What is a Dump Valve?

Mary McMahon
Mary McMahon

A dump valve is a valve that allows for the rapid release of material. Such valves can be fitted for safety in emergencies and for other reasons on a wide variety of devices, from tanker trucks to the engines of cars. Numerous manufacturers produce dump valves for different applications, including custom designs made to specification for special uses. Individuals ordering custom valves can list a number of needed design features that will be used to develop a tool tailored for the job.

Tanker trucks can be fitted with dump valves.
Tanker trucks can be fitted with dump valves.

When released, a dump valve allows material to flow freely through it at a very rapid rate. Dump valves can be fitted on storage tanks to allow their contents to be released quickly, and they can also be used as a safety feature to relieve pressure or dump a load that is creating a hazard. Aircraft are fitted with dump valves that can be used to release fuel to lower landing weight, and valves are also fitted on the fuel manifold to drain it when the engine is off.

Air locks typically have dump valves that can be used to manage pressure in environments like spaceships and scientific facilities. The valves can be fitted with filters that are designed to trap particulates, and usually operate on a one way basis, allowing air and particles out, but not allowing exterior contaminants in. Such valves are also used to maintain safety in other pressurized systems, such as hydraulics.

Turbocharged cars are fitted with a dump valve to maintain safe levels of pressure in the engine. Air pressure can build up in the engine and when it is not used for energy, the dump valve can activate to allow the air to escape. This valve is also a one way design to ensure that dirt and other materials do not enter the engine when the valve activates.

Dump valves are usually clearly labeled with directions for their use so they can be quickly identified and used when necessary. They are often designed to be simple enough to use so people without formal training can safely activate them, ensuring that in an emergency situation where a technician or trained personnel are not available, a dump valve can still be used to relieve pressure or jettison a load. It is important to follow the directions of trained personnel during emergency situations, unless no one is available to provide guidance in how to respond to an emergency.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

You might also Like

Readers Also Love

Discussion Comments


@David09 - I haven’t heard of the urinal dump valve. I do know divers have an air dump valve mechanism that is attached to their body suits.

These are several different valves and they can be released as needed to adjust the buoyancy levels as divers descend into the ocean. These buoyancy compensators, as they're called, are what give the divers the ability to stay at certain depths in the ocean.

They can also use the equipment to ascend gradually instead of bobbing to the top all at once. Diving is all about balance, between the air in your tank and the buoyancy in the water.


The dump valve concept is extended in a variety of applications. Believe it or not, deep sea divers have something similar that will enable them to relieve themselves while underwater.

It’s a urinal dump valve, and it’s basically a one way valve that is attached to the diver’s body suit. Obviously I think it stands to reason that this is primarily for male divers, given the descriptions I’ve read of how the mechanism works, but who knows, maybe there is something similar for female drivers as well.

I would think of this kind of dump valve as an emergency mechanism, only to be used when you’re out diving for extended periods of time. After all, when you’ve got to go, you’ve got to go.

Post your comments
Forgot password?