Which devices should not be installed between a container and a pressure relief device?

Which devices should not be installed between a container and a pressure relief device?

• A. Expansion joints
• B. Shutoffs and check valves
• C. Gas meters
• D. Pipes and fittings

Answer: (B)

The reason shutoffs and check valves should not be installed between a container and a pressure relief device lies in the fundamental safety roles these components play within a gas distribution system. A pressure relief device is designed to ensure safety by releasing pressure when it exceeds a specified limit. If shutoff valves or check valves are present, they can potentially prevent this critical safety device from functioning properly during an overpressure situation. Shutoff valves can completely isolate the pressure relief device from the container. If excessive pressure builds up and the relief device is unable to execute its function due to being blocked by a shutoff valve, there is a significant risk of catastrophic failure. Similarly, check valves are designed to prevent backflow, which could also obstruct the necessary operation of the pressure relief device when it is needed most. In contrast, expansion joints, gas meters, as well as pipes and fittings can be included in the system without significantly undermining the safety mechanisms in place. Expansion joints accommodate thermal expansion and contraction within the system, while gas meters measure flow without obstructing safety devices. Pipes and fittings are essential for connecting various components in a gas system. Their roles do not interfere with the operational integrity of pressure relief devices, making them acceptable for installation in that location.

The reason shutoffs and check valves should not be installed between a container and a pressure relief device lies in the fundamental safety roles these components play within a gas distribution system. A pressure relief device is designed to ensure safety by releasing pressure when it exceeds a specified limit. If shutoff valves or check valves are present, they can potentially prevent this critical safety device from functioning properly during an overpressure situation.

Shutoff valves can completely isolate the pressure relief device from the container. If excessive pressure builds up and the relief device is unable to execute its function due to being blocked by a shutoff valve, there is a significant risk of catastrophic failure. Similarly, check valves are designed to prevent backflow, which could also obstruct the necessary operation of the pressure relief device when it is needed most.

In contrast, expansion joints, gas meters, as well as pipes and fittings can be included in the system without significantly undermining the safety mechanisms in place. Expansion joints accommodate thermal expansion and contraction within the system, while gas meters measure flow without obstructing safety devices. Pipes and fittings are essential for connecting various components in a gas system. Their roles do not interfere with the operational integrity of pressure relief devices, making them acceptable for installation in that location.