Positive Displacement Pumps & Pump Suppliers
What are Positive Displacement Pumps?
Positive displacement pumps, also known as P.D. pumps, are a broad category of pumps, second only to centrifugal pumps in terms of their popularity. Generally speaking, positive displacement pumps are used for special applications such as viscous liquids or liquids containing fragile solids. Compared to centrifugal pumps they are not capable of as high of flow rate, but are able to produce much higher pressures.
Positive displacement pumps move a liquid and pressurize it to allow it to pass through the system by drawing the liquid into a chamber, then contracting the chamber to force the liquid out of the pump at the necessary pressure to move through the piping system.
Positive displacement pumps do not have impellers, but rather rely on rotating or reciprocating parts to directly push the liquid in an enclosed movable volume, until enough pressure is built up to move the liquid into the discharge system. Because positive displacement pumps don’t rely on raising the velocity of the fluid as the centrifugal pump does by moving the liquid through the impeller, the fluid velocity inside a positive displacement pump is much lower than a centrifugal pump, which is often a desirable feature for certain applications such as pumping fragile solids.
Positive displacement pumps generally work within the following ranges:
- Flow rate ranges between .1 and 15,000 gpm
- Total head (pressure) ranges between 10 and 100,000 psi
- Horsepower ranges between 0.5 and 5,000 hp
- Viscosity limits vary with pump type, but some positive displacement pumps can handle millions of SSU viscosity
Types of Positive Displacement Pumps
There are two main types of positive displacement pumps:
1. Rotary pumps - including gear pumps, screw pumps, vane pumps, peristaltic pumps, lobe pumps, and progressive cavity pumps — use rotating parts to move the liquid in and out of the pump chamber. Some rotary pumps, such as gear pumps, must have very tight clearance between the rotating elements and the walls of the chamber, and between the rotating parts, which means they generally can’t be used to pump large solids or abrasive fluids that may wear the parts. Other types such as lobe pumps and progressive cavity pumps are designed to move liquids containing solids.
2. Reciprocating pumps - including plunger pumps, diaphragm pumps, piston pumps, hydraulic pumps, and many others - use a repetitive reciprocating mechanism to expand and contract the chamber at regular intervals. Reciprocating positive displacement pumps incorporate one or more sets of check valves at the inlet and outlet of the pump to help guild the liquid through the pump and to prevent reverse flow.
Advantages of Positive Displacement Pumps
In general, positive displacement pumps are ideal for applications where a constant flow is needed. Note that many types of positive displacement pumps require pressure protection via a relief valve to safeguard the pump and system from over pressurization. They create medium to high pressure, and are often an excellent way to pump oils and other viscous fluids. Positive displacement pumps may also be needed for low flow and high pressure combination, to pump fluids containing fragile solids, or for other application niches. Some types are inherently self-priming, and several types are seal less.
Here are some positive displacement pump manufacturers to consider.
Action Pump sells several positive displacement pumps including drum pumps, siphon pumps, piston pumps, double diaphragm pumps, rotary pumps, hand pumps and much more. Most of the PD pumps that Action Pumps produces are used to transfer pumps from drums or barrels.
Anchor Sales distributes centrifugal pumps and PD pumps for the industrial, process, water treatment, fire protection, utility markets and more. Anchor Sales offers 26 different pump types including: AODD Pumps, Diaphragm Pumps, Gear Pumps, Lobe Pumps, Metering Pumps, Peristaltic/Hose Pumps, Vane Pumps.
Arizona Pump & Equipment is a distributor of pumps, motors, drives, controls, and more throughout the state of Arizona. Arizona Pump & Equipment offers 37 different pump types including: AODD Pumps, Concrete Pumps, Diaphragm Pumps, Flexible Impeller Pumps, Gear Pumps, Lobe Pumps, Metering Pumps.
Chemac, Inc. offers several positive displacement pump types including metering pumps, diaphragm pumps, piston pumps, gear pumps, plunger pumps and much more. The company makes PD pumps for process applications where dangerous fluids are involved.
Gorman-Rupp is a leading manufacturer of centrifugal pumps and lift and booster systems. Gorman-Rupp Company offers 8 different pump types including: Diaphragm Pumps, Gear Pumps, Booster Pumps, Self-Priming Pumps, Submersible Pumps, Fire Pumps, Drum Pumps.
Haight Pump is a manufacturer of centrifugal pumps and positive displacement pumps for the OEM and process market. Haight Pump offers 3 different pump types including: Gear Pumps, End Suction Pumps, Self-Priming Pumps.
Hoffman-Kane Distributors, Inc. distributors pumps and pump parts, seals, gaskets and more. The company is located in Bethel Park, PA. Hoffman-Kane Distributors, Inc. offers 11 different pump types including: AODD Pumps, Gear Pumps, API Pumps, End Suction Pumps, Horizontal Split Case Pumps, Self-Priming Pumps, Circulator Pumps.
JGB Enterprises makes pumps, industrial and hydraulic hoses and accessories for the automotive, marine, construction, chemical and other applications. JGB Enterprises offers 4 different pump types including: Plunger Pumps, Drum Pumps, Fire Pumps, API Pumps.
KD Scientific manufacturers equipment for use in the laboratory environment. KD Scientific offers 1 different pump types including: Metering Pumps.
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Laborde Products distributes diesel powered equipment and engines for the industrial and marine industries. Laborde Products offers 10 different pump types including: Diaphragm Pumps, Gear Pumps, Piston Pumps, Plunger Pumps, Slurry Pumps, Well Pumps, Vertical Sump Pumps.
Lobee Pump & Machinery makes pumps for the chemical, agriculture, construction applications and more. Lobee Pump & Machinery offers 2 different pump types including: Gear Pumps, Vertical Sump Pumps.
Mechanical Equipment Company (MECO) sells and services skid mounted pump systems for the fire protection, commercial, industrial markets and more. Mechanical Equipment Company (MECO) offers 36 different pump types including: AODD Pumps, Diaphragm Pumps, Flexible Impeller Pumps, Gear Pumps, Lobe Pumps, Metering Pumps, Peristaltic/Hose Pumps.
River City Pump sells pumps to the water and waste water market. River City Pump & Supply offers 18 different pump types including: Metering Pumps, Peristaltic/Hose Pumps, Progressive Cavity Pumps, Well Pumps, End Suction Pumps, Regenerative Turbine Pumps, Jet Pumps.
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Industry Updates
Griswold Pump's 811 Series ANSI Centrifugal Pumps is ideal for use in coke-manufacturing processes.
ITT Corporation completed its acquisition of Blakers Pump Engineers, a long-time distributor of ITT's Goulds Pumps in Australia. Goulds makes industrial pumps for the chemical, oil and gas, mining, and power markets.
Agilent Technologies Inc.has acquired P.V.R. s.r.l., a long-established vacuum pump manufacturer based in Valmadrera, Italy.
Pump Tweets
A Water Pumps Direct states in a company press release that it will now sell Bur-Cam water pumps. The company’s website, WaterPumpsDirect.com also sells sprinkler pumps, well pumps, jet pumps, submersible pumps and more.
ITT Corp completes its acquisition of Blakers Pump Engineers. Blakers Pump Engineers is a long-time distributor of the Goulds Pumps brand in Australia. The company sells horizontal and vertical centrifugal pumps for the oil & gas, mining, water treatment, refining and other markets.
ITT Goulds Pumps announced a worldwide effort to celebrate pumps. The company has established a Pump Appreciation Day on April 10, 2012. A company press release states that various festivities will recognize people who keep pumps running.