Patent ID: 8365764

Claim:
Minimum pressure valve, comprising: a housing with an inlet and an outlet, said inlet and outlet being connected via an inner duct system; a movable valve body in the inner duct system being arranged to be pressed against a seating surface around the inlet in a first, closed position, wherein a spring is used to press said movable valve body against said seating surface to close off the inlet and said valve body being arranged to be disposed at a distance from the seating surface in a second, open position, such that the inner duct system connects the inlet to the outlet; a valve casing fixed in the inner duct system within the housing, said valve casing comprising a cylindrical housing having an end wall arranged to form a closed end, an open end on an opposite end of the cylindrical housing, and a cylindrical chamber disposed between the closed end and the open end, wherein said cylindrical chamber and movable valve body form a confined, inner space; an internal duct extending through the movable valve body to connect the inlet of the housing to the confined, inner space; wherein the movable valve body comprises a piston part being arranged to move in a sliding manner within the cylindrical chamber of the valve casing, a sealing element arranged to be pressed against the seating surface in the closed position of the movable valve body, and a valve stem arranged to connect the piston part to the sealing element; said piston part being in the shape of a cylindrical bush and comprising a lower wall arranged to substantially seal the cylindrical bush on at least one side apart from said internal duct, wherein said spring extends at least partly within the cylindrical bush to the lower wall; said lower wall having a cylindrical fixing wall extending inwardly towards the confined, inner space, said cylindrical fixing wall being arranged to accommodate the valve stem in a partly fixed or movable manner, and said internal duct extends through the cylindrical fixing wall of the lower wall, the valve stem, and the sealing element to connect the inlet to the confined, inner space.