Siemens SIPART PS2 Service Manual page 23

Valve Seat Wear
Valve and valve seat wear can cause over-travel and process leaks.
To Identify this:
● Put PS2 in Manual mode- from Auto, press
● While pressing and holding
to an end-stop position. To move valve in opposite direction, reverse push button
sequence; while pressing and holding
● Use this two-push button method to drive valve fully open and fully closed.
● Utilize pressure gauges to determine if PS2 is outputting full supply pressure and
exhausting all output pressure.
– For single-acting (one airline to actuator)
– For double-acting (two airlines to actuator)
● If PS2 can output full supply and exhaust in both directions, then something else is
preventing actuator from fully sealing to valve seat.
● Verify supply pressure is properly set, see Insufficient Supply Air (Page 28).
● If process is still leaking through valve, check actuator/valve for:
– Mechanical binding
– Process build-up
PS2 Troubleshooting Guide
Service Manual, 03/2017, A5E36661550-AA
One end-stop position should show full supply pressure. The other end-stop position
will show zero pressure.
One end-stop position should show full supply pressure, while the other gauge should
show zero pressure. Output pressures will be reversed when driving valve to other
end-stop position, see following example of double-acting pressure gauges at each
end-stop position.
button once.
button, press and hold
button, press and hold
Troubleshooting Procedures
3.6 Change in Valve Stroke
button. This will move the valve
.
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