FMC M12-HD, Operation & Maintenance Manual, Page: 4 / 20

F M C M 1 2 - H D O P E R A T I O N A N D M A I N T E N A N C E M A N U A L
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General Features
The FMC M12-HD pump is a high performance pump specially designed for the demanding
duties of horizontal drilling. The M12-HD is a piston style pump that utilizes high performance
rubber pistons running in a hardened liner for maximum component life between service. The
pump also features abrasive service valve assemblies with a special seating elements
designed to seal even when sand and other particulates are present in the fluid.
FMC pumps are extremely flexible. They can be powered by engines, electric or hydraulic
motors. FMC supplies many different types of drive connections that allow hydraulic motors
to be directly coupled to the pump frame to save space and weight. Some hydraulic motor
drives incorporate an external gear reduction system. If your pump is equipped with an
external gear reducer, consult the manufacturer for information about operation, service, and
maintenance procedures required for the equipment. FMC M12 pumps do not share common
oil reservoirs with gear reducers.
Standard M12 pump designs require a liner wash system for proper operation. Some
systems are provided directly by FMC, but most are provided by your OEM. Each system is
different, but all incorporate a recirculation tank, circulation pump, and an assortment of
hoses, tubing and nozzles that direct the wash stream to the back of the piston. Once the
wash water has been sprayed on the piston, drain piping collects it and transfers it back to the
supply tank.
The purpose of the liner wash is to provide a small amount of water to the back of the piston
during operation to cool and lubricate the piston. Without this wash water, friction between
the piston and liner generates excessive heat that can cause premature failure of the piston.
Never operate your pump without a clean supply of liner wash water to each of the three
pistons.