Yorhe 22 mm Heavy Duty Auto Bypass Valve YBV22

A lot of boiler manufacturers demand that the circulation of water through the boiler heat exchangers shouldn't fall below a certain limit, regardless of system load. The Yorhe YBV22 bypass valve opens and closes according to the system pressure  increasing the system efficiency as well as eliminating any noise.

This also allows for every radiator on the system to have a TRV.