MSA ASV automatic switch valve

For use when SCBA is combined with external air supply from a compressor (air-line) or pressure cylinder battery (e. g. for use in chemical-protective suits). If the pressure of the external air supply drops below 4. 3-5. 3 bar the valve changes automatically to the SCBA. If the pressure rises again in the external hose the air supply changes again to the external one. Working pressure for external supply 3. 5-10 bar. A single whistle signal, if the cylinder valve on the apparatus is closed, a second whistle signal, if the pressure drops in the external air supply.