Can an OPD valve be relied upon for accurate filling of a DOT cylinder?

The assertion that OPD (Overfill Prevention Device) valves are not an approved method for accurately filling DOT (Department of Transportation) cylinders highlights important safety and regulatory considerations. OPD valves are primarily designed to prevent overfilling and to ensure the safe operation of gas cylinders. They function as a safety measure rather than a precise metering device.

The filling process of DOT cylinders must comply with strict regulations that ensure the integrity and safety of the cylinder, including precise measurements and weight specifications for the gas being filled. While OPD valves contribute to safety by preventing overfills, they do not guarantee that the filling process adheres to the exact specifications required for accurate gas measurement.

Accurate filling typically involves the use of calibrated equipment specifically designed for measuring gas volumes or weights, ensuring compliance with safety regulations and accuracy standards. Therefore, relying solely on an OPD valve for filling would not meet the necessary accuracy requirements mandated by safety regulations.