Q-fuse, LLC

Parker-hannifin Corporation

Robert P Smith

Hubert Q Stedman

Gerald G Steele

A fluid flow fuse has a body, which includes an inlet and an outlet with a valve seat therebetween. A valve stem having a valve member thereon is mounted in the body, and the valve member is operably connected to a diaphragm, which separates a region within the body into a pair of separate pressure chambers. Fluid passages are formed in the body communicating the separate pressure chambers with downstream pressure from the outlet and upstream pressure from the inlet. The pressure differential between the chambers is minimized so that at least one spring will normally hold the valve member in an open position, until the pressure differential reaches a predetermined amount, whereby the valve member is slowly and smoothly closed until fluid flow through the fuse is stopped. The valve seat and valve member do not form a perfectly tight seal, so as to allow some leakage, thereby allowing restricted fluid flow into the downstream side of the fuse and any system connected thereto, to equalize upstream and downstream pressures, which allows the valve to reset itself. Different types of valves, namely, sleeve valves and poppet valves, are used for different embodiments.

Fluid flow fuse

A fluid flow device has a body which includes an inlet and an outlet with a valve seat therebetween. A valve stem having a valve member thereon is mounted in the body, and the valve member is operably connected to a diaphragm which separates a region within the body into a pair of separate pressure chambers. A fluid passage is formed in the body communicating one pressure chamber with upstream pressure in the inlet, while the other pressure chamber communicates with downstream pressure in the outlet. A pressure differential between the chambers will normally hold the valve member in an open position against the action of a biasing means, until the pressure differential reaches a predetermined amount, whereby the valve member is slowly closed until fluid flow through the device is stopped. The valve seat and valve member do not form a perfectly tight seal so as to allow some leakage thereby allowing restricted fluid flow into the downstream side of the device and any system connected thereto, to prevent the system from being emptied.

A temperature controlled regulator in which valved air inlets communicated with air pressure sources at different temperatures control the flow of air into a mixing chamber to maintain the outlet temperature of the mixture within specified limits, said regulator being characterized in that the valve actuator has first and second chambers on opposite sides thereof respectively exposed to the pressure of the mixture and to a reduced air pressure between the downstream side of a variable area orifice controlled by a temperature sensor in the regulator outlet and the upstream side of a variable area pressure control or bleed orifice, the first-mentioned variable area orifice being decreased or increased in size by decrease or increase of the mixture temperature with reference to said specified value thus to vary the pressure in said second chamber in relation to the pressure acting in said first chamber to inversely vary the air flow through said inlets thus to maintain a specified temperature of the mixture. The regulator herein is further characterized in that the temperature sensor comprises elongated members which have different coefficients of linear thermal expansion arranged so that, upon increase in temperature of the air mixture, a valve member engaged with the member having the lower coefficient is moved away from a seat member to increase the size of the variable area orifice and so that, upon decrease of the temperature of the mixture, said valve member is moved toward the seat to decrease the size of the variable area orifice, said seat member being yieldable upon engagement by the valve member to prevent damage to the valve member or to the seat member upon yet further decrease of the mixture temperature or during periods of non-use of the regulator.

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Lake Forest, CA, United States of America

Robert P Smith