# Pneumatics



## milk man (Aug 5, 2009)

Been relearning pneumatic. 

We have a school with an old pneumatic system. 

Space was over cooling. It had a humidistat and a thermostat.

Air lines where full of water:sad:

What I've found:

Hankinson air dryer's CFM not working, and compressor overload open.

One motor on compressor not working.

Tank pressure not raising above 10 psig.

Valved off tank and it built to 80 psig. I slowly opened the ball valve and bam, overcharged the lines. Regulator shot also.?

So what I think happened. CFM on dryer quit. Dryer compressor cycled on OL until it would not reset.

Regulator got wet and gave it up and overcharged lines.

Something in the building has a massive leak somewhere because the system will not charge above 6 psig now.

I converted the cooling to run off an electronic stat. Still need the air to open hot water coil's valves.

Need to:
Make sure the compressor will cycle off between 60 and 80 psig.
Repair/replace air dryer.
Repair/replace regulator.
Find out why I can't build pressure in system above 10 psig.
Add solenoid to water coil's valve.

Any thoughts?


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## jvegas (Jun 17, 2009)

milk man said:


> Been relearning pneumatic.
> 
> We have a school with an old pneumatic system.
> 
> ...


 maybe some bad diaphragms on some vales or some one cut some air lines above ceiling doing some other work :thumbsup:


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## KnightRider (Sep 11, 2009)

Lot's of problems there. Might be time to purchase new equipment. Is your dryer a refrigerant dryer or a desiccant type. Regulators are cheap. Your time shouldn't be.


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## milk man (Aug 5, 2009)

It's a Hankinson dryer

I have not had a chance to get back to the job.


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## KnightRider (Sep 11, 2009)

milk man said:


> It's a Hankinson dryer
> 
> I have not had a chance to get back to the job.


Yes well Hankinson makes refrigerant, desiccant and membrane dryers. If it is a refrigerant type then you could have a problem with the trap clogging on you. Should get a electric operated motor or solenoid valve to remove the water. Need more info on the equipment you got.


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## milk man (Aug 5, 2009)

KnightRider said:


> Yes well Hankinson makes refrigerant, desiccant and membrane dryers. If it is a refrigerant type then you could have a problem with the trap clogging on you. Should get a electric operated motor or solenoid valve to remove the water. Need more info on the equipment you got.


 
Don't know for sure.

I disassembled a float and cleaned it. Model number HPR10.


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## KnightRider (Sep 11, 2009)

milk man said:


> Don't know for sure.
> 
> I disassembled a float and cleaned it. Model number HPR10.


If you have a float trap then that is one of your problems. They won't work long before they get clogged with oil and dirt and won't open to drain water. either get a timed electric trap or have a small continuous bleed off the dryer so the water will get out.


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## milk man (Aug 5, 2009)

I went there today. Located three leaks. Replace the regulator and oil seperator filter.

Out of the dryer the copper lines go to three floors then turn to plastic. I capped each run and shut off the air to the building at the tanks ball valve. Each time I lost pressure in the lines. Is this normal? I thougth it would hold pressure. All the pneumatic stats where turned all the way down.

I set the regulator at 20 psig. The lines have around 17 psig and I can hear air going through the copper. There is one other small run and the guy working with me said he had check it and no leaks. 
__________________
Beware of advice given by some guy on the Internet.


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## Becks (Mar 1, 2012)

Any of the controls that were exposed to water need to be replaced. Are they Vav boxes with hot water reheat? It may be time to switch to ddc.


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