In many of our systems there is a header tank of approximately 1,000 litres which sits above the height of the main tank to provide extra pressure for additional tap outlets. This type of design is typically used in our school and community based systems to allow water to flow to several locations and across further distances, saving time and labour.
In order to allow the header tank to function properly and fill wih the minimum effort we needed a one way or non-return valve. Various manual options were considered and rejected due to the potential for operator error and vandalism.
In the end we decided on an automatic option that could be placed inside the tank to provide maximum protection. Turning to the local market we were able to find a solution that was reliable, easily serviced by the local people and cost effective. The one way valve (pictured covered during installation) allows the majority of the header tank to fill by gravity with only a small amount of pumping required for the final top up.