1. A submersible pumping system comprising:
a body;
a piston axially moveable relative to said body between an extended position and a retracted position;
a pump valve coupled to said body and in fluid communication with a supply of operating fluid, wherein said pump valve has a first position wherein said pump valve supplies operating fluid so as to move said piston to the extended position and a second position wherein said pump valve supplies operating fluid so as to move said piston to the retracted position;
an upper stop coupled to said pump valve, wherein said pump valve is moved to the first position when said upper stop is engaged by said piston in the retracted position; and
a lower stop coupled to said pump valve, wherein said pump valve is moved to the second position when said lower stop is engaged by said piston in the extended position.
2. The submersible pumping system of claim 1, further comprising:
a pump housing coupled to said body;
a inlet valve that controls flow of fluid into said pump housing; and
an outlet valve that controls the flow of fluid out of said pump housing.
3. The submersible pumping system of claim 2, further comprising:
a diaphragm coupled to said pump housing so as to separate said pump housing into a working chamber and a pump chamber, wherein said piston is disposed within the working chamber and said inlet and outlet valves control the flow of fluid into and out of the pump chamber.
4. The submersible pumping system of claim 2, wherein said pump housing is coupled to said body by a flexible coupling.
5. The submersible pumping system of claim 1, wherein said pump valve comprises:
a valve housing coupled to said body; and
a valve spool comprising a center feed that supports said upper stop and said lower stop, wherein the center feed is partially disposed within said piston.
6. The submersible pumping system of claim 5, wherein said piston further comprises a flange that is disposed about the center feed between said upper stop and said lower stop, wherein said flange has an outer edge sealingly engaged with said body and all inner edge sealingly engaged with the center feed so as to form a housing chamber and a piston chamber within said valve housing.
7. The submersible pumping system of claim 6, wherein a first supply line provides operating fluid at a first pressure to said pump valve and a second supply line provides operating fluid at a second pressure to said pump valve.
8. The submersible pumping system of claim 7, wherein as said piston is moved to the extended position, both the housing chamber and the piston chamber are in fluid communication with the first fluid supply line.
9. The submersible pumping system of claim 7, wherein as said piston is moved to the retracted position, the housing chamber is in fluid communication with the second fluid supply line and the piston chamber is in fluid communication with the first fluid supply line.
10. The submersible pumping system of claim 5, wherein said valve spool further comprises a detent mechanism that releasably couples said valve spool to said valve housing when said pump valve is in the first or second position, wherein said detent mechanism disengages when said upper stop or said lower stop is engaged by said piston.
11. The submersible pumping system of claim 1, wherein the operating fluid has a viscosity of less than 4 centipoise.
12. A submersible pumping system comprising:
a pump housing;
a inlet valve that controls flow of fluid into said pump housing;
an outlet valve that controls the flow of fluid out of said pump housing;
a body coupled to said pump housing;
a piston axially moveable relative to said body between an extended position and a retracted position, wherein in the extended position, said piston projects further into said pump housing;
a pump valve coupled to said body and in fluid communication with a supply of operating fluid, wherein said pump valve has a first position wherein said pump valve supplies operating fluid so as to move said piston to the extended position and a second position wherein said pump valve supplies operating fluid so as to move said piston to the retracted position;
all upper stop coupled to said pump valve, wherein said pump valve is moved to the first position when said upper stop is engaged by said piston in the retracted position; and
a lower stop coupled to said pump valve, wherein said pump valve is moved to the second position when said lower stop is engaged by said piston in the extended position.
13. The submersible pumping system of claim 12 wherein said body is coupled to said pump housing by a flexible coupling.
14. The submersible pumping system of claim 12, further comprising:
a diaphragm coupled to said pump housing so as to separate said pump housing into a working chamber and a pump chamber, wherein said piston is disposed within the working chamber and said inlet and outlet valves control the flow of fluid into and out of the pump chamber.
15. The submersible pumping system of claim 12, wherein said pump valve comprises:
a valve housing coupled to said body; and
a valve spool comprising a center feed that supports said upper stop and said lower stop, wherein the center feed is partially disposed within said piston.
16. The submersible pumping system of claim 15, wherein said piston further comprises a flange that is disposed about the center feed between said upper stop and said lower stop, wherein said flange has an outer edge sealingly engaged with said body and an inner edge sealingly engaged with the center feed so as to form a housing chamber and a piston chamber within said valve housing.
17. The submersible pumping system of claim 16, wherein a first supply line provides operating fluid at a first pressure to said pump valve and a second supply line provides operating fluid at a second pressure to said pump valve.
18. The submersible pumping system of claim 17, wherein as said piston is moved to the extended position, both the housing chamber and the piston chamber are in fluid communication with the first fluid supply line.
19. The submersible pumping system of claim 17, wherein as said piston is moved to the retracted position, the housing chamber is in fluid communication with the second fluid supply line and the piston chamber is in fluid communication with the first fluid supply line.
20. The submersible pumping system of claim 15, wherein said valve spool further comprises a detent mechanism that releasably couples said valve spool to said valve housing when said pump valve is in the first or second position, wherein said detent mechanism disengages when said upper stop or said lower stop is engaged by said piston.
21. The submersible pumping system of claim 12, wherein the operating fluid has a viscosity of less than 4 centipoise.
22. A method for pumping comprising:
disposing a pump assembly into a wellbore, wherein the pump assembly comprises a piston moveable relative to a body;
moving the piston to an extended position by providing a supply of operating fluid to a pump valve in a first position;
shifting the pump valve to a second position by contacting a lower stop with the piston when the piston is in the extended position;
moving the piston to a retracted position by providing a supply of operating fluid to the pump valve in the second position; and
shifting the pump valve to the first position by contacting an upper stop with the piston when the piston is in the retracted position.
23. A The method of claim 22, wherein the pump assembly is disposed within a housing having an inlet valve and an outlet valve, wherein moving the piston to the retracted position draws fluid from the wellbore, through the inlet valve, and into the housing, and wherein moving the piston to the extended position moves fluid out of the housing through the outlet valve.
24. The method of claim 23, wherein a diaphragm separates the pump housing into a working chamber and a pump chamber, wherein the piston is disposed within the working chamber and the inlet and outlet valves control the flow of fluid into and out of the pump chamber.
25. The method of claim 22, wherein operating fluid is released into the wellbore as the piston moves to the retracted position.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1-11. (canceled)
12. A fiber spinning apparatus, comprising:
a polymer supply vessel connected to an inlet side of a spinneret having a polymer flow passage disposed therein, said polymer flow passage exiting said spinneret through at least one spinning nozzle; forwarding gas nozzles having exits disposed adjacent to and directed toward said spinning nozzle, said spinning nozzle extending beyond the exits of said gas nozzles; at least one electrode disposed downstream of said gas nozzles, but outside of a gas flow path established by the direction of the gas flow nozzles; and a fiber collector disposed downstream of said spinning nozzle, wherein each of said spinneret, said electrode and said fiber collector are electrically connected to a circuit containing a high voltage supply, such that each can be individually charged to a potential.
13. The fiber spinning apparatus of claim 12, wherein said polymer supply vessel is a storage tank for a polymer solution.
14. The fiber spinning apparatus of claim 12, wherein said polymer supply vessel is a melt extruder for a polymer melt.
15. The fiber spinning apparatus of claim 12, wherein said gas nozzles are circumferential slots surrounding said spinning nozzle.
16. The fiber spinning apparatus of claim 12, wherein said spinneret is a beam having an angular tip, said polymer flow passage comprises a linear array of capillaries forming said spinning nozzles which exit said spinneret at said angular tip, said forwarding gas nozzles are slots running along the length of said linear array, formed between said angular tip and elongated knife edges disposed on either side of said angular tip, and said electrode comprises two bars running the length of said spinneret.