Water pumps move water that does not contain suspended solids or particulates. These pumps are not so much a type of pump as they are a classification based on the media being transferred. Nearly every pump type that is defined by either a complementary application (fountain water pumps, submersible water pumps) or by motive type (such as centrifugal, cantilever, or hand water pumps) can be used in water service applications. See the main pumps page for links to pumps classified by motive force.

Types of Water Pumps

While slurries and the like are best handled by wastewater or sewage pumps, water pumps can handle clear water such as these types:

Condensate pumps transport or collect and transport condensate collected from a steam system back into the system for reheating and reuse. These pumps close the boiler-steam-condensate loop by returning hot condensate back to the system. This takes advantage of valuable BTUs, which would otherwise go to waste. Condensate pumps can also be used for the removal of unwanted condensate from an HVAC or appliance collection pan.

Ground water pumps pump untreated water that is found on or collects freely on the ground.  

Potable water pump move water that is considered safe and fit for human consumption, culinary and domestic purposes and meets the requirements of the health authority having jurisdiction.

Salt water pumps pump water that has a high concentration of salt, often from the ocean.

Specifications

When selecting a water pump, flow discharge pressure, material of construction, and power source are key criteria to understand. In order to evaluate flow output, it is critical to consider the pressure or head that the pump is working against. Always consult the manufacturer's pump curve to determine the actual flow at any given pressure. All pumps have a maximum pressure that they can pump against, and the pump’s flow output diminishes as the pressure they are pumping against increases.

Maximum discharge flow: The maximum flow the pump is designed to generate. This value is dependent on the system or pressure head the pump must enter.          

Maximum discharge pressure: The maximum pressure the pump is capable of generating while staying within design restraints.  

Power Source

There are a variety of power sources that are used to operate water pumps. Power source comes down to availability, safety, and in many cases, portability. If the pump is not supplied with a power source the pump mechanism is the only power source. Typically, a drive shaft for connection of motor or other power source is provided.

• AC voltage
• DC voltage
• Compressed or pneumatic air source
• Gasoline or diesel engine
• Hydraulic system
• Manual
• Natural gas
• Solar powered
• Steam
• Water

Material

Material of construction is another key factor to consider when selecting a water pump. Care should be taken to choose a material that is best suited for the media and application in which the pump is to operate.

Aluminum is a bluish silver-white malleable ductile light trivalent metallic element that has good electrical and thermal conductivity, high reflectivity, and resistance to oxidation.

Brass or bronzes comes with good strength, excellent high temperature ductility and reasonable cold ductility, good conductivity, excellent corrosion resistance, good bearing properties and low magnetic permeability. Sintered bronze is a porous material, which can be impregnated with oil, graphite or PTFE. Not suitable for heavily loaded applications but useful where lubrication is inconvenient.        

Cast iron refers not to a single material, but to a family of materials whose major constituent is iron, with important trace amounts of carbon and silicon. Cast irons are natural composite materials whose properties are determined by their microstructures - the stable and metastable phases formed during solidification or subsequent heat treatment.    

Plastics are any of various organic compounds produced by polymerization, capable of being molded, extruded, cast into various shapes and films, or drawn into filaments used as textile fibers.          

Stainless steel is chemical and corrosion resistant and can have relatively high pressure ratings. 

Standards

The Hydraulic Institute develops comprehensive, ANSI-approved pump standards; an example standard is HI M100: Complete Set of ANSI/HI Pump Standards.

Image credits:

Pentair |  GRI Pumps