What is the working principle of the foot valve

Update:26-05-2021
Summary:

Since foot valves are continually submerged in the wet […]

Since foot valves are continually submerged in the wet well and not readily accessible for inspection or repair, it is important to select a foot valve of high quality long wearing construction with the appropriate material to suit your application. In this article, Linquip has compiled useful information on PVC foot valves. So follow this new blog to expand your knowledge about these types of valves and their application.This foot valve is a type of check valve that is typically installed at a pump or at the bottom of a pipe line.  These foot valves act like ball check valves, but have an open end with a shield or screen over it to block debris from entering the line.

 

The valve opening is designed to be larger than the line itself, minimizing head loss.They can be found in ponds, pools and even industrial applications where PVC is a suitable material. These special valves allow the pump to stay primed, letting liquid to flow in, but keeping it from flowing back out. The screens or baskets that cover the valve opening tend to get clogged over time, especially in ponds and wells. It is important to check and clean your valves regularly for optimum performance.PVC foot valves have the same design as other foot valves and consist of the main valve body and line connection, the ball, the seal carrier, the seal, and the screen.

 

The good point is this valve can be fully disassembled for cleaning.When the pump is operating, there is suction created that sucks the water up through the pipe. The foot valve opens as water flows upward because of the pressure from the incoming water.When the pump is shut off, the upward pressure will stop. When this happens, gravity will go to work on the water that remains in the pipe, trying to cause it to move in a downward direction back into the well. However, the foot valve prevents that from happening.

 

The weight of the water in the pipe pushes down on the foot valve. Because the foot valve is unidirectional, it doesn’t open in the downward directions. Instead, the pressure from the water closes the valve tightly, which prevents any reverse flow back into the well and from the pump back to the sump.Foot valves usually come with surge blocks. A surge block is a tool used to press the body of a valve to remove the residues that may block smooth flow of water within the pump during operation. It also helps the valve expand while being used, thus enabling the presence of increased pressure without causing damage to the valve itself.