Pneumatic control valve

[Abdul03]

Dear Friends,

I have a project in which I am working on an existing chiller plant, It's complete pneumatic and a very old system. I have a control valve which is controlled by 3511 pneumatic rotary positioner.

It consists of supply air, input air (from instrument) and valve output. I applied supply air of 20 PSI and given a input signal of 3-15 psi using a pneumatic pump. I just don't knwo how to operate this valve. I am working on pneumatic controls for the first time. I appreciate if someone could able to help me to find a solution to this.

I hope there could someone who has good knowledge on pneumatic controls.

Thank you,

 

[gclshortt]

http://www2.spiraxsarco.com/resources/steam-engineering-tutorials/control-hardware-el-pn-actuation/control-valve-actuators-and-positioners.asp

Here is a link to a tutorial on Control Valve Actuators and Positioners.

Regards

 

[nonuke]

You probably have an I/P converter to control the valve.
If you send 4mA to the I/P, the I/P sends 3psi to the valve and the valve stays closed and if you send a 20mA signal, the I/P sends 15psi to the valve and the valve opens completely. the signal can also be inverted cool/heat but this is the idea.

 

[Mickey]

You probably have an I/P converter to control the valve.
If you send 4mA to the I/P, the I/P sends 3psi to the valve and the valve stays closed and if you send a 20mA signal, the I/P sends 15psi to the valve and the valve opens completely. the signal can also be inverted cool/heat but this is the idea.

Don't think so, see link. I cannot find a manual.

http://www.ebay.com/itm/Fisher-3511-Valve-Positioner-/331606307856?hash=item4d3546b410

 

[shooter]

the supply should be around 60 psi, as there is a strong spring in the valve.
on the valve stem is a lever going into the positioner.
i have seen a lot of wear on the o rings of the very small cylinder giving air to the ports.
internal is a flapper nozzle system to the lever.

i took out all positioners and put the instrument line on the valve direct.
outside the coldroom i took out all I/P converters and replaced them with 5/3 valve now i can give it a pulse to open or close the valve.
inside the room is only the valve.
take care to dry the air.

 

[nonuke]

You are correct Mickey. I guess I didn't pay attention to the post "3511 pneumatic rotary positioner".