The present invention relates to a submersible turbine pump, and more particularly relates to a submersible turbine pump having an improved yoke assembly.
In service station environments, fuel is delivered to fuel dispensers from underground storage tanks (UST), sometimes referred to as fuel storage tanks. USTs are large containers located beneath the ground that contain fuel. A separate UST is provided for each fuel type, such as low octane gasoline, high-octane gasoline, and diesel fuel. In order to deliver the fuel from the USTs to the fuel dispensers, a submersible turbine pump (STP) is provided that pumps fuel out of the UST and delivers the fuel to fuel dispensers through a main fuel piping conduit that runs beneath the ground in the service station.
A typical STP is illustrated in U.S. Pat. No. 6,223,765. As illustrated in
To access the wiring 296, the removable top 22 and the yoke 300 must be removed from the casing body 12. The top 22 is removed by removing the bolts 34, and the packer is removed by removing the bolt 302 from the lug 304. Therefore, there remains a need for a STP having an improved packer and yoke that simplifies the process of gaining access to the electrical wiring within the STP.
The present invention provides a submersible turbine pump (STP) comprising a manifold, a yoke assembly including a yoke sleeve integrally connected to the manifold, and a packer removably secured to the manifold. In general, the manifold includes an electrical cavity that receives electrical wiring from an external source, such as a power source and controller. The yoke sleeve has a hollow interior and is integrally connected to manifold such that a first end of the yoke sleeve is inserted into the electrical cavity. The packer includes a wiring chamber having a yoke sleeve inlet port and an electrical conduit inlet port. The yoke sleeve inlet port receives a second end of the yoke sleeve extending from the manifold, and the electrical conduit inlet port receives an electrical conduit extending from a pump within an associated underground storage tank. The electrical wiring from the external source passes from the electrical cavity in the manifold to the wiring chamber in the packer through the yoke sleeve and from the wiring chamber to the pump through the electrical conduit.
When the packer is removed from the manifold, the yoke assembly operates to automatically sever the electrical wiring at a critical point. By automatically severing the electrical wiring when the packer is removed, the yoke assembly ensures that any gas vapors that may enter the electrical cavity upon removing the packer are not ignited by a spark from exposed wiring.
The electrical wiring is brought into the electrical cavity in the manifold through a field wiring conduit. The electrical chamber in the manifold may be sealed to form an explosion proof chamber. In one embodiment, a rubber bushing is placed within the field wiring conduit, and the electrical wiring passes through the bushing into the electrical cavity. Plates are located above and below the rubber bushing and operate to adjustably compress the rubber bushing to provide strain relief to the electrical field wiring. One or more screws pass through the plates such that when the screws are tightened, the plates compress the rubber bushing. When the screws are loosened, the compression of the rubber busing is relieved.
Those skilled in the art will appreciate the scope of the present invention and realize additional aspects thereof after reading the following detailed description of the invention in association with the accompanying drawing figures.
The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the invention, and together with the description serve to explain the principles of the invention.
The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the invention and illustrate the best mode of practicing the invention. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the invention and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims.
Before describing the particular inventive aspects of the STP 10 contained in this patent application in detail, a continued overview of the various components of the STP 10 is illustrated in
The casing body 12 has a top 18, also called a “packer,” that is normally closed. The casing body 12 is also comprised of a manifold 19. The packer 18 fits on top of the manifold 19 to form a tight seal when the STP 10 is its normal configuration. The packer 18 can be removed if the STP 10 needs to be serviced. If the STP 10 needs to be serviced by gaining access to the internal hydraulics cavity 20 (illustrated in
After the nuts 22 are loosened by rotating them counterclockwise, the packer 18 can be removed from the manifold 19 by applying a pulling force to a handle 24 that is secured to the packer 18. The handle 24 has a curly shaped head 26 that is designed to allow a rope or chain to be placed inside an orifice 28 formed by the head 26 to apply such force. When the packer 18 is placed on body 12 on top of the manifold 19 and the nuts 22 are tightened, the casing 12 is fluid tight. The packer 18 is removable so that access can be obtained to the internal hydraulics cavity 20 of the STP 10.
The manifold 19 contains an integral contractors box 29 that allow a service personnel to gain access to electrical cavity 30 (illustrated in
The STP 10 also contains a check valve extraction housing 36 that allows extraction of a check valve 38 (illustrated in
The manifold 19 contains two siphon connections 42 that provide a siphon system. The siphon connections 42 are designed to receive a siphon cartridge 44 to provide coupling to a vacuum created inside the STP 10 via a nozzle 102 (illustrated in
After a while, the o-rings 49 swell when exposed to fuel inside the manifold 19 thereby increasing the friction between the packer 18 and the manifold 19 if separated. Before the present invention, this causes a great deal of force to have to be exerted on the handle 24 to remove the packer 18 from the manifold 19 to gain access to the hydraulic cavity 20.
In the present invention, the manifold 19 includes two female pockets 50 that are located directly beneath the nuts 22 that secure the packer 18 to the manifold 19. Die springs 52 are placed inside each of the two female pockets 50 while the packer 18 is removed during manufacturing or servicing of the STP 10. Springs 52 are selected so that the springs 52 extend beyond the top of upper plane 54 of the manifold 19 when not under any compression. When the packer 18 is placed on top of the manifold 19, and the nuts 22 are tightened to seal the packer 18 to the manifold 19, the springs 52 are compressed inside the pockets 50 causing the springs 52 to store energy. When service personnel desires to remove the packer 18 from the manifold 19, the service personnel applies a pulling force to the packer 18, usually via the handle 24 after the nuts 22 are loosened. The die springs 52, under compression, are exerting a force against the packer 18 so that less pulling force is required to be applied to the handle 24. In essence, as the packer 18 is pulled upward, the energy stored in the springs 52 is also exerting force upward against the packer 18 thereby aiding in the removal of the packer 18 from the manifold 19.
The inclusion of die springs 52 in the manifold 19 is an improvement over prior STP 10 designs that provide the ability to remove a packer 18 from the manifold 19. Depending on the springs 52 selected and the amount of energy stored in the springs 52 when compressed, when the packer 18 is sealed onto the manifold 19, the springs 52 may even contain enough stored energy to separate the packer 18 from the manifold 19 after the nuts 22 are loosened without any pulling force being applied on the handle 24. Before inclusion of the die springs 52, a larger amount of force had to be applied to the packer 18 to remove it from the manifold 19 especially since the o-ring seals 49 provide a pressurized seal between the packer 18 and the manifold 19 requiring high extraction/separation forces to remove the packer 18 from the manifold 19 for servicing.
Any type of spring may be used as the springs 52. Further, even though the current design of the STP 10 includes two springs 52, only one spring 52 and pocket 50 combination may be used, or more than two springs 52 and pocket 50 combinations may be used. It may be more advantageous to provide only one spring 52 for space conservation so long as a single spring 52 can store enough energy to aid in the extraction of the packer 18 from the manifold 19. According to one embodiment of the present invention, the springs 52 are Raymond® die springs manufactured by Associated Spring.
Another aspect of the STP 10 that is a subject of this application is an improved yoke assembly 56 illustrated in
Turning to
It is necessary for safety reasons to ensure that the electrical wires 58 that connect to the turbine pump (not shown) are disconnected from the electrical wires 58 that run inside the conduit 62 in the yoke sleeve 60 if the packer 18 is removed from the manifold 19. When the packer 18 is removed, the electrical wires 58 are broken at the critical point 70. In prior art systems, the yoke assembly was a separate device from the STP 10, like in aforementioned U.S. Pat. No. 6,223,765 B1. The yoke was provided in an explosion proof housing in case a spark were to occur at the joint where an electrical connection is made between the yoke and packer. In this prior art system, service personnel had to first remove the yoke assembly separately before gaining access to the hydraulics cavity 20 to remove the pump via removal of the packer. Now with the present invention, service personnel only need to remove the packer 18 to automatically sever the electrical wires 58 when the packer 18 is removed from the manifold 19 since the yoke assembly 60 is integral with the manifold 19 and not the packer 18.
The STP 10 also contains an integral contractors box 29 comprised of one or more electrical cavities 30. In the example illustrated in
When service personnel make wiring connections necessary to put the STP 10 into service in the field, the service personnel bring the wiring into the electrical cavities 30 via the field wiring conduit 74 in
When service personnel later want to access the field wiring without breaking the seal formed at the field wiring conduit 74 underneath the manifold 19, the service personnel can loosen the plugs 34 to gain access to the electrical cavity 30. The plugs 34 seal the electrical cavity 30 off and o-rings 76 are provided between the plugs 34 and the threaded ports 37 to form a tight seal when the plugs 34 are tightened.
One reason that an electrical cavity 30 is provided that contains two plugs 34 for access in the STP 10 is that a capacitor 78 is included inside the electrical cavity 30 in this example. A capacitor 78 may be used to store energy to assist the motor (not shown) in the STP 10 when a fuel dispenser is activated to dispense fuel. Please note that the capacitor 78 is an optional component and is not required.
As discussed above, the rubber bushing 82 within the field wiring conduit 74 is compressed between the two steel plates 80 on the top and bottom of the rubber bushing 80. The screws 84 are tightened and the bushing 82 is compressed to provide strain relief to the electrical wiring 58. It should also be noted that the steel plates 80 have multiple holes through which individual wires of the electrical wiring 58 pass. As illustrated, the two steel plates 80 include five holes. Since there are only three wires in the electrical wiring 58, two of the holes are plugged by plugs 85.
When the STP 10 is serviced, the STP 10 is shut off and the service personnel must remove the packer 18 to pull out the pump in the hydraulic cavity 20 for servicing. However, after the STP 10 is turned off, there is still residual pressure trapped in the pipeline when the check valve 38 is closed since fuel will no longer flow to keep the check valve 38 opened. There is a differential pressure between the outlet side 88 of the check valve 38, which is hydraulic cavity 90, and atmosphere. If the check valve housing 36 is removed by service personnel to gain access to the check valve 38, the pressure build up on the outlet side 88 of the check valve 38 will equalize with atmosphere (or the pressure on the outside the STP 10) and fuel will possibly spill outside of the manifold 19 and STP 10 to the environment and possibly make contact with the service personnel. The present invention provides the ability to depressurize the outlet side 88 of the check valve 38 before the check valve 38 is serviced by actuation of a lock down screw 92, which has not been done before the present invention.
Depressurization of the check valve 38 is accomplished by placing a tool inside receptacle 94 and rotating the receptacle 94 which lowers the lock down screw 92 on the check valve stem 98 illustrated in
The lock down screw 92 also allows the check valve 38 to be locked into position when fuel supply piping is checked for leaks during installation and on service calls. When the check valve 38 is locked into a closed position, the STP 10 effectively cannot release pressure. This effectively isolates the STP 10 from the fuel supply piping that connects the STP 10 to the fuel dispensers for delivery of fuel. It may be desired for service personnel to pressurize and test the fuel supply piping to ensure that no leaks are present. With the present invention, service personnel can use the STP 10 to lock down the check valve 38 to isolate the STP 10 from the fuel supply piping. In this manner, if a leak is detected when pressurizing and testing the fuel supply piping for leaks, the STP 10 can be eliminated as the source of the leak since it is isolated from the fuel supply piping.
The vacuum created by the siphon connection cartridge 44 may be used for a number of purposes. For instance, the vacuum may be used to siphon two underground storage tanks together, as is shown and described in U.S. Pat. No. 5,544,518 entitled “Apparatus and Method for Calibrating Manifolded Tanks,” incorporated herein by reference in its entirety. The vacuum may also be used to generate a vacuum in a defined space for leak detection purposes. For example, pending patent application Ser. No. 10/238,822 entitled “Secondary Containment System and Method;” Ser. No. 10/430,890 entitled “Secondary Containment Leak Prevention and Detection System and Method;” and Ser. No. 10/390,346 entitled “Fuel Storage Tank Leak Prevention and Detection,” all of which are incorporated herein by reference herein in their entireties, and disclose pressure monitoring and leak detection systems where a vacuum generated by the STP 10 is used to generate a vacuum in an interstitial space, including but not limited to a double-walled underground storage tank interstitial space, the interstitial space of double-walled fuel piping.
Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present invention. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow.
This application claims priority to Provisional Patent Application Ser. No. 60/510,735 filed on Oct. 11, 2003, which is hereby incorporated by reference in its entirety. This application is related to the following commonly owned U.S. Patent Applications, which are hereby incorporated by reference in their entireties: i) U.S. patent application Ser. No. ______, entitled “Spring Loaded Submersible Turbine Pump”, filed on ______, ii) U.S. patent application Ser. No. ______, entitled “Integral Contractors Box For A Submersible Turbine Pump”, filed on ______, iii) U.S. patent application Ser. No. ______, entitled “Check Valve for a Submersible Turbine Pump”, filed on ______, and iv) U.S. patent application Ser. No. ______, entitled “Siphon System For A Submersible Turbine Pump That Pumps Fuel From An Underground Storage Tank”, filed on ______.
Number | Date | Country | |
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60510735 | Oct 2003 | US |