Black or green connector knobs on Type 1 OPD service valves indicate?

The black or green connector knobs on Type 1 OPD (Overfill Prevention Device) service valves serve to indicate the flow rating of the valve. This color-coding system is designed to standardize the connection of propane tanks and help prevent improper refilling by providing visual guidance on the capacity and flow characteristics of the valve. It ensures that users can easily identify the appropriate equipment needed for safe and efficient operation.

Using the correct connector for a given appliance or refill procedure is essential for safety, as mismatched components could lead to systems not functioning properly or create hazards during operation. Understanding this coding system is crucial for those who handle propane tanks to ensure compliance with safety standards and regulations.