摘要 |
A low pressure actuator for use in a dry, low-pressure, pressurized-gas, fire control and suppression sprinkler system for delivering an extinguishing liquid to a fire, wherein there is a system gas pressure of up to about 20 psi and an extinguishing liquid supply pressure of up to about 160 psi is disclosed. When actuated by a rapid fall in the system gas pressure, the device allows liquid to flow through to a sprinkler check valve, which, in turn, is actuated and provides liquid flow for distribution through a piping system to a plurality of interconnected sprinklers. One preferred embodiment of the device includes a multi-chambered housing having a gas compartment and a liquid compartment; means for initially pressurizing the gas compartment; a first flexible and moveable diaphragm, acting as a gas-liquid barrier, with one side in fluid communication with gas and a second side in fluid communication with the liquid; a second flexible, moveable diaphragm, acting as a water flow barrier, such that when the device is in a closed, ready-condition, a first side of the second diaphragm is in a wet state, and a second side of the second diaphragm is in a dry state, in communication with the liquid outlet. When the device is in an actuated condition, both sides of the second diaphragm are in a wet state, in contact with the liquid. When gas pressure in the sprinkler system drops below a pre-determined set point, pressure equilibrium on the first diaphragm is upset causing the first diaphragm to move and allow a priming flow of liquid to the liquid outlet through a liquid by-pass, which is otherwise sealed when the first diaphragm is in a gas-liquid pressure equilibrium condition. This also simultaneously causes the second diaphragm to move and allow a greater flow of liquid to provide the main extinguishing liquid through to the liquid outlet.
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