Non-return valve 1 ¼"

The spring-loaded non-return valve ensure that once water has passed through it cannot flow back due to the internal diaphragm closing.

Generally, if it is not possible to use a suction hose with a suction strainer, the non-return valve is mounted to the suction connection of a self-priming pump (for example, a garden pump / booster pump). In that case, the valve stops the drawn-in water from flowing back to the source. In this set-up, the way it works can be compared to drinking from a glass with a straw, when you suck water through a straw and then place your finger over the end of the straw it holds the water in place.

Both sides of the non-return valve have a 1 ¼" screw connection fitted with a female thread.