DeZurik APCO AVV-140 Manual de instrucciones - Página 7
Navegue en línea o descargue pdf Manual de instrucciones para Unidad de control DeZurik APCO AVV-140. DeZurik APCO AVV-140 13 páginas. Air/vacuum valve with optional csv surge check valve
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DeZURIK
APCO AVV 140/150 Air/Vacuum Valve with Optional CSV
Surge Check Valve
Operation
The Air/Vacuum Valve operates normally allowing air to escape freely at any velocity (maximum
discharge velocity is approximately 300 feet per second (102 meters per second) at 6.7 psi (50KPa);
however, good pipeline design restricts velocity flows of air to 100 feet per second (34 meters per
second) which occurs at approximately 1 psi (7KPa)).
The Surge Check Valve operates on the interphase between the kinetic energy in the relative velocity
flows of air and water. The Surge Check is a normally open valve, spring loaded, so that air passes
through unrestricted. When water rushes into the Surge Check Valve, the disc begins to close against
the spring tension and reduces the rate of flow of water into the air valve by means of throttling holes in
the disc. This ensures normal gentle closing of the Air/Vacuum Valve regardless of the initial velocity
flows involved and minimizes pressure surges when the valve closes.
As soon as the Air/Vacuum Valve is closed, the pressure on both sides of the Surge Check Valve disc
equalizes and the disc automatically returns to the open position. This means the Air/Vacuum Valve
does not need an incipient vacuum to open, but can open at any time the water level drops and line
pressure approaches atmospheric. This allows immediate full re-entry flow of air into the pipeline before
a vacuum can form.
June 2019
Page 7
D12021