Peristaltic pumps are a type of positive displacement pump used for pumping a variety of fluids. The fluid is contained within a flexible hose or tube fitted inside the pump casing. The actual pumping principle, called peristalsis, is based on alternating compression and relaxation of the hose or tube, drawing content in and propelling product away from the pump. This process makes a peristaltic pump an accurate dosing pump or metering pump. With an equal amount of liquid dosed each time.
How do peristaltic pumps work?
Peristaltic Pumps use rotating shoes pressed against special flexible tubing or hose to move the fluid through it. The tube is compressed at a number of points in contact with the rollers or shoes. The media is moved through the tube with each rotating motion. The individual components of peristaltic pumps include a pump head, drive, and tubing. Peristaltic pumps are also referred to as flexible member pumps, flexible tube pumps, dispensing pumps, or dosing pumps.
The advantages of peristaltic pumps are that the components of the pump may be chosen when the integrity of the media is a requirement of the application since the fluid type does not contact any internal parts. Seals and valves are not needed as in other pumps.
Many peristaltic pumps come with wash down capabilities and/or IP54 or IP55 ratings. Peristaltic pumps are also reversible and can be flushed to clean out the tubing or hose.
The pump head in peristaltic pumps can have a specified number of rollers. The tubing material and length can often be specified. The tubing in peristaltic pumps is often replaceable or disposable. Some manufacturers will give standard choices of materials for tubing or hose including neoprene, Silicon, and other polymer materials. Silicone rubber is often used in laboratory applications when abrasive and caustic fluids or gases are used. The inner diameter of the tubing is a consideration when working with highly viscous fluids since it will directly affect the flow rate.
When choosing between peristaltic pumps, flow rate is proportional to the rotation of the rollers. This is mainly dependent upon the drive chosen for the peristaltic pump. The drive may be an integral part of the system or can be chosen based upon the flow rate requirements.
Portable peristaltic pumps may be battery operated or hand operated. Other drive options may not necessarily be included with peristaltic pumps including variable speed, heavy duty, and hazardous duty drives.
Peristaltic pumps are used in pharmaceutical, chemical, and food and beverage applications. Based upon the customers requirements, the tubing or hose and pump head configuration can be chosen.