Mount PD Pumps Correctly

Did you know there’s a “right” way to install a positive displacement (PD) pump? When a pump is installed incorrectly, it potentially leaves a product exposed to biological risk.

In the world of hygienic fluid handling, there are two primary categories of pumps: those that can be cleaned-in-place (CIP) and those that must be taken apart to be cleaned. CIP is a systemic design concern that needs to be considered when installing equipment.

If a pump is designed to be cleaned-in-place, it must be installed appropriately. The proper installation and orientation of a pump are essential to its ability to be cleaned-in-place.

Let’s start by looking at sanitary rotary lobe or circumferential piston pumps (e.g. Alfa Laval SRU, Waukesha U1 or U2, Ampco ZP series). If any of these pumps are positioned with the ports horizontal (parallel to the ground), the casing will not drain. In the case of a Waukesha U1 pump, which must be taken apart to be cleaned, this is not an issue. These pumps can be positioned with their inlets and outlets horizontal because the casing will be drained when the pump is reassembled after cleaning. However, any of these pumps mounted horizontally are not suitable for CIP.

Not drainable PD pump

With the ports mounted horizontally, cleaning solution can’t drain from the bottom of the casing. This pump is not suitable for CIP.

Conversely, SRU, ZP3, or U2 pumps, are intended to be cleaned in place (CIP), but the ports must be positioned vertically (perpendicular to the ground) in order for the casing to drain after CIP. This is true for any of pumps that can be cleaned-in-place.

Drainable PD pump

With the ports mounted vertically, cleaning solution can easily drain from the pump casing, thus making it safe for CIP.

Expert Bio

Michael David, Manager - Service and Repair

Michael David earned his engineering degree at Missouri University of Science and Technology, where the rigorous coursework taught both the theoretical background and the real-world applications of his education. Michael said he enjoys utilizing abstract, technically-minded thinking to arrive at a sensible solution.


Central States Industrial Equipment (CSI) is a leader in distribution of hygienic pipe, valves, fittings, pumps, heat exchangers, and MRO supplies for hygienic industrial processors, with four distribution facilities across the U.S. CSI also provides detail design and execution for hygienic process systems in the food, dairy, beverage, pharmaceutical, biotechnology, and personal care industries. Specializing in process piping, system start-ups, and cleaning systems, CSI leverages technology, intellectual property, and industry expertise to deliver solutions to processing problems. More information can be found at