Is a non return valve only used for mixer taps?

A non return valve is not only used for mixer taps. It can also be used in various plumbing and heating systems to control the flow of liquids or gases and prevent backflow. Here are some examples of where non return valves may be used:

1. Water supply lines: Non return valves can be installed in the incoming water supply line to prevent contaminated water from flowing back into the main water supply, ensuring the safety and quality of the drinking water.

2. Boilers and heating systems: Non return valves are often used in heating systems to ensure proper circulation of hot water and prevent reverse flow. This helps maintain the efficiency of the heating system and prevents damage to system components.

3. Sump pumps: In basement sump pump systems, non return valves are installed to prevent water from flowing back into the basement after the pump has discharged it. This is particularly important to prevent flooding in areas prone to water seepage or heavy rainfall.

4. Irrigation systems: In outdoor irrigation systems, non return valves help prevent siphoning and backflow of contaminated water into the potable water supply.

It's important to consult with a licensed plumber or water professional to determine the specific requirements and placement of non return valves based on local regulations and the plumbing system design.