Pump and Fluid Systems
Chapter 6: Glossary
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MP-16 2-Piece 5000 psi January 2013
Piston:
A rod which is attached to the crosshead
and is capable of exerting pressure upon the
fluid within the fluid cylinder. The piston
contains its own seals, and moves through a
hardened cavity (see Liner).
Piston Assembly:
The complete piston, including
the cup, hub, rod and seal.
Piston Cup:
The rubber cup on the end of the
piston which transfers its motive power to the
fluid.
Piston Extension:
See Extension Rod.
Piston Hub:
The metal retainer that screws onto
the piston rod and holds the seal and cup in
place.
Piston Hub Seal:
An extended seal directly
behind the piston hub, used to prevent leakage
from the liner.
Piston Rod:
The body of the piston which
connects the hub to the extension rod.
Pitch Line:
The line around the circumference of
a gear along which its teeth are intended to
operate.
Pony Rod:
See Extension Rod.
Power Crosshead:
See Crosshead.
Power End:
The portion of the pump in which the
rotating motion of the crankshaft is converted
into reciprocating motion through the connecting
rods and crossheads. Also known as Gear End.
Power Frame:
The portion of the power end that
contains the crankshaft, connecting rods,
crossheads and bearings used to transmit power
and motion to the fluid end.
Pressure Relief Valve:
See Valve, Pressure
Relief.
Prime Mover:
The device which provides power
to the drive system.
Pulsation Dampener:
A liquid or gas charged,
chambered device that minimizes periodic
increases and decreases in the pressure of a
fluid.
Pump, Charging:
A
pump that provides
pressurized fluid flow to the suction of the main
pump.
Pump, External Lubricating:
An electrically
powered pump located outside of the power
frame which provides lubrication pressure to the
pump crankcase.
Pump, Internal Lubricating:
A crankshaft-
powered pump located inside of the crankcase
which provides it with lubrication pressure.
Pump, Liner Wash:
An electric centrifugal pump
circulating liner wash and cooling fluid from the
liner wash tank to the liner spray nozzles.
Pump, Triplex:
A reciprocating pump utilizing
three plungers or pistons working in three
separate cylinders, designed so that its power
strokes are evenly distributed over the course of
a crankshaft revolution.
Race:
A groove in a machine through which a
moving part slides or rolls.
Retainer:
A device which affixes one component
to another, usually mounting a component onto
a frame.
Rod Clamp:
The clamp which affixes the piston
or plunger rod to the extension rod.
Seal:
A device designed to prevent fluids from
leaving a specific location.
Seat Driver:
A driving tool used to move the seat
into position in the cylinder, consisting primarily
of a long, heavy rod with a seat adapter at the
end.
Seat Puller:
A system used to remove the valve
seat from the cylinder. The system comes in
many configurations, but most commonly
consists of a valve seat adapter attached to a
pulling rod, which itself is mounted on a heavy
duty frame and driven by a manual hydraulic
pump. The when the pump is used, the pulling
rod exerts vertical pressure on the seat,
eventually wrenching it free from the fluid
cylinder.
Service Crane:
See Jib Crane.
Settling Tank:
A tank designed to filter solid
contaminants from fluid by allowing them to
settle in the base of the tank while the fluid flows
over.
Shield:
A type of guard designed to protect
against flying debris or components.
