SPX FLOW W71, Instruction Manual, Page: 20 / 64

Operation Waukesha Cherry-Burrell Brand W71/W72RS Sch. 5 Mix Proof Valves
Page 20 95-03091 08/2018
Valve Operating
Conditions
See Figure 11 on page 17 for port and corresponding chambers.
Valve Open
The valve is open when Chamber 1 is pressurized and Chambers
3 and 2 are vented. See Figure 13.
Valve Closed
The valve is closed when Chambers 3, 1, and 2 are vented. The
large spring closes the valve to the fail safe position. See Figure
14.
Valve Closed, Upper Seat Lifted
For cleaning the upper seat on seat lifting models only. Chamber
2 is pressurized, and Chambers 3 and 1 are vented. See Figure
15.
Figure 13 - Valve Open
Figure 14 - Valve Closed
Figure 15 - Valve Closed, Upper Seat Lifted