proportional valve test

we had a problem with our system that i'll explained to you as followed:
i worked in the tunneling job.our excavation have stoped before yesteday becouse we had a alarm so-called(cutting wheel brake pressure switch)and it shows us its brake engaged and it sence by a proximity switch.for new excavation this alarm should was released.
in accordance with the plc programm.potentiomete wich belong cutter head speed dosnt worked that with its turning we could adjust cutting wheel speed.potentiometer sent its data to plc and plc it sent to analog amplifier(vt 3000) and then it after command used for control of pilot proportional valve .so we checked our system step by step.
1-checking of pressure
2-checking of potetiometer
3-checking of analog amplifier
4-checking of propotional valve magnet by direct 24 v
5-opening of proximity switch
when we open the proximity switch we observed oil around it.it was damaged.now,our client claimed your test for valve wasnt corect becouse plc output was out of service .this during we dont turn the cutterhead.while we claimed cutter head brake has been leakage and couse our proximity switch damaged.so any body could help me which idea is correct? our test for propotional valve was correct or no?

thank you bahman

What exactly are you asking? For us to troubleshoot your complex system by interpreting your code-scribble?
Be more precise if you want people to understand your situation.

bahman,
Your test for the proportional valve (applying 24 volts directly to it) proves that it will move, but not that the analog amplifier between the potentiometer and the valve is working. The valve may only go from closed to 100% open, with no stops possible in between, if the amplifier is damaged.

I saw this very problem recently during the Christmas holidays, on the gas valve for a burner. When the control power was turned on, it went from closed to open, but would not respond to a 12 milliamp control signal and stop midway. The burner could not be controlled.

Your client is correct. Your test only proved part of the system. The client wants a complete working system, not merely a proportional valve that responds to an outside voltage. To check your proportional valve, you should go into the PLC program and manualy set the output and then check to see that the analog amplifier is responding with the correct signal to the valve. The only way to prove that a system works is to test the system, not individual parts. The whole system must work together.

How is the valve control related with the original problem of the cutting wheel brake proximity switch? If the brake proximity switch is damaged, replace it and go on to the next problem.

It seems the real problem is a "turf battle". There is a conflict about who knows enough about this equipment to work on it. Until that conflict is resolved and all parties are working together to solve the problem, you will not get very good results. Often in troubleshooting, no progress is made until egos and personalities are reigned in and controlled.

troubleshooting test

I have tested for the proportional valve (applying 24 volts directly to it) which its magnet is ok or no?, while the analog amplifier between the potentiometer and the valve is working.the output this valve feed some valves for turning cutter head.if we have pressure relief valve in the way.i have this question for you if we applyed 24 volts to propotional valve for testing of its magnet without analog amplifier card operation and during
my test only proved part of the system.

There is a conflict between our client and us to work on it.our client say without care input plc why you enargized it directly? please help me which is correct?

troubleshooting test

troubleshooting test
I have tested for the proportional valve (applying 24 volts directly to it) which its magnet is ok or no?, while the analog amplifier between the potentiometer and the valve is working.the output this valve feed some valves for turning cutter head.if we have pressure relief valve in the way.i have this question for you if we applyed 24 volts to propotional valve for testing of its magnet without analog amplifier card operation and during
my test only proved part of the system.

There is a conflict between our client and us to work on it.our client say without care input plc why you enargized it directly? please help me which is correct