Delivering and metering grease to process valves

1. A system, comprising:

first and second lubricator valves, actuable to:

a first configuration in which the first lubricator valve is open and the second lubricator valve is closed; and

a second configuration in which the first lubricator valve is closed and the second lubricator valve is open;

a grease cylinder including:

an inlet via which grease is deliverable into the grease cylinder; and

an outlet via which grease is communicable to the first and second lubricator valves;

an inlet valve operably associated with the inlet and adapted to communicate grease to the inlet and to prevent, or at least reduce, backflow of grease out of the inlet through the inlet valve;

a piston extending at least partially within the grease cylinder; and

an actuator operably associated with the piston and adapted to stroke the piston:

back within the grease cylinder to deliver grease, via the inlet valve and the inlet, into the grease cylinder; and

forth within the grease cylinder to deliver grease, via the outlet, out of the grease cylinder and to:

a first process valve via the first lubricator valve when the first and second lubricator valves are in the first configuration; and

a second process valve via the second lubricator valve when the first and second lubricator valves are in the second configuration.

2. The system of claim 1 , wherein the actuator comprises a power cylinder within which the piston at least partially extends, the piston comprising a head portion slidably disposed in the power cylinder and dividing the power cylinder into first and second chambers.

3. The system of claim 2 , wherein the head portion has a first cross-sectional area, and the piston further includes another portion contacting the grease in the grease cylinder and having a second cross-sectional area, the second cross-sectional area being less than the first cross-sectional area.

4. The system of claim 3 , further comprising:

a control valve operably associated with the power cylinder;

wherein the control valve:

strokes the piston back within the grease cylinder by communicating power fluid to the first chamber and, at the same time, communicating power fluid from the second chamber; and

strokes the piston forth within the grease cylinder by communicating power fluid to the second chamber and, at the same time communicating power fluid from the first chamber.

5. The system of claim 1 , further comprising:

the first process valve;

wherein the first lubricator valve is operably associated with the first process valve.

6. The system of claim 1 , further comprising:

the first and second process valves;

wherein the first lubricator valve is operably associated with the first process valve; and

wherein the second lubricator valve is operably associated with the second process valve.

7. The system of claim 1 , further comprising:

an outlet valve operably associated with the outlet and adapted to communicate grease from the outlet and to prevent, or at least reduce, backflow of grease through the outlet valve and into the outlet.

8. The system of claim 6 , wherein the inlet valve is or includes a first check valve, and the outlet valve is or includes a second check valve.

9. The system of claim 1 , further comprising a cycle counter that counts the strokes of the piston.

10. The system of claim 9 ,

wherein the actuator is further adapted to:

start stroking the piston; and

stop stroking the piston; and

wherein the system further comprises a control unit adapted to:

receive data/signal(s) relating to the strokes counted by the cycle counter; and

cause the actuator to stop stroking the piston when the strokes counted by the cycle counter equal a predetermined number of strokes.

11. A method, comprising:

stroking a piston back within a grease cylinder using an actuator operably associated with the piston, wherein:

the piston extends at least partially within the grease cylinder;

the grease cylinder includes:

an inlet via which grease is deliverable into the grease cylinder; and

an outlet via which grease is communicable to first and second lubricator valves;

the first and second lubricator valves are actuable to:

a first configuration in which the first lubricator valve is open and the second lubricator valve is closed; and

a second configuration in which the first lubricator valve is closed and the second lubricator valve is open;

an inlet valve is operably associated with the inlet, and is adapted to communicate grease to the inlet and to prevent, or at least reduce, backflow of grease out of the inlet through the inlet valve; and

stroking the piston back within the grease cylinder delivers grease, via the inlet valve and the inlet, into the grease cylinder;

stroking the piston forth within the grease cylinder, using the actuator, to deliver grease, via the outlet, out of the grease cylinder and to:

a first process valve via the first lubricator valve when the first and second lubricator valves are in the first configuration; and

a second process valve via the second lubricator valve when the first and second lubricator valves are in the second configuration.

12. The method of claim 11 , wherein the actuator comprises a power cylinder within which the piston at least partially extends, the piston comprising a head portion slidably disposed in the power cylinder and dividing the power cylinder into first and second chambers.

13. The method of claim 12 , wherein the head portion has a first cross-sectional area, and the piston further includes another portion contacting the grease in the grease cylinder and having a second cross-sectional area, the second cross-sectional area being less than the first cross-sectional area.

14. The method of claim 13 ,

wherein a control valve is operably associated with the power cylinder; and

wherein the control valve:

strokes the piston back within the grease cylinder by communicating power fluid to the first chamber and, at the same time, communicating power fluid from the second chamber; and

strokes the piston forth within the grease cylinder by communicating power fluid to the second chamber and, at the same time communicating power fluid from the first chamber.

15. The method of claim 11 , wherein:

the first lubricator valve is operably associated with the first process valve.

16. The method of claim 15 , wherein:

the second lubricator valve is operably associated with the second process valve.

17. The method of claim 11 , wherein:

an outlet valve is operably associated with the outlet and adapted to communicate grease from the outlet and to prevent, or at least reduce, backflow of grease through the outlet valve and into the outlet.

18. The method of claim 17 , wherein the inlet valve is or includes a first check valve, and the outlet valve is or includes a second check valve.

19. The system of claim 11 , further comprising:

counting the strokes of the piston using a cycle counter.

20. The method of claim 19 , wherein:

the actuator is further adapted to:

start stroking the piston; and

stop stroking the piston; and

wherein the method further comprises:

receiving, using a control unit, data/signal(s) relating to the strokes counted by the cycle counter; and

causing, using the control unit, the actuator to stop stroking the piston when the strokes counted by the cycle counter equal a predetermined number of strokes.