air intake valve

During my work, I experience more and more places, even in new residential buildings, that craftsmen forget to install the air intake valve, or they forget to ventilate the sewer. The air intake valve is a plastic part worth a few thousand forints. Its weight and size are negligible, but its function provides a huge help in maintaining home hygiene and maintaining a sense of comfort. The air intake valve is located in the drain pipe on the one hand…