Metering pump

A metering pump comprising:

• a head having an internal chamber interconnecting a pump port, an inlet valve port and an outlet valve port of said head;
• a pump cylinder, an inlet valve and an outlet valve removably mounted in said pump port, said inlet valve port and said outlet valve port respectively;
• said inlet and outlet valves each include a first body member having a first flange adjacent to a first end, and a second body member having a first end receiving said first end of said first body member and a first face of said first flange;
• said second body member having a second flange with a first face adjacent to a shoulder of said valve port;
• and
• said mounting means adjacent to a second face of said first and second flanges for securing said first and second flanges to a respective port.

A metering pump comprising:

• a head having an internal chamber interconnecting a pump port, an inlet valve port and an outlet valve port of said head;
• a cylinder mounted to and closed at a first end by said head at said pump port;
• a piston movable in said cylinder;
• said piston including a piston rod and a piston head removably mounted to first end of said piston rod;
• a bushing mounted to said piston rod adjacent to said first end of said piston rod;
• and
• said piston head forming a stop for one end of said bushing and a break-away stop connected to said piston rod forming a stop for a second end of said bushing.

A metering pump comprising:

• a head having an internal chamber interconnecting a pump port, an inlet valve port and an outlet valve port of said head;
• a pump cylinder, an inlet valve and an outlet valve removably mounted in said pump port, said inlet valve port and said outlet valve port respectively;
• and
• a bore in said head adjacent to said outlet port for receiving a suck-back adjustment device to interact with said outlet valve to adjust the degree of closure of the outlet valve and for receiving a plug threadably received in said bore when no suck-back device is present.

A metering pump comprising:

• a head having an internal chamber interconnecting a pump port, an inlet valve port and an outlet valve port of said head;
• a pump cylinder, an inlet valve and an outlet valve removably mounted in said pump port, said inlet valve port and said outlet valve port respectively;
• said inlet and outlet valves each including an identical first body member having a first valve seat adjacent to its first end, and an identical second body member having a second valve seat adjacent to its first end;
• said first and second body members mating at their second ends and said first end of said first body member being in said valve port;
• and
• said inlet and outlet valves each including an identical check valve structure which is positioned in said inlet valve body members to seal on said second valve seat and is positioned in said outlet valve body members to seal on said first valve seat.

A suck-back valve comprising:

• a body having an internal chamber interconnecting an inlet valve port and an outlet valve port of said valve;
• a valve seat in said body between said ports;
• a valve member in said internal chamber;
• and
• a stem extending from the exterior of said body into the interior of said body and including an eccentric cam which is extendable through one of said ports and past said valve set to interact with said valve member to adjust the degree of closure of the valve by rotating said stem.

A metering pump comprising:

• a head having an internal chamber interconnecting a pump port, an inlet valve port and an outlet valve port of said head;
• a pump cylinder, an inlet valve and an outlet valve removably mounted in said pump port, said inlet valve port and said outlet valve port respectively;
• said inlet and outlet valves being from a group consisting of check valves, duck bill valves and spool valves;
• said valve ports have a single design to accept all of said valves;
• and
• means independent of said valves for securing any of said valves to said valve ports.

A metering pump comprising:

• a head having an internal chamber interconnecting a pump port, an inlet valve port and an outlet valve port of said head;
• a pump cylinder, an inlet valve and an outlet valve in said pump port, said inlet valve port and said outlet valve port respectively;
• and
• mounting means independent of said cylinder, inlet valve and outlet valve for removably mounting said pump cylinder, said inlet valve and said outlet valve in said pump port, said inlet valve port and said outlet valve port respectively and operable by hand without tools.