Dear Arthur, We have our model 5080 Hygrocal which is an automatic hygroscopic air vent with a manual operation mode. This provide automatically vent air from the system with the protection of the hygroscopic discs which shut down when in contact with water. With the manual operation mode you can manually purge air from the system at the location.
Dear Arthur, We have our model 5080 Hygrocal which is an automatic hygroscopic air vent with a manual operation mode. This provide automatically vent air from the system with the protection of the hygroscopic discs which shut down when in contact with water. With the manual operation mode you can manually purge air from the system at the location.