restschool.blogg.se - Cc check valve vs ips

Swing Check Valve – The closure member swings about a hinge, which is mounted outside the seat.

Few basic and most used types of check valves are listed and detailed out below: Types of Check ValvesĬheck valves may be grouped according to the way the closure member moves onto the seat. The back pressure pushes the closing mechanism (a gate, ball, diaphragm, or disc) against the orifice and seals it.

Depending on the check valve design, the closing mechanism can change and the closing process can be assisted by a spring or gravity.

If the upstream pressure ever falls below the cracking pressure or there is a back pressure (flow attempting to move from the outlet to the inlet), then the check valve will close automatically. Check Valve Working PrincipleĪ 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. Reseal pressure is also known as sealing pressure, seating head (pressure) or closing pressure.īack Pressure – Refers to the pressure differential between the inlet and outlet of the check valve when the pressure is higher at the outlet of the valve than that at the inlet or a point upstream of the valve. Reseal Pressure – Refers to the pressure differential between the inlet and outlet of the valve during the closing process of the check valve, at which there is no visible leak rate. Cracking pressure is also known as unseating head (pressure) or opening pressure. Typically the check valve is designed for and can therefore be specified for a specific cracking pressure. Few Important Technical Terminologies Used in Check Valve Operations Ĭracking Pressure – Refers to the minimum differential upstream pressure between inlet and outlet at which the valve will operate. Use of check valve is particularly important in the case of pumps and compressors, where back flow could damage the internals of the equipment and cause an unnecessary shutdown of the system and in severe cases the complete plant. When the flow reverses, the valve closes automatically. When the flow is moving in the proper direction, the valve remains open. For this reason, check valves are installed in pipelines to prevent such a back flow and to permit the flow of product in only one direction. Flow reversal in fluid-handling systems is possible and can be caused by accidentalĮquipment stoppage or automatic fail-safe devices.