Troubleshooting Procedures; Actuator Blow-By (Double-Acting Only); Actuator End-Stops - Siemens SIPART PS2 Service Manual

Troubleshooting Procedures

3.1

Actuator Blow-By (double-acting only)

This issue is found only with double acting applications that are utilizing both Y1 and Y2
output ports.
● One output increases air pressure while the other exhausts air pressure
● This creates the necessary differential pressure in the actuator to move the valve.
● The two air chambers in the actuator must be isolated from each other; otherwise the
differential pressure cannot increase.
● The actuator has an internal leak, and requires servicing if:
– When trying to move the valve to a new position, air is continuously blowing out from
– When trying to move the valve to a new position, the two output pressures gauges, Y1
3.2

Actuator End-Stops

Actuator end-stops are adjustable, and must be set correctly for each valve application. If not
set correctly the actuator will drive the valve too far into the valve seat, or over rotate the
valve in the opening position. This can damage the valve and cause poor process
performance.
To identify improper end-stop settings:
● Review actuator/valve manual and determine proper end-stops settings for valve.
● Put PS2 in manual mode:
– From Auto press
– Use
● Using
valve is seating properly.
● If necessary make adjustments to actuator end-stops, refer to actuator's service manual
for details.
● Re-initialize PS2, see Initialization Procedure (Page 50) (see Appendix A).
PS2 Troubleshooting Guide
Service Manual, 03/2017, A5E36661550-AA
the exhaust port.
& Y2, are relatively equal in pressure value.
button once.
and/or to change valve position
and/or buttons move valve to both end-stop positions, and determine if
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