The valves and fittings required by NFPA 58 for ASME tanks typically used to supply propane dispensers include a double backflow check filler valve, a spring-type relief valve, a fixed maximum liquid level gauge, and a _______.

• A. Dip Tube
• B. Thermocouple
• C. Pressure Gauge
• D. Float Gauge

Answer: (D)

NFPA 58 outlines the safety and level-indication devices needed on ASME propane tanks that feed dispensers. Along with a double backflow check filler valve to prevent contamination and a spring-type relief valve for overpressure protection, the system uses a fixed maximum liquid level gauge to show the highest safe fill level. The float gauge then provides a real-time reading of the actual liquid inside the tank, allowing the operator to monitor how full the tank is and to avoid overfilling. A dip tube is part of the withdrawal path rather than a level-indicating device, a thermocouple is for sensing temperature rather than level, and a separate pressure gauge isn’t the specified level-indicating device in this context. The float gauge best fits the role of giving continuous, immediate indication of the liquid level alongside the fixed maximum gauge.