An OPD serves as a ______.

An OPD serves as a ______.

• A. Primary safety valve
• B. Secondary means of preventing overfilling of cylinders
• C. Pressure Regulator
• D. Seal Integrity Indicator

Answer: (B)

Overfilling propane cylinders is a serious hazard because gas expansion can lead to venting and pressure buildup. The device in question is designed specifically to prevent that by automatically shutting off the fill once the cylinder reaches about 80% of its water capacity. That function makes it a safeguard used alongside other safety features, serving as a secondary measure to stop overfilling before the cylinder reaches dangerous pressure levels. This isn’t the same as a pressure regulator, which is used after filling to reduce pressure for safe use, nor is it a seal integrity indicator, which would only show whether a seal is compromised. It also isn’t the primary safety valve, which is a relief mechanism that vents if pressure gets too high. The key point is that the Overfill Protection Device actively limits how full a cylinder can become, providing a dedicated check against overfilling.

Overfilling propane cylinders is a serious hazard because gas expansion can lead to venting and pressure buildup. The device in question is designed specifically to prevent that by automatically shutting off the fill once the cylinder reaches about 80% of its water capacity. That function makes it a safeguard used alongside other safety features, serving as a secondary measure to stop overfilling before the cylinder reaches dangerous pressure levels.

This isn’t the same as a pressure regulator, which is used after filling to reduce pressure for safe use, nor is it a seal integrity indicator, which would only show whether a seal is compromised. It also isn’t the primary safety valve, which is a relief mechanism that vents if pressure gets too high. The key point is that the Overfill Protection Device actively limits how full a cylinder can become, providing a dedicated check against overfilling.