Abstract: An safety valve includes a housing for defining a fluid flow passageway having a spring loaded seat body and spring mounted therein. The seat body is held in an open position by the spring and is composed of an elastomer material. According to the novel method of using the safety valve, when fluid flows against the seat body a resulting drag force causes the spring to compress. When the fluid flow reaches a predetermined excess flow rate level, the seat body sealingly engages the flow passage to substantially inhibit the flow of fluid except for a small by-pass flow passing downstream via a small channel disposed within the seat body.

Abstract: An safety shut off valve automatically shuts off in response to seismic or other shock wave forces of a predetermined magnitude and thereafter automatically reset when there is no discernible excess gas flow due a downstream broken or leaking pipe. The shut off valve generally includes a housing having a mass spring system mounted therein for translating lateral seismic and other shock forces exerted against the housing to an axially movable magnet for decoupling a valve member plate attracted thereto allowing it to block the downstream fluid communication path. A small bypass flow permits the valve member plate to be automatically reset in engagement with the magnet when the atmospheric pressure upstream of the plate is substantially equal to the atmospheric pressure downstream of the plate.