In a chemical feed system, which of the following pumps is most likely to be used?

• A. End suction centrifugal
• B. Split case
• C. Rotary
• D. Peristaltic

Answer: (D)

For chemical feed, you need a pump that provides precise, controllable dosing while keeping the chemical isolated from the pump mechanism to prevent leaks and contamination. A peristaltic pump fits this need because the fluid only contacts the interior of a flexible tubing, so you can choose tubing materials that are fully compatible with the chemical and avoid seals that could corrode or leak. The pumping action is positive displacement, delivering a known volume with each rotation, so adjusting the flow is straightforward by changing the pump speed or tube size, which makes accurate metering reliable even as back pressure varies in the feed line. Tubing is the only wear part, so maintenance is simple and fast—replacement reduces downtime and cross-contamination between chemicals. The design also handles a range of viscosities and small, precise flows well, which is ideal for dosing.

End suction centrifugal pumps are better for larger, less viscous flows and their output varies with system pressure, making precise dosing harder. Split-case pumps are intended for high-flow, high-head service and are not geared toward metering small, precise quantities. Rotary pumps can meter, but they involve mechanical seals and components that can complicate maintenance in aggressive chemical environments, making peristaltic pumps the more straightforward, robust choice for dosing.