What is a check valve used for?

‘ The main purpose of a check valve is to prevent backflow in the system. Figure 1 shows an example of a check valve. A check valve relies on a pressure differential to work. They require a higher pressure on the input side of the valve than the output side to open the valve.

What is normal check valve?

Check valves are normally in the close position and open when the fluid flows through it. It also has the capability of shutting off the flow in the event the pressure downstream exceeds the upstream pressure. In this respect, it is used for flow in one direction only. Thus it prevents backflow through the valve.

What is a check valve on a water line?

Check Valves. Check valves allow flow in one direction only, and close automatically if flow reverses. They are completely automatic in action, depending upon pressure and velocity of flow within the line to perform their functions of opening and closing. You can install most Crane FS swing check valves in horizontal or vertical upward flow piping.

What is the working principle of a check valve?

Check Valve Working Principle A check valve requires a minimum upstream pressure (pressure differential between inlet and outlet), also known as cracking pressure, to open the valve and allow fluid flow through it.

What type of check valve do I need for compressed air service?

Compressed air service requires a horizontal lift check valve with a nitrile rubber facing on the disc and fitted with a recoil spring. The valve should always be installed as far away from the compressor as possible.

What is cracking pressure in a check valve?

Cracking Pressure – Refers to the minimum differential upstream pressure between inlet and outlet at which the valve will operate. Typically the check valve is designed for and can therefore be specified for a specific cracking pressure. Cracking pressure is also known as unseating head (pressure) or opening pressure.