Check valve is a self-acting valve type allowing forward flow or reventing reverse flow. Other terms used include back pressure valve, non-return valve, reflux and retention valve.
Operation Principle of Check Valve
Check valves are available with different spring rates to give particular cracking pressures. The cracking pressure is that at which the check valve just opens. If a specific cracking pressure is essential to the functioning of a circuit, it is usual to show a spring on the check valve symbol. The pressure drop over the check valve depends upon the flow rate; the higher the flow rate, the further the ball or poppet has to move off its seat and so the higher the spring force.
Review Of Some Of The Check Valve's Models
A check valve may be defined simply as a mechanical device typically used to let fluid, either in liquid or gas form, to flow through in one direction. They usually have two ports or two openings – one for the fluid entry and the other for passing through it. Often part of household items, they are generally small, simple, and inexpensive components. They also come in various sizes and costs. Following is a review of some of the models available in the market.