Sanitary pumps are used to transport and meter solutions, slurries, and colloids of food and agricultural materials in operations such as food processing that require cleanliness. There are four basic types of sanitary pumps:

• centrifugal
• positive displacement
• jet
• airlift

Centrifugal pumps apply centrifugal force to generate velocity, use rotating impellers to increase velocity, and push fluids through an outlet valve. Positive displacement pumps use rollers, gears, or impellers to move fluid into a fixed cavity so that when liquid exists, the vacuum that is created draws in more fluid. Jet pumps force fluid through a nozzle, converting the fluid’s energy into velocity energy. Airlift pumps mix air or gas with the liquid media so that the air-liquid mixture, with a lower specific weight than the liquid, rises in the pipe and is discharged above the level of the liquid.

Features

Sanitary pumps are available with a variety of features. Adjustable speed pumps can operate at speeds selected by an operator while continuous duty pumps maintain performance specifications at 100% duty cycle. Run dry capable pumps can operate without pumped fluid or external lubrication for an extended period of time. Some wastewater pumps include a backup battery, grinding mechanism, pressure gage, control panel, level control device, thermal overload protection, strainer, filter, or suction. Other wastewater pumps are belt-driven, close coupled, explosion-proof, frame mounted, hygienic, jacketed, sealless, self-priming, portable, or are configured to pump sticky or stringy materials. Multistage, reversible, plug-in, and washdown duty capable devices are also available. Sanitary pumps can move media either vertically or horizontally, depending on the direction of the pump stator/rotor assembly.

 A progressive cavity pump processing soft cheese. Video credit: SEEPEX

Specifications

Important specifications for sanitary pumps include:

• maximum discharge flow
• maximum discharge pressure
• inlet size
• discharge size
• media temperature

Power sources include alternating current (AC), direct current (DC), compressed air, gasoline, diesel fuel, hydraulic systems, natural gas, steam, water, and solar energy. Sanitary pumps that do not include a power source typically provide a drive shaft for connection to a motor. Manually powered pumps rely upon hand or foot power.

Applications

Sanitary pumps are used in a variety of commercial and industrial applications. Examples include agriculture and horticulture, brewery and distillery, dairy, food processing, food service, medical, municipal, OEM supply, and pharmaceutical and biotechnology applications.

Standards

Mandatory sanitation standards vary by product and depend on the regulatory agency that governs processing activities, as well as local or on-site inspectors. Various organizations publish standards. Examples include the Food and Drug Administration (FDA), the United States Department of Agriculture (USDA), and the International Association of Food Industry Suppliers (IAFIS).

Related Information

CR4 Community—Centrifugal Pumps—Torque Speed Curve

Engineering360—Air-Operated Double-Diaphragm Pumps for Food Processing

Engineering360—Positive Displacement Pumps: Operation and Uses

Image credit:

M PUMPS s.r.l. / CC BY-SA 4.0