DeZURIK
APCO CSV-1600 Surge Check Valves
D12022
Page 6
January 2013
Operation
The Surge Check Unit 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 unit, 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 its 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 and immediately have full re-entry flow of air into the pipeline before a
vacuum can form.
Drawings
NO
DESCRIPTION
1
Body
2
Seat
3
Plug
4
Spring
5A
Bushing
5B
Retaining Ring
6
Seat Retaining Ball
7
Seat Retaining Screw
Figure 1: CSV-1600 Surge Check Valve
