This week I participated in an on-line discussion regarding a new “telltale indicator” that is being used in refrigeration processes. A really neat device that will indicate when an RV has lifted; however, I questioned its design and whether or not it could be considered an “obstruction” in the RV vent line. This device has a “paddle” type device that swings when moved by the pressure flowing through the device. The paddle is hinged on a bar that passes through the vent space.
Butterfly valves and relief valve line isolation
