What is the purpose of a back flow check valve?

A backflow check valve serves a critical function in plumbing and fuel systems by ensuring that fluid flows in only one direction. This is essential for preventing backflow, which can contaminate the main supply with substances from reverse flow. The design of the valve allows it to remain closed under normal circumstances and only open when fuel is intentionally flowing from the outside, thus protecting the integrity of the system and maintaining safety standards.

By allowing flow in only one direction, the backflow check valve plays a vital role in preventing issues such as cross-contamination and system malfunctions. It is designed specifically to manage the direction of flow rather than allowing unrestricted flow or filtering impurities in the gas, which are functions performed by other components. Additionally, it does not increase pressure inside the tank, as its primary role is directional control, not pressure manipulation.