Delivering and metering grease to process valves

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.