Automatic valve assembly for water circulation systems

摘要

A filtration and backwash system for a water source such as a swimming pool is provided including a fluid source, a pump, a filter and a specially designed five-port valve which is easily adaptable for automatic use in the filtration mode and in the backwash mode. The valve uses a rotatable deflector plate which is positioned to divert the fluid in one direction in the valve for the filtration process and is positioned to divert the fluid in the other direction in the valve for the backwash process. An automatic timing device is also provided and is particularly suitable for use in conjunction with the valve whereby no manual intervention or electronic means is needed to change the valve from the filtering mode to the backwash mode or vice versa. The timing device automatically senses the pressure buildup in the filtration system due to accumulation of debris in the filter and automatically changes the valve from the filtration mode to backwash mode when a predetermined system pressure is exceeded. The timing device then gradually returns the valve to its initial filtering position to continue the filtering process.