Grease system for high pressure plug valves

1. A method of distributing high viscosity grease to at least one plug valve, comprising:

loading a detachable cartridge by loading a first space within the cartridge with solid grease, the first space defined by a first wall of a piston movable within the cartridge and a first end wall of the cartridge;

attaching the detachable cartridge to a manifold having a manifold chamber and a plurality of valves in fluid communication with the manifold chamber;

introducing a fluid under pressure into a second space within the cartridge, the second space defined by a second opposing wall of the piston and a second end wall of the cartridge, to drive the piston and compress the solid grease within the first space of the cartridge and produce flowing grease;

transmitting the flowing grease from the first space of the cartridge to the manifold chamber; and

selectively opening each of the plurality of valves for distributing the flowing grease to corresponding grease ports of the at least one plug valve.

2. The method of claim 1 , wherein loading the detachable cartridge comprises loading a plurality of detachable cartridges and the method further comprises selecting one of the plurality of loaded detachable cartridges for attaching to the manifold.

3. The method of claim 2 , further comprising:

determining that a detachable cartridge attached to the manifold has insufficient remaining grease within the first space of the cartridge;

detaching the detachable cartridge attached to the manifold; and

attaching one of the plurality of loaded detachable cartridges to the manifold.

4. The method of claim 1 , wherein loading a detachable cartridge by loading a first space within the cartridge comprises loading the first space of the detachable cartridge with solid grease having a National Lubricating Grease Institute (NLGI) consistency number of at least 3.

5. The method of claim 1 , wherein attaching the detachable cartridge to a manifold comprises attaching the detachable cartridge to the manifold with a hammer union coupling.

6. The method of claim 1 , wherein introducing a fluid under pressure into a second space within the cartridge comprises introducing water under pressure into the second space within the cartridge.

7. The method of claim 6 , wherein introducing water under pressure into the second space within the cartridge comprises:

storing, in a vessel, a volume of water approximating a volume of solid grease in the first space of the cartridge;

pumping water from the vessel to the second space of the cartridge; and

approximating from the water remaining in the vessel an amount of grease that has flowed from the first space of the cartridge to the manifold chamber.

8. The method of claim 1 , wherein selectively opening the plurality of valves comprises selectively opening each of the plurality of valves by air pressure actuation.

9. The method of claim 1 , further comprising reducing pressure within the manifold chamber by actuating a valve in fluid communication with the manifold chamber.

10. A method of distributing high viscosity grease to at least one plug valve, comprising:

loading a cartridge by loading a first space within the cartridge with solid grease, the first space defined by a first wall of a piston movable within the cartridge and a first end wall of the cartridge;

attaching the cartridge to a manifold having a manifold chamber and a plurality of valves in fluid communication with the manifold chamber;

introducing a fluid under constant pressure into a second space within the cartridge, the second space defined by a second opposing wall of the piston and a second end wall of the cartridge, to drive the piston and compress the solid grease within the first space of the cartridge and produce flowing grease;

transmitting the flowing grease from the first space of the cartridge to the manifold chamber; and

wherein all of the plurality of valves are open for distributing the flowing grease to corresponding grease ports of the at least one plug valve.

11. A system for distributing high viscosity grease to at least one plug valve, comprising:

a detachable cartridge comprising:

a body defining a chamber;

a piston disposed within the chamber and defining a first space adapted to receive solid grease and a second opposing space for receiving fluid for driving the piston to compress the solid grease received within the first space;

an outlet in fluid communication with the first space for providing flowing grease from the first space under compression from the piston; and

an inlet in fluid communication with the second space for introducing fluid into the second opposing space for driving the piston; and

a manifold for detachable coupling to the detachable cartridge and having a manifold chamber for receiving flowing grease from the outlet of the cartridge and a plurality of valves in fluid communication with the manifold chamber for selectively distributing grease from the manifold chamber to conduits for selective coupling to corresponding grease ports of the at least one plug valve.

12. The system of claim 11 , wherein the manifold detachably couples to the cartridge with a hammer union coupling.

13. The system of claim 11 , wherein the body of the cartridge comprises a cylinder.

14. The system of claim 11 , wherein the first space of the chamber of the body is adapted to receive solid grease having a National Lubricating Grease Institute (NLGI) consistency number of at least 3.

15. The system of claim 11 , wherein the fluid comprises water and the system further comprises a water system coupled by a conduit to the inlet for providing the water under pressure to the second opposing space of the chamber.

16. The system of claim 15 , wherein the water system comprises:

a vessel for holding a volume of water approximating a volume of solid grease in the first space of the chamber of the body of the cartridge; and

a pump for a pumping water from the vessel to the second opposing space of the body of the cartridge, an amount of water pumped from the vessel approximating an amount of grease flowing from the first space of the body of the cartridge to the manifold chamber.

17. The system of claim 16 , further comprising a mechanism for monitoring the amount of water pumped from the vessel.

18. The system of claim 11 , wherein each of the plurality of valves is associated with a corresponding actuator for controlling operation of the valve.

19. The system of claim 18 , wherein the actuator opens a corresponding valve in response to air pressure and the system further comprises a source of air pressure for controlling each of the plurality of valves.

20. The system of claim 19 , wherein each of the plurality of valves closes in response to spring action.

21. The system of claim 11 , wherein the manifold chamber comprises a port and the system further comprises a valve in fluid communication with the port for selectively reducing pressure from the manifold chamber.