When LP-gas liquid can be isolated between shutoff valves, what type of valve is required for each closed section of piping?

In the context of isolating LP-gas liquid between shutoff valves, each closed section of piping requires a specific type of valve to ensure safe handling and maintenance. A hydrostatic relief valve is designed to relieve excess pressure that may build up within a closed section of piping, which is essential when dealing with LP-gas. During normal operations, if the temperature increases, the liquid LP-gas could expand, leading to an unsafe rise in pressure. The hydrostatic relief valve serves to automatically release gas and prevent overpressure situations, thereby protecting the piping system and related components.

This valve is critical for safety and is mandated in instances where LP-gas liquids are isolated. In contrast, the other types of valves serve different purposes: manual shutoff valves are used to manually isolate the flow of gas for maintenance or emergencies, while pressure relief valves are designed to engage at set pressure thresholds but may not function in the same manner as hydrostatic relief valves specifically for liquid isolation. The emergency shutoff valve is also intended for emergency situations, but does not take the place of a hydrostatic relief valve in maintaining safe operating conditions in isolated sections of liquid piping.