Inventors:
Jeremy Choate - Stafford TX, US
Michael Easton - Edmond OK, US
International Classification:
F16K017/20
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. The safety relief valve comprises: (a) a body attachable to the pressure vessel or flow line, the body comprising a chamber therein and an inlet and an outlet, the inlet comprising an inlet valve seat, the outlet being adapted to attach to outlet piping; (b) a disk member closable on the inlet valve seat; (c) 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 pressure vessel exceeds a set pressure resulting from the set force, the disk member is lifted from the inlet valve seat; and (d) a secondary orifice between the chamber and the outlet, the secondary orifice being sized so that gas flows from the inlet valve seat into the chamber in a sonic flow and so that gas flows from the chamber through the secondary orifice in a sonic flow when the valve opens due to a pressure in the pressure vessel or flow line exceeding the set pressure during testing under the specified operating conditions. A method of designing a low blow-down snap-type safety relief valve is provided, as is a method of relieving pressure from a pressurized system using a snap-type safety relief valve.