Koso EPC814 pneumatic actuator calibration

[Abhi]

I have pneumatic actuator of model EPC814 of KOSO and i want to calibrate it.

This actuator is connected to double acting cylinder. So please help me out. Actually its settings are out. So, feedback cam, zero and span setting is required. I have enclosed its pictures. Outlet 1 and outlet 2 of positioner is connected to two ports of the cylinder.

 

[gar]

180724-0921 EDT

Abhi:

I know nothing about the specific items you mentioned.

I believe you have two major components.

1. Some sort of mechanism that uses a double acting air cylinder to create rotation. Likely rotary motion of a limited range. Could be less than 90 degrees, but with a rack and pinion more than 360 degrees.

Based on the label the function is to produce torque.

If the purpose of this test is to determine a scaling factor for the mechanism, then part of the calibration procedure is to apply known torque levels to the actuator. This can be done with weights and a lever arm.

Air cylinders have a lot of friction. Therefore, there will be hysteresis.

2. To run the test the second item needed is an adjustable air source with a calibrated pressure gauge.

With respect to these comments what is your question?

.

 

[petersonra]

is there no instrument tech in your plant to do this kind of thing? It will require some calibration equipment that the tech should have.

 

[Ingenieur]

the actuator is 90 deg, likely for a valve
what is the input signal to the positioner: 4-20 mA, 3-15 psi ???

in general
get manual and variable signal source (could override controller)
put low sig in, adjust to almost 0, say 10%
adjust feedback unril valve is positioned at 0
put high signal in, adjust span to 100%
put low signal verify rtn to 0
verify 25, 50, 75 and 100

if controlled by a pid loop exact positioning is not critical
the pid will adjust output until measured variable = setpoint
who cares if pid is 50% and valve is 55%?

 

[Abhi]

The input signal to this positioner is 4-20 mA.

 

[petersonra]

The input signal to this positioner is 4-20 mA.

does the positioner move at all when your change the 4-20 mA signal?

 

[Abhi]

does the positioner move at all when your change the 4-20 mA signal?

It is moves according to the signal given. When 4ma is given valve shuts and if 20 ma given then valve opens. Valve 0° means close valve 90° means open

 

[petersonra]

It is moves according to the signal given. When 4ma is given valve shuts and if 20 ma given then valve opens. Valve 0° means close valve 90° means open

It appears that works why do you think it needs to be calibrated?

 

[Abhi]

It appears that works why do you think it needs to be calibrated?

Actually its calibration is out because i dismantled the actuator. When i assembled the actuator with positioner it was not working because its cam was moved