Inline check valve

An inline check valve is a one-way valve installed in a pipe that allows water to flow in one direction only, preventing reverse flow that could contaminate the supply or damage equipment. UK check valves are manufactured to BS EN 13959 and are commonly used on pump installations, mixer showers and the boundary between potable and non-potable water systems. The Water Supply Fittings Regulations 1999 specify the categories of check valve required for different risks of backflow. Common designs include spring loaded, swing and double check valves. They are used in conjunction with isolation valves to protect drinking water quality. Worn or sticking valves can lead to noisy operation and water hammer and should be replaced rather than disassembled and reused.