Pump Warehouse is a master distributor for some of the industry’s most trusted brand name pumps. We also service and fabricate custom pump/motor units.

A crash course in pumps:

This page outlines a few fundamental concepts you should find useful when working with pumps. It covers the main pump types; describes performance characteristics and factors; and provides a quick look at how horsepower requirements are calculated.

Types of Pumps

Engineers describe pumps based on the kind of motion they utilize, displacement, mechanism, cylinders, and pressure.

Reciprocating pumps convert rotary motion to linear motion. Pump speed in rpm determines the pumps output volume for any given combination of cylinder bore and piston stroke.

Positive Displacement pumps are used to move liquids or compress gases. They operate on a ‘what goes in, must come out’ principle.

Reciprocating Positive Displacement pumps may use plungers with static seals; pistons with dynamic seals; or liquid diaphragms to achieve their pumping action. Output may also be a function of the number of cylinders a pump possesses. Commonly, pumps will feature up to six cylinders. Terms like ‘simplex’ (for ‘one’) and ‘triplex’ (for ‘three’) indicate the number of cylinders a particular pump features. A pump increases a fluids pressure when it forces that fluid through a restriction. When the result exceeds 150 psi, its termed ‘high’ pressure.


Performance Characteristics

Crankshaft bearing life, volumetric efficiency, and inlet flow curve are three performance characteristics of practical  significance in many if not most pump applications.

Crankshaft Bearing Life is a function of lubrication, speed, and load. This last factor is calculated as follows:  Plunger Area (in square inches) x Pressure (psi) = Plunger Load (in pounds)


(( Plunger Diameter in inches)2 x p) x Pressure (psi) = Plunger Load (in pounds)

Volumetric Efficiency compares the pumps actual output to its theoretical output. If there were no losses in the pumping system, its flow would equal:

Area x Stroke x Number of Cylinders x Crankshaft Speed
231 in3 /gallon = gpm

Dividing the actual flow by the theoretical value calculated above will yield a value which, taken as a percent, indicates volumetric efficiency. Valve timing is a major factor in achieving good volumetric efficiency. This timing is affected by the relationship among poppet weight, spring rate, poppet travel distance, plunger speed, and plunger diameter.

Inlet Flow Curve relates volumetric efficiency to specific inlet pressures. General Pump provides inlet flow curve charts for all its pumps, on request.


Horsepower Requirements

Because different types of prime movers vary in their pumping performance capabilities, the horsepower required to achieve a given output depends on the energy source.

Hydraulic power is more efficient than either electric power or internal combustion.

Various requirements may be calculated using these relationships:

Hydraulic horsepower required = Pressure x Flow / 1714

Brake horsepower (electric) required = Pressure x Flow / 1457

Gas engine horsepower required = Pressure x Flow / 1100

Please contac Pump Warehouse Company at 800-694-7867 to discuss your pump needs and speak with a process engineer for technical support.

Cat Pumps
General Pump
Giant Pumps
CAT PUMPS: Industrial grade triplex plunger and piston pumps; agriculture, Liquid CO2, misting/fogging, food processing, car wash, pressure washer, and industrial applications GENERAL PUMP: Leader in plunger pumps for the pressure cleaning industry, Vehicle (Car & Truck) Wash, Sewer Jetting, Oil and Gas, Mining, Misting, and industrial applications. GIANT PUMP: High pressure pumps for use in a variety of industrial settings.  Desalination, misting, sewer jetting, car wash, pressure washer, agriculture, food processing, etc.
AR Pumps: Pressure Washing, Cooling, Misting, Sewer Jetting, Reverse Osmosis.
HYPRO Pumps: Pressure Washer, Centrifugal, Diaphragm, Piston, Plunger Pump, Car Wash
GUSHER Pumps: Chemical pumps, ANSI, End Suction, Double Suction, Mag Drive.
Hypro Pumps
Gusher Pumps
MYERS Pumps:  Wastewater Pumps, Grinder, Trash pumps, Sump Pump, Submersible, Non Clog Pumps, Specialty
MEMPHIS Pumps: Centrifugal, End Suction Pumps, Cast Iron, Chemical Sprayer, Condenser, Booster, Bronze, Transfer
UDOR Pumps: Diaphragm, Plunger Pumps, Car Wash, Hydraulic, Reverse Osmosis, De-Icing
F. E. Meyers Pumps
Memphis Pumps
Udor Pumps
WANNER ENGINEERING:  HydraCell Positive Displacement, Non Metallic Centrifugal, Pumps for High Viscosity Liquids, Metering
GOULDS Pumps: Turbine, Vertical, Centrifugal, Wastewater Pumps, Pressure Boost, Wash System, Water Supply
COMET Pumps: Vertical, Axial Pumps, Misting, High Pressure Pumps, Cleaning
Wanner Engineering - Hydra Cell Pumps
Goulds Pumps
Comet Pumps
AMT Pumps: Centrifugal, Dewatering, Submersible, Trash Type, Rotary, Sewer, Industrial Washing
Bell & Gossett Pumps: Compression, Booster, Water Pumps, Submersible, Vacuum Pump, Specialty
Warren Rupp: Air Diaphragm Pump, Metallic Housing, Non Metallic Housing, Chemical Resistant
AMT Industrial Pumps
Bell & Gosset Specialty Pumps
Warren Rupp Pumps


359 New Street, Unit 2   ·  Quakertown, PA 18951

e-mail: [email protected]