Foot Valves

A foot valve is a form of check valve installed at the bottom, or foot, of a suction line. When the pump stops and the ports of the foot valve close, the liquid cannot drain back to the suction well if the valve seats tightly. Foot valves were very commonly used in early installations of centrifugal pumps. Except for certain applications, their use is now much less common.

A foot valve does not always seat tightly, and the pump occasionally loses its prime. However, the rate of leakage is generally small, and it is possible to restore the pump to service by filling and starting it promptly. This tendency to malfunction is increased if the liquid contains small particles of foreign matter, such as sand, and foot valves should not be used for such service. Another disadvantage of foot valves is their unusually high fric-tional loss.

The pump can be filled through a funnel attached to the priming connection or from an overhead tank or any other source of liquid. If a check valve is used on the pump and the discharge line remains full of liquid, a small bypass around the valve permits the liquid in the discharge line to be used for repriming the pump when the foot valve has leaked. Provision must be made for filling all the passageways and for venting out the air.

Survival Treasure

Survival Treasure

This is a collection of 3 guides all about survival. Within this collection you find the following titles: Outdoor Survival Skills, Survival Basics and The Wilderness Survival Guide.

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