Patent ID: 7207350
Filing Date: 2007-04-24
Classification: F16K,Y10T

Abstract:
1. A pressure valve for ensuring a pressure equalization between a closed container, in particular a cargo hold or a tank on a maritime carrier, and the ambient atmosphere, and comprising a valve housing with: a wall that defines a flow passage with an upwardly oriented outflow mouthing for gas in the container, a valve body arranged at the outflow mouthing, said valve body having a surface part suitable for collecting a gas flow that flows through the flow passage and around the valve body to form an upwardly oriented jet, said valve body having a downwardly oriented valve face configured for abutting on an associated valve seat in the outflow mouthing of the valve housing in order to define a closed state of the pressure valve; a lifting plate being, relative to the valve seat, arranged further down in the flow passage, which lifting plate has a surface area A 2 transversally to the flow passage that exceeds the cross sectional area A 1 of the flow passage at the valve seat; wherein the lifting plate is connected to the valve body in order to allow them to be moved as an aggregate valve unit between said closed state and a state in which the pressure valve is open; and wherein the pressure valve is configured such that the container is, at any time, in communication with the area above the lifting plate; wherein the pressure valve also comprises a magnet and a magnetizable body, when in said closed state a distance between the magnet and the magnetizable body is variable; where the force of attraction F m between the magnet and the magnetizable body and the mass of the lifting plate contribute to defining the abutment force F c of the valve body against the valve seat in the closed state of the pressure valve, wherein the free through-flow area (A 3 –A 2 ) in the flow passage at the lifting plate constitutes between approximately 25% and about 55% of the area A 3 of the flow passage at the lifting plate.