enblethen wrote:
OPD has a float valve as part of it. Good description in lower portion of this.
OPD valve
From your link.....
The new OPD valves prevent overfilling of gas cylinders,...... OPD valves solve this problem by using a special float (shown right) which rises during refilling to block the filling process when the tank is 80% full. From my link at Propane 101.....
The OPD valve is simply a protective device that, as the name implies, prevents overfilling of a propane cylinder.The OPD valve is only actuated during the filling process, not during operation..........it will not stop the flow of gas out of the cylinderOPD..stops filling at 80% liquid level but will not stop flow of gas out