The two methods for providing excess-flow protection and positive shut off of liquid at the withdrawal opening of ASME tanks typically used to supply propane dispensets

The two methods for providing excess-flow protection and positive shut off of liquid at the withdrawal opening of ASME tanks typically used to supply propane dispensets

• A. Electronic valve
• B. Manual valve with excess flow and internal valve with excess flow
• C. Manual valve with excess flow only
• D. Internal valve with excess flow only

Answer: (B)

When propane is withdrawn from an ASME tank, safety requires limiting the liquid flow to a safe rate and ensuring the flow can be stopped completely. There are two common ways this excess-flow protection is built into the tank’s withdrawal system. One uses a manual valve equipped with an external excess-flow device, so the operator opens the valve and the excess-flow mechanism automatically throttles or stops the flow if it tries to exceed the safe rate. The other uses an internal valve assembly inside the tank that already includes the excess-flow protection, providing the same automatic control right at the source. Both configurations deliver the needed excess-flow protection and positive shut-off, which is why this option reflects the typical, practical setups used for dispensing propane. Electronic valves are not the standard approach for these tanks in this application.

When propane is withdrawn from an ASME tank, safety requires limiting the liquid flow to a safe rate and ensuring the flow can be stopped completely. There are two common ways this excess-flow protection is built into the tank’s withdrawal system. One uses a manual valve equipped with an external excess-flow device, so the operator opens the valve and the excess-flow mechanism automatically throttles or stops the flow if it tries to exceed the safe rate. The other uses an internal valve assembly inside the tank that already includes the excess-flow protection, providing the same automatic control right at the source. Both configurations deliver the needed excess-flow protection and positive shut-off, which is why this option reflects the typical, practical setups used for dispensing propane. Electronic valves are not the standard approach for these tanks in this application.