What type of valve ensures no backflow occurs in a container appurtenance?

The backflow check valve is specifically designed to prevent the reverse flow of liquid or gas within a system, which is crucial for maintaining system integrity and safety. These valves automatically close when there is a difference in pressure that could cause backflow, ensuring that the contents of a container do not flow back into the supply line or surrounding environment.

This type of valve is essential in applications involving LP-gas systems, as it helps prevent contamination of the gas supply and protects equipment from potential malfunctions that could arise from backflow scenarios. The backflow check valve allows flow in one direction while providing a reliable barrier against any unwanted reverse flow.

In contrast, a shutoff valve is primarily used to completely stop the flow of gas or liquid in a line but does not provide the specific backflow prevention functionality. An excess-flow valve is designed to close when the flow exceeds a certain threshold, ensuring that excess amounts do not escape, while a flow control valve regulates the flow of a fluid but does not focus on preventing backflow.