In order to maintain system design efficiencies and provide protection from transients, water pipelines and distribution systems require the installation of air valves at high points and regular intervals to exhaust and admit air during system operations including filling, draining, and critical conditions such as surges or line breaks.
A significant risk to public health exists when a drinking water distribution system is exposed to the negative pressure with possible entrance of contaminated water through the air valve.
CSA SUB series, available for the water, sewage and industry line of CSA air valves, are equipped with a threaded outlet connection to avoid the entrance of contaminants, in case of underground installations, reducing at the same time noise and spray effects coming from a possible rapid filling.