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Submersible Check Valves Install: When Where & Why

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In a submersible pump application, check valves are critical to stop water from flowing downward in the pipe and returning into the well when the pump is turned off. To reduce the long-term risks and damage of a pump, we understand the critical importance of installing multiple check valves rather than just one check valve in submersible pump applications.

Proper Placement

Most high quality submersible pumps will have a check valve built in from the manufacturer at the discharge. This check valve will be the first check valve installed. The second check valve should be placed above the pump and no more than 25 feet above the water pumping level in a well. This will ensure that if the check valve at the pump fails, the second check valve in the system will hold the vacuum below it.

Think about a drinking straw in a glass of water. When you place your finger over the top of a drinking straw, you can lift the straw out of the glass and the liquid that was in the straw remains inside. The maximum range or length of straw that could hold water is roughly 32 feet at sea level. Anything higher than 32 feet cannot physically be held by the vacuum, thus the water would fall out of the straw. The same holds true in a submersible pump installation.

Above this initial valve, submersible check valves should be placed every 200 feet in the drop pipe as permitted by well depth. Outside the hole, many States require an additional check valve above ground that is commonly positioned near the pressure tank. For example, let’s look at a 750-foot-deep well with the water level at 700 feet. This situation requires a total of five or six check valves to be installed. The system will have a check valve positioned at the pump discharge followed by another at 675 feet deep. Above the installation of these valves there should be three more check valves installed every 200 feet on the drop pipe below ground putting them at 475 feet, 275 feet and 75 feet deep. The sixth and final check valve, if necessary, is positioned at the surface.

NOTE: The ideal recommended installation location for the first check valve is one pipe length above the submersible pump. A valve in this position will be subject to laminar flow and isolated from the very turbulent conditions near the pump discharge.

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