Patent Application
20080128033
The present invention relates generally to a pressure relief check valve and, more particularly, to a pressure relief check valve with an adjustable opening pressure.
Pressure relief check valves are used in myriad systems and, as is generally known, are used to selectively relieve fluid pressure in a system or component of a system, if the fluid pressure therein attains a predetermined pressure value. One particular system that may include one or more pressure relief check valves is an aircraft environmental control system (ECS). Aircraft ECSs typically include relatively low-pressure distribution ducts and, as such, may additionally include high-flow pressure relief and reverse flow pressure protection devices.
In order to provide the desired relief and reverse flow protection functionalities, some ECSs include a pneumatic relief check valve using a poppet, a spring, and/or other moving parts. These valves, while generally safe, reliable, and robust, may experience pressure loss, may be larger or heavier than is optimal in certain situations, and/or may have moving parts that experience wear and/or exhibit less than perfect precision after repeated use.
Accordingly, there is a need for a device that provides adequate pressure relief and reverse flow protection that reduces pressure loss and/or wear, increases precision and/or durability, is smaller in size and/or weight, and/or uses fewer moving parts, as compared to presently known devices. The present invention addresses one or more of these needs.
The present invention provides an adjustable pressure relief check valve.
In one embodiment, and by way of example only, the adjustable pressure relief check valve comprises a valve body, a flapper, a magnet, and an adjustment mechanism. The valve body has an upstream side, a downstream side, and a flow channel that extends between the upstream and downstream sides. The flapper is rotationally mounted on the valve body, and is movable between a closed position, in which the flapper at least substantially seals the flow channel, and an open position, in which the flapper unseals the flow channel. The magnet is coupled to the flapper. The adjustment mechanism comprises a magnetically permeable material, and is movably coupled to the valve body at a position in which the adjustment mechanism is magnetically attracted to the magnet with a magnetic closing force at least when the flapper is in the closed position, to thereby at least substantially inhibit flapper movement from the closed position. Movement of the adjustment mechanism varies the magnetic closing force.
In another embodiment, and by way of example only, the adjustable pressure relief check valve comprises a valve, a flapper, and an adjustable magnet. The valve body has an upstream side, a downstream side, and a flow channel that extends between the upstream and downstream sides. The flapper is rotationally mounted on the valve body, and is movable between a closed position, in which the flapper at least substantially seals the flow channel, and an open position, in which the flapper at least substantially unseals the flow channel. The flapper comprises a magnetically permeable material. The adjustable magnet is movably coupled to the valve body at a position in which the adjustable magnet magnetically attracts the magnetically permeable material with a magnetic closing force at least when the flapper is in the closed position, to thereby at least substantially inhibit flapper movement from the closed position.
In yet another embodiment, and by way of example only, the adjustable pressure relief check valve comprises a valve body, a flapper, and an adjustment mechanism. The valve body has an upstream side, a downstream side, and a flow channel that extends between the upstream and downstream sides. The flapper is rotationally mounted on the valve body, and is movable between a closed position, in which the flapper at least substantially seals the flow channel, and an open position, in which the flapper unseals the flow channel. The flapper includes a magnet. The adjustment mechanism comprises a magnetically permeable material, and is movably coupled to the valve body at a position in which the adjustment mechanism is magnetically attracted to the magnet with a magnetic closing force at least when the flapper is in the closed position, to thereby at least substantially inhibit flapper movement from the closed position. The movement of the adjustment mechanism varies the magnetic closing force.
Other independent features and advantages of the preferred systems will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
The following detailed description of the invention is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description. In this regard, although the invention is described herein as being implemented in an air distribution system, it will be appreciated that it could also be implemented in any one of numerous other types of systems that direct the flow of various types of fluid, both within or apart from an aircraft, and/or any one of numerous other types of vehicles or other types of apparatus or systems.
The pressure relief check valve 110 is configured to control the air flow through the outlet duct 106, to release pressure in the air distribution system if it exceeds a predetermined amount, and to prevent the air from flowing in a reverse direction. The pressure relief check valve 110 is preferably configured to exhibit a minimal pressure drop. In a particular preferred embodiment, the pressure relief check valve 110 is implemented using a check valve. A first exemplary embodiment of the pressure relief check valve 110 is depicted with various views in
Turning first to
The flappers 204 are each rotationally mounted on the valve body 202, and are movable between a closed position and a full-open position. In the depicted embodiment this is accomplished be rotationally mounting each flapper 204 onto the hinge pins 216 via integral lugs 215. No matter the specific manner in which the flappers 204 are rotationally mounted, in the closed position, the flappers 204 engage a seat region 219 on the valve body 202 to seal, or at least substantially seal, a corresponding flow channel 212. In the full-open position, or any one of numerous open positions between the closed and full-open positions, the flappers 204 unseal the corresponding flow channels 212. Thus, when the flappers 204 are in the closed position, fluid flow through the flow channels 212 is prevented, or at least substantially inhibited, and when the flappers 204 are in an open position, fluid flow through the flow channels 212 is allowed. Rotational movement of the flappers 204 is limited by the stop tube 218.
The pressure relief check valve 110 is preferably configured such that both flappers 204 are simultaneously in either the closed or an open position. However, as will also be described further below, this is merely exemplary of a particular embodiment, and the pressure relief check valve 110 could be configured such that each flapper 204 may be individually moved to an open or closed position. Moreover, although the pressure relief check valve 110 is preferably implemented with a pair of flow channels 212 and an associated pair of flappers 204, it will be appreciated that the pressure relief check valve 110 could, in an alternative embodiment, be implemented with more or less than this number of flow channels 212 and/or flappers 204.
Each of the magnets 206, at least in the depicted embodiment, is coupled to a corresponding flapper 204. The magnets 206 are preferably permanent magnets such as rare earth magnets, although different types of magnets may be used. Each magnet 206 may be coupled to its corresponding flapper 204 using any one of numerous techniques, and in any one of numerous locations on, or within, its corresponding flapper 204. The manner in which each magnet 206 may be coupled to its corresponding flapper 204 is discussed further below. Preferably, however, the magnet 206 is disposed at a location coincident with the section of the flapper 204 that engages the valve body seat region 219 when the flappers 204 are in the closed position.
Each of the adjustment mechanisms 207 is made from a magnetically permeable material, such as a magnetic steel. Each adjustment mechanism 207 is coupled to the valve body 202 at a position that preferably corresponds with one of the magnets 206. Thus, each adjustment mechanism 207 is magnetically attracted to one of the magnets 206 with a magnetic closing force at least when the corresponding flapper 204 is in the closed position, to thereby prevent, or at least substantially inhibit, movement of the flappers 204 from the closed position. Preferably, each flapper 204 is configured to receive a variable inlet pressure from a non-illustrated inlet pressure source in a direction opposite the direction of the magnetic closing force, thereby moving the flapper 204 to the open position when the variable inlet pressure exceeds the magnetic closing force. When the flapper 204 begins moving to the open position in this manner, the magnetic closing force is rapidly reduced, thereby allowing opening of the flapper 204 to the full-open position with enhanced precision and reduced pressure loss.
As shown in
Also as shown in
Turning now to
In the second embodiment depicted in
Moving the adjustment mechanism 207, or the adjustable magnet 238 thereof, varies the distance 226 between the adjustable magnetic 238 and the magnetic portion 236 when the flapper 204 is in the closed position and concomitantly varies the magnetic closing force. Accordingly, the opening pressure of the valve 110 can be adjusted by moving the adjustment mechanism 207 or the adjustable magnet 238 thereof. As mentioned above, the valve 110 in this second embodiment otherwise operates in a similar fashion as the first embodiment discussed above.
The pressure relief check valve 110 provides a number of potential benefits. For example, the use of magnets 206 and corresponding adjustment mechanisms 207 (or the use of magnetic portions 236 and corresponding adjustable magnets 237) allows for calibration of the opening pressure and operation of the pressure relief check valve 110 with improved precision, opening of the flappers 204 to the full-open position on a more consistent basis, reducing space, weight, cost, and/or reliance on moving parts, increasing reliability and/or durability, and/or minimizing pressure loss.
It will be appreciated that the pressure relief check valve 110, and/or various components thereof, may also include any one or more of a number of different variations from the exemplary embodiments depicted above. It will similarly be appreciated that the pressure relief check valve 110 can be used in any one of numerous different types of systems 100.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt to a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
