Vetus vacuum valves are designed to add ventilation to waste water holding tanks. This is an essential safety feature for when tanks are being emptied by powerful pumps. If an insufficient amount of air enters the tank through the vent line, the pumping process could cause the tank to implode. Vetus vacuum valves will prevent this, as it automatically opens as the vacuum pressure increases, and it allows air into the tank.
The Vetus vacuum vents are essential for your waste water tank if the vent line is smaller than 19mm diameter, or if the tank holds over 400 litres and has a vent line of less than 38mm diameter. The vents are made from synthetic materials and will not corrode.