A non-return valve permits a
medium to stream in only one way and is suited to make certain that the medium streams
due to a pipe in the right direction, where pressure circumstances may
otherwise cause transposed stream.
The stream during the non-return
valve causes a moderately greater pressure decline, which has to be taken into explanation
when planning the system.
Non-return
valves are for example used with combining loops in boiler and chilling systems
to make sure proper operation, and with domestic water systems to avoid backflowing.