Suitable for heating systems and other hot water systems (not potable water), which require the efficient automatic removal of air from water The vacuum break on the bottom of the valve prevents an air lock forming and encourages air to be released from water Integral stop valve, enables seat to be cleaned without draining the system down Simple service and cleaning Expanding discs under cap prevent leaks due to dirt under the seat A 1/8in. to 1/2in. BSP adaptor supplied for connection to 1/2in. BSP female tee