Check valve flange type BA4760 DN60-65 149B3486

Backflow preventer – protection of the water supply network

This backflow preventer, type BA4760, is a key element protecting water installations from contamination caused by water backflow. Its construction, based on two check valves and an intermediate chamber, creates an effective barrier, preventing the mixing of media in the event of pressure changes. The device is particularly important where there is a risk of backflow, e.g., in connection with networks with different degrees of water purity.

Construction and principle of operation

The BA4760 isolator consists of a body made of epoxy-coated grey cast iron (or spheroidal graphite cast iron in larger diameters), a cover also made of epoxy-coated cast iron, and internal elements made of materials resistant to corrosion and water action – EPDM membrane, brass and stainless steel. The principle of operation is based on automatically cutting off the flow when backflow is detected. An air gap is created in the intermediate chamber, which physically separates the supply zone from the drainage zone. This effectively prevents the transfer of contaminants between different points in the installation.

Installation and application

Installation of the backflow preventer requires adherence to several rules. It is necessary to install a shut-off valve and a sediment filter before the device and another shut-off valve behind it. It is also necessary to provide a drain to the sewer to remove water collected in the intermediate chamber. The device should be mounted in a horizontal position, with the drain valve facing downwards and protected from frost and high temperatures. The BA4760 isolator is used in residential, industrial buildings and irrigation systems, wherever protection against backflow is required in accordance with PN-EN 1717 and PN-EN 12729 standards. Thanks to the nominal diameter of 60-65 mm and the connection length of 356 mm, this isolator is designed for use with pipes with appropriate parameters.