Siemens SIPART PS2 Service Manual

Troubleshooting Procedures
3.6 Change in Valve Stroke
PS2 Troubleshooting Guide
20 Service Manual, 03/2017, A5E36661550-AA
3.6
Change in Valve Stroke
Process Build Up
Process materials can build-up on valves and valve seats. This can prevent a valve from
fully closing, and cause the process to leak through the valve. Additionally process build-up
can prevent the valve from fully opening.
To identify this:
● Put PS2 in Manual mode- from Auto, press button once.
● While pressing and holding
button, press and hold button. This will move the valve
to an end-stop position. To move valve in opposite direction, reverse push button
sequence; while pressing and holding
button, press and hold .
● 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)
One end-stop position should show full supply pressure. The other end-stop position
will show zero pressure.
–
For double-acting (two airlines to actuator)
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.
● If PS2 can output full supply and exhaust in both directions, then something else is
preventing actuator from fully closing or opening.
● Verify supply pressure is properly set, see Insufficient Supply Air.
● If valve is still not able to fully close or open, then check actuator/valve for:
– Mechanical binding
– Valve seat wear

Siemens SIPART PS2 Specifications

General

Supply Pressure	1.4 to 7 bar (20 to 100 psi)
Enclosure Rating	IP66/NEMA 4X
Communication Protocols	HART, PROFIBUS PA, FOUNDATION Fieldbus
Output Pressure	0 to 100% of supply pressure
Hazardous Area Certification	ATEX, IECEx, FM, CSA
Type	Electropneumatic
Input Signal	4-20 mA
Rotation Angle	30° to 90°
Operating Temperature	-40°C to +80°C
Mounting	Linear and rotary actuators
Air Consumption	Typically less than 0.1 kg/h