Do I need a non-return valve?
Non-return valves are used in systems where it is desirable to make sure fluids flow mostly in one direction, but may not be critical, for example in pumped systems such as heating circuits.
What is the difference between check valve and non-return valve?
A non-return valve lets the fluid flow in one direction. When fluid in the line reverses direction, a check valve prevents backflow by allowing flow in one direction. The check valves are usually designed for a particular pressure.
Do non return valves work?
Non-return valves work by allowing media to flow through them in only one direction. These valves have two openings in the body, one for media to enter and the other for media to leave. Non-return valves work automatically, which means that most are not controlled by a person or an external control.
What is another name for non-return valve?
A check valve, non-return valve, reflux valve, retention valve, foot valve, or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction.
Do non return valves fail?
However, even these valves tend to fail. Tero et al  showed that failure in the NRV can be detected by monitoring the shaft torque behaviour during the system shutdown and by comparing this instantaneous shutdown behaviour to separately stored reference behaviour for the pump.
Why non-return valves are used?
A non-return valve allows a medium to flow in only one direction and is fitted to ensure that the medium flows through a pipe in the right direction, where pressure conditions may otherwise cause reversed flow.
How many types of NRV are there?
There are two types of swing check valves. There are two types of swing check valves, the wafer type and the conventional swing check valves.
How does a butterfly valve work?
A butterfly valve is from a family of valves called quarter-turn valves. When the valve is closed, the disc is turned so that it completely blocks off the passageway. When the valve is fully open, the disc is rotated a quarter turn so that it allows an almost unrestricted passage of the fluid.