Screw pumps are positive displacement pumps that use at least one screw to transfer fluids. Screw pumps are often used with liquids that contain solid matter, such as sludge, filter cakes and other waste materials. In addition to pumping high viscosity fluids, screw pumps are also used in water and wastewater treatment applications.

Several models of screw pumps are available. Many models are either hydraulic or seal-less. A hydraulic screw pump uses a sealing element for the peripheral edge of the rotatory screw. Screw pumps are used in a wide range of industries, including agriculture, automotive, pharmaceutical, marine and military. Before you buy screw pumps, consider the following:

1. Use rotary screw pumps when pumping low and high viscosity fluids.

2. Order high-pressure screw pumps when the pump will be full submerged in a fluid.

3. Purchase screw vacuum pumps for complex applications.

Action Steps
The best contacts and resources to help you get it done

Order rotary screw pumps

Rotary screw pumps are positive displacement pumps that transfer fluid along an axis. These pumps are ideal when working with high and low viscosity fluids. Rotary screw pumps are commonly used in irrigation and agricultural applications.

I recommend: Order a custom positive displacement rotary screw pump from Warren Pumps. The company manufactures screw pumps to meet your specifications, including low, medium and high pressure. Progressive Pumps offers a broad inventory of pumps, including hydraulic screw pumps and rotary screw pumps. The screw pump distributer frequently serves the agriculture, industrial, marine and sanitary industries.

Implement high-pressure screw pumps

High-pressure screw pumps are designed to be fully immersed in a fluid during operation. It's important to never run a high-pressure pump without liquid. These screw pumps are ideal for transferring filtered lubricating fluids, such as oils and emulsions.

I recommend: Carr Lane Manufacturing offers block and threaded body screw pumps that can either be operated manually with a crank handle or with a power torque wrench. The pumps are capable of reaching 7,500-psi hydraulic pressure. Brinkmann Pumps designs high-pressure screw pumps capable of reaching pressures up to 2,250 psi. These pumps use wear-resistant screw spindles and silicon carbide spindle housings.

Find a vacuum screw pump supplier

A screw vacuum pump is suitable for complex applications, such as the pharmaceutical and chemical industries. These pumps are also ideal for any application that requires a high-vacuum level. Screw vacuum pumps offer oil-free operation and a simple design.

I recommend: Order direct-drive rotary screw vacuum pumps from Q-Air California. The pumps' features include diagnostic gauges, heavy-duty inlet filter, inlet check valve, spin-on fluid filter and air cooled flow. Find several models of vacuum screw pumps at Busch.

Buy a triple or twin screw pump

Screw pumps that use two or three rotating screws are referred to as twin or triple screw pumps. The screws function together, rotating axially clockwise or counterclockwise. The majority of screw pumps use at least two screws.

I recommend: AB Industrial is a manufacturer and distributor of twin and triple screw pumps. The screw pump distributor serves a wide range of industries, including automotive, water treatment and environmental. Find triple screw pumps at Walter A. Wood Supply. The pumps are available with hydraulic balanced screws and various mounting configurations.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Screw pumps that are used in water and wastewater treatment applications require a lower power drive than screw pumps used to transfer liquids with solid materials, such as municipal sludge.