SPX FLOW W71, Instruction Manual, Page: 19 / 64

Waukesha Cherry-Burrell Brand W71/W72RS Sch. 5 Mix Proof Valves Operation
08/2018 95-03091 Page 19
Test Procedures
Positive Fail-Safe Detection Test
Perform a test to verify the fully closed fail-safe position. The
valve stem feedback proximity sensors should be set for the fully
opened and fully closed positions of the valve. See Figure 12 for
port and corresponding chambers.
Decommission the system, drain the lines and lock out the
pumps.
1. With the valve fully closed, confirm that the proximity sensors
conform to the tables on page 18. Verify the sensor status on
the PLC control system.
2. Pressurize air chamber 1 to open the valve. Confirm that the
proximity sensors conform to the tables on page 18. Verify
the sensor status on the PLC control system.
3. Vent air chamber 1 to close the valve.
4. If used, activate the upper seat lift either through the control
system or by supplying air to port 2.
5. When the upper seat lifts, confirm that the proximity sensors
conform to the values in the tables on page 18. If the yoke
area does not have a limit sensor, visually confirm the upper
seat lifting.
6. Vent the air in chamber 2 to deactivate the seat lift.
7. If used, pressurize air chamber 3 to activate the lower seat
push.
8. Confirm that the proximity sensors conform to the tables on
page 18. Verify the sensor status on the PLC control system.
9. Vent the air in chamber 3 to deactivate the seat lift.
10. Disconnect the air from the valve actuator, placing the valve
in the fail-safe position. Verify that the proximity sensors reg-
ister that the valve is fully closed.
Corrective Action
If the double seat Mix Proof valve fails to respond as indicated
above, immediately check the valve assembly and wiring to
locate and correct the cause:
• First, check the proximity sensor adjustment.
• Check for the correct assembly and adjustment of the valve.
• For specific information on sensor setting, please refer to
control module publication 95-03083.
1 = Valve Open Inlet Solenoid
2 = Upper Seat Clean Inlet Solenoid
3 = Lower Seat Clean Inlet Solenoid
Figure 12 - Solenoid Valve Port
Connections
VA100-093E
3
1
2