Abstract: A relief valve includes a first chamber with an inlet that includes an inlet valve seat and an outlet. A second chamber is spaced apart from the first chamber. A chamber wall is positioned between the first chamber and the second chamber. A closure member is movably positioned within the first chamber and is configured to be closable on the inlet valve seat. A first magnet is coupled to the closure member. The first magnet is movably positioned within the second chamber and is configured to generate a first magnetic field of a first polarity. A second magnet is positioned within the second chamber and is configured to generate a second magnetic field of a second polarity. The first magnetic field and the second magnet field interact to bias the closure member to rest on the inlet valve seat with a set force.

Abstract: A safety relief valve is provided that comprises a body comprising a chamber therein and an inlet and an outlet, the inlet comprising an inlet valve seat; a disk member closable on the inlet valve seat; and a mechanism in the body biasing the disk member to rest on the inlet valve seat with a set force such that when the pressure in the inlet exceeds a set pressure resulting from the set force, the disk member is lifted from the inlet valve seat, the mechanism comprising a combination of a coil spring and one or more disk springs stacked in series with the coil spring. A method of preparing a coil spring for use in a pressure relief valve comprises measuring the spring rate of the coil spring and; modifying the spring so as to modify its spring rate to be within ±2% of a desired spring rate.

Abstract: A safety relief valve is provided that comprises a body comprising a chamber therein and an inlet and an outlet, the inlet comprising an inlet valve seat; a disk member closable on the inlet valve seat; and a mechanism in the body biasing the disk member to rest on the inlet valve seat with a set force such that when the pressure in the inlet exceeds a set pressure resulting from the set force, the disk member is lifted from the inlet valve seat, the mechanism comprising a combination of a coil spring and one or more disk springs stacked in series with the coil spring. A method of preparing a coil spring for use in a pressure relief valve comprises measuring the spring rate of the coil spring and; modifying the spring so as to modify its spring rate to be within ±2% of a desired spring rate.

Abstract: A safety relief valve is provided that comprises a body comprising a chamber therein and an inlet and an outlet, the inlet comprising an inlet valve seat; a disk member closeable on the inlet valve seat; and a mechanism in the body biasing the disk member to rest on the inlet valve seat with a set force such that when the pressure in the inlet exceeds a set pressure resulting from the set force, the disk member is lifted from the inlet valve seat, the mechanism comprising a combination of a coil spring and one or more disk springs stacked in series with the coil spring. A method of preparing a coil spring for use in a pressure relief valve comprises measuring the spring rate of the coil spring and; modifying the spring so as to modify its spring rate to be within ±2% of a desired spring rate.

Abstract: A snap-type safety relief valve is provided that is designed for use under specified operating conditions on a pressure vessel or a flow line having a pressurized gas therein.