What type of valve is used to prevent sewage backflow from one pump to another?

The swing check valve is specifically designed to allow flow in one direction while preventing backflow, making it ideal for preventing sewage from flowing back from one pump into another. This type of valve operates using a hinged disk that swings open with the forward flow but closes off when flow reverses, thereby effectively stopping any potential backflow of sewage.

This functionality is crucial in sewage systems where backflow could lead to contamination, system failures, or hazardous situations. In contrast, the other types of valves mentioned serve different purposes. For example, a ball valve is primarily used for on/off control, a gate valve is better suited for isolation rather than preventing backflow, and a pressure relief valve is intended to relieve pressure in systems rather than control flow direction. This makes the swing check valve the most appropriate choice for ensuring that sewage does not reverse direction between pumps.