Cooling Tower Sump Tanks

When a separate indoor cooling tower sump tank is needed to maintain an adequate water supply for the cooling tower, Midwest Tank Co. has a variety of options available. Every job site has a unique space available for equipment. Midwest Tank Co. makes it easy to specify our tank as we build it specifically for each job. We have produced cooling tower sump tanks that are rectangular, round, and bolt together styles to be assembled in the field. Whether you want a lined cooling tower sump tank or a stainless tank, Midwest Tank Co. has built it. We will provide a model number with a drawing to match your specific need. Specify Midwest Tank Co. as your experienced tank builder.

Many cooling tower manufacturers recommend a separate indoor sump tank large enough to fill the entire recirculation system without danger of pump cavitations. As a general rule, the tank should be sized to hold three times the rate of circulation in gallons per minute (gpm). Every tank should have properly sized openings to include: an inlet, outlet, overflow, drain, manhole, water make up, vent and misc. fittings. It is extremely important that the tank is vented properly and does not carry a water column in the vent pipe causing an additional static head pressure on the vessel. If additional head pressure is a possibility, the additional head pressure should be calculated and built into the design of the tank.

The majority of our cooling tower sump tanks are sandblasted interior to a near white, followed by 7 to 11 mils DFT of epoxy. If the tank has a flat bottom, the exterior bottom of the tank should have a commercial blast followed by a coal tar epoxy, to protect from the condensation. The alternative is that the bottom is supported on a structural skid to get the tank off the floor. Midwest Tank Co. recommends the side wall and top to have a commercial blast followed by a universal primer as a minimum. Finish coating is available.

Options inside the vessel include: an anti-vortex on the suction side, interior baffle, and internal screen.

Note: Rectangular tanks made of steel and epoxy lined require structural support on the outside of the tank. Lined tanks require all welds to be continuous, therefore; interior structural support becomes costly. Stainless steel rectangular tanks may have the structural support on the inside of the tank with staggered fillet welds.

Round cooling tower sump tank options available.

Custom Cooling Tower Sump Tanks for Reliable Water Management

Midwest Tank Company designs and fabricates cooling tower sump tanks tailored to your job site’s space and system requirements. Whether you need a rectangular or round, we build each vessel to spec, offering lined and stainless steel options with detailed drawings for approval. Our tanks are built to maintain adequate water supply, prevent pump cavitation, and support long-term system performance.

Why Use a Separate Indoor Sump Tank?

Cooling tower manufacturers often recommend a dedicated sump tank to stabilize water levels and prevent pump damage. A properly sized tank, typically three times the system’s circulation rate in GPM, ensures consistent flow and protects against cavitation. MWT includes all necessary fittings: inlet, outlet, overflow, drain, manhole, makeup water, vent, and more. We also account for static head pressure in vent design to avoid system strain.

Construction and Coating Options

Our sump tanks are built for durability and corrosion resistance. Interiors are sandblasted to near white and coated with 7–11 mils DFT of epoxy. Flat-bottom tanks receive coal tar epoxy on the underside or are mounted on structural skids to prevent condensation damage. Sidewalls and tops are commercially blasted and primed, with optional finish coatings available. Internal features include anti-vortex fittings, baffles, and more.

FAQs

What Does a Cooling Tower Sump Tank Do?

It stores and regulates water for the cooling tower system, preventing pump cavitation and ensuring consistent circulation.

How Do I Size a Sump Tank Correctly?

A common guideline is to size the tank to hold three times the system’s circulation rate in gallons per minute (GPM).

Can You Build Tanks for Tight or Irregular Spaces?

Yes. We offer custom rectangular and round designed to fit your available footprint and assembly needs.

What Coatings are Available for Corrosion Protection?

We offer epoxy-lined interiors, coal tar epoxy for flat bottoms, and universal primers for exterior surfaces. Finish coatings are also available upon request.