 |
 |
 |
 |
 |
 |
 |
|
 |
 |
|
How does an OPD Valve function? |
||
 |
 |
|
| This diagram illustrates liquid
propane (navy blue) filling a cylinder through the OPD Valve. |
At a safe filling level, the float
cam (yellow) triggers the pin (orange) to fall into the recess of
the cam, sealing this path off and preventing any more liquid propane
from flowing through the lower valve body into the cylinder. |
|
 |
 |
 |
| The propane builds up pressure
in the chamber (center spring) and pushes the piston up to form
a seal, effectively stopping the filling process. |
The use of the propane from the
cylinder allows the OPD to reset itself for the next fill. |
|
 |
The OPD will help reduce the potential for the overfilling
of propane cylinders, thus reducing the possibility of hydrostatic
relief valve discharges. The OPD is the result of extensive research and testing. It is very reliable when used as a back up device to correct filling procedures. NFPA 58 states two methods of filling proper cylinders: weight, or volume measured by fixed liquid level gauge. (See NFPA 58 Section 4-5.) |
How to identify an OPD Valve
 |
 |
