Fittings used at pressures higher than container pressure on the discharge of the liquid transfer pump should have a working pressure of at least what?

The correct answer reflects the importance of selecting fittings with a suitable working pressure to ensure safety and reliability in systems that handle pressurized liquids, such as propane transfer systems. Fittings used in the discharge of a liquid transfer pump must be able to safely manage pressures significantly higher than the container pressure.

In this context, having connections rated for 350 psig provides a necessary safety margin to accommodate the liquid transfer process, which typically entails dynamic pressure changes and potential fluctuations caused by the operation of the pump.

Using fittings with an appropriate working pressure, such as 350 psig, helps prevent failures that could result from excessive pressure, such as leaks or ruptures. It's critical in any gas transfer operation to adhere to applicable standards and safety guidelines, which dictate that fittings and components should be rated well above the operational pressures encountered during transfer operations.

Fittings rated below this level, such as those rated at 150 or 250 psig, may not provide sufficient safety or reliability under the conditions present during liquid transfer, thus underscoring the necessity for higher-rated fittings.