초록 ▼

An air actuated valve system for shutting off fluid flow in a fluid conduit includes a seismic valve disposed in a seismic air circuit which is coupled to a primary air circuit. The primary air circuit delivers air at a high pressure to an air driven actuator which maintains a shut off valve in a fl

An air actuated valve system for shutting off fluid flow in a fluid conduit includes a seismic valve disposed in a seismic air circuit which is coupled to a primary air circuit. The primary air circuit delivers air at a high pressure to an air driven actuator which maintains a shut off valve in a fluid conduit in an open position. The high air pressure flows through an air switch which is operationally open and coupled to the seismic air circuit such that when the seismic valve is closed a pilot air pressure is prevented from flowing to the air switch. In the absence of the pilot air pressure, air pressure is bled from the air switch, causing the air switch to move from an open to a closed position, thus preventing air from flowing to the air actuator.

대표청구항 ▼

An air actuated valve system for shutting off fluid flow in a fluid conduit, comprising: a fluid shut off valve for placement in the fluid conduit; an air driven actuator, connected to the fluid shut off valve, for moving the fluid shut off valve between open and closed positions; a primary air circ

An air actuated valve system for shutting off fluid flow in a fluid conduit, comprising: a fluid shut off valve for placement in the fluid conduit; an air driven actuator, connected to the fluid shut off valve, for moving the fluid shut off valve between open and closed positions; a primary air circuit, in fluid communication with the air driven actuator, for supplying air to the air driven actuator at a pressure sufficient to maintain the fluid shut off valve in the open position; an air switch disposed in the primary air circuit upstream of the air driven actuator and being movable between open and closed positions; and seismic control means, connected to the air switch, for shutting off air to the air driven actuator in response to a predetermined level of seismic activity, said seismic control means comprising: a seismic air circuit, in fluid communication with the primary air circuit and the air switch, for supplying air to the air switch at a pressure sufficient to maintain the air switch in the open position, and a seismic valve disposed in the seismic air circuit for shutting off air supplied to the air switch in response to a predetermined level of seismic activity, thereby causing the air switch to close and thus the shut off valve to close.