said method comprising the following steps:a pressurized fluid is supplied to the valve in closed position whereupon the valve remains closed, the supply of pressurized fluid to the closed valve ceases, a force equalization then occurs between said first and second sides in that fluid flows through the fluid connection, thereby enabling the spring to open the valve, and a pressurized fluid is supplied to the valve in open position and the valve remains open.