There are, however, three problems. One, check valves are prone to jamming in the open position, thereby becoming an uncheck valve of sorts. Two, they are prone to jamming in the closed position, preventing water flow in any direction. And three, they can restrict water flow.

Does a dual check valve reduce pressure?

A double check valve or double check assembly (DCA) is a backflow prevention device designed to protect water supplies from contamination. ... Secondly the closure of one valve reduces the pressure differential across the other, allowing a more reliable seal and avoiding even minor leakage.

What does a double check valve do?

The double check valve only allows water to flow through in one direction, therefore, preventing backflow of potential contaminants. To install, simply push the valve fully on to the pipe.