Abstract: The invention relates to a pressure valve with a flow passage (3) having a valve body (14) and a lifting plate (21) that has a surface area A2 transversally of the flow passage (3) that exceeds the cross sectional area A1 of the flow passage (3) at the valve seat (13) of the valve body, said pressure valve being configured such that, at any time, the container is in communication with the area above the lifting plate (21). The invention is characterised in that the pressure valve also comprises a magnet (8) and a magnetisable body (9); and that the force of attraction Fm between the magnet (8) and the magnetisable body (9) and the mass of the lifting plate (21) contributes to defining the abutment force Fc, of the valve body (14) against the valve seat (13) in the closed state of the pressure valve.

Abstract: The invention relates to a pressure valve with a flow passage (3) having a valve body (14) and a lifting plate (21) that has a surface area A2 transversally of the flow passage (3) that exceeds the cross sectional area A1 of the flow passage (3) at the valve seat (13) of the valve body, said pressure valve being configured such that, at any time, the container is in communication with the area above the lifting plate (21). The invention is characterised in that the pressure valve also comprises a magnet (8) and a magnetisable body (9); and that the force of attraction Fm between the magnet (8) and the magnetisable body (9) and the mass of the lifting plate (21) contributes to defining the abutment force Fc, of the valve body (14) against the valve seat (13) in the closed state of the pressure valve.

Abstract: The invention relates to a vacuum relief unit for pressure equalisation between the ambient atmosphere and a tank in a tanker, wherein the vacuum relief unit comprises: a valve housing (10) with a first opening (12), whereby the valve housing (10) is able to communicate with the tank, and a second opening (24) with a seat (30) for a valve body (40) that is configured for being conveyable into the valve housing (10) to permit inflow of air to the tank; and a mechanism (100) configured for being able to prevent passage of seawater through the valve housing (10) in case of an accident, wherein the tanker is at least partially immersed into seawater, which mechansim (100) features a first movable part (160) that is arranged outside the valve housing (10) and whose movement can be controlled by the liquid pressure of the sea water, a second movable part (150) that can be advanced within the valve housing (10) and that is movably coupled to the first movable part (160).

Abstract: A pressure relief valve, e.g. for oil tankers comprising a valve housing, in the interior of which there is provided a valve seat for an upwardly opening valve body which carries a drop-shaped throttling member located in a flow-off opening at the top of the valve housing at a distance from the valve seat.