What is the main purpose of check valves in an LP-gas piping system?

The primary function of check valves in an LP-gas piping system is to prevent backflow within the system. This is crucial for maintaining the safety and efficiency of gas distribution. When a pressure differential occurs, check valves automatically close, stopping the gas from flowing back into areas where it shouldn't, which could lead to potential hazards such as leaks, contamination, or pressure problems.

By ensuring that gas flows in only one direction, check valves help maintain system integrity and allow for safe operation within the designed parameters of the LP-gas system. Properly installed check valves contribute to the overall reliability of the gas supply, making them an essential component in preventing unwanted conditions that could affect both equipment and overall safety.

While the other options include functionalities that may be relevant in different contexts, they do not apply to the specific role of check valves. For instance, allowing gas to flow in both directions would counteract the very purpose of a check valve. Reducing line pressure is typically managed by regulators and not check valves, and mixing different gases poses safety risks that check valves are not intended to address.