What Happens When You Submerge an AODD Pump?

How to Submerge an AODD Pump the Right Way

If the application truly requires submersion, the right approach is not to improvise and hope. It is to make sure the pump is configured for it.

• Route the exhaust above the liquid level. In practice, this is often described as using a snorkel, hose or pipe on the exhaust so the pump can vent to open air.

• Use the correct submersible exhaust configuration. Some pumps use a single-point exhaust or a check-valve style exhaust setup to prevent backflow.

• Keep the exhaust path clear. A submerged setup that exhausts through a clogged muffler, blocked passage or paint-filled outlet will still fail.

• Protect the inlet. If the pump is sitting in a pit or dirty liquid, use a strainer or screened base so sticks, trash and solids do not exceed the pump's solids handling limit.

Wilden® highlights this directly in several product resources. Its utility application pumps are described as portable and available in a single-point exhaust option for submersible applications. The Stallion® series brochure also references a check-valve exhaust for submersion on certain models (PDF source).

Not Every AODD Pump Is Automatically Submersible

This is the most important correction for buyers and maintenance teams: not every AODD pump should be treated as a drop-in submersible pump. Some models can be configured for submerged service. Others should not be submerged in standard form.

That is why it is risky to assume all air-operated pumps can be thrown into a pit the same way. The right answer depends on the air distribution system, the exhaust arrangement, and the specific product family.

For example, PSG's® current resources note submersible capability for certain Pro-Flo® SHIFT and Turbo-Flo™ configurations, while Accu-Flo™ support resources and other model-specific documents should be reviewed before assuming the same setup applies there.

What Submersion Does to Pump Life

Submersion by itself does not automatically destroy an AODD pump. In many utility and sump applications, the bigger life issue is the environment around the pump, not the water touching the outer body.

Dirty pits and flooded work areas usually contain grit, stringy debris, stones, trash and other solids that can damage check balls, seats, diaphragms and strainers. That means the long-term wear driver is often debris ingestion, not the fact that the pump body was underwater.

In other words, a properly configured submerged AODD pump may run fine, but it still needs the same things every AODD pump needs: clean air, a clear exhaust path and protection from solids that exceed its design limits.

The Maintenance Mistake That Causes "It Still Does Not Run"

One of the most common post-rebuild mistakes in AODD service is cleaning the obvious liquid mess but forgetting the small air passages and mufflers. If a diaphragm failure sprayed paint, sludge or other product into the air side, the pump can be rebuilt and still run badly because the mufflers or exhaust passages remain blocked.

This matters even more in submerged service because the pump already depends on an unrestricted exhaust path. If the front passage, muffler or routed exhaust line is packed with residue, the pump may look repaired but still fail to breathe.

If you need replacement diaphragms or repair parts after a wet-end failure, start with genuine parts and repair kits.

Common Mistakes When Submerging an AODD Pump

• Dropping a standard pump underwater without confirming it has a submersible-capable exhaust configuration.

• Leaving the muffler or exhaust outlet underwater with no hose or snorkel above the fluid level.

• Ignoring secondary exhaust passages or pilot exhaust details on models that require a specific gasket or routing change.

• Using the pump in dirty pits with no inlet protection, then blaming the pump when debris jams the check valves.

• Assuming any non-electric pump can be submerged the same way, even though other pump types may still have bearings, weep holes or drive systems that are not meant to go underwater.

A Simple Rule of Thumb

If the job requires true underwater operation, do not ask only, "Can an AODD pump be submerged?" Ask, "Is this exact pump configured for submerged service, and is the exhaust routed correctly?" That is the question that actually determines whether the setup will work.

AODD pumps can be a strong answer for utility pits, sump work and temporary flooded conditions - but only when the air side is protected and the exhaust can vent above the liquid.

Next Steps: Confirm the Right Configuration

If you are trying to choose a pump for sump or submerged duty, start with the Pump Finder or contact the PSG® Store team to confirm whether the model and exhaust setup are right for your application.

You can also browse AODD options by brand: Shop Wilden® and Shop All-Flo®.