‘Air’ on the Side of Caution

Kevin Marois

I recently looked at a dry cleaning machine that had a problem with the still. One of the valves was sticking open and the pre-separator would not drain. The valve for the vacuum pump would not close off tight. The air cylinder on the valve was full of rusty water and it would stick instead of moving smoothly.

Valve with rusty water.

When I disassembled the valve some rusty water ran out. The water had flushed all the lubrication out of the valve. It wasn’t an expensive repair but it caused a major interruption in production.

The worst part about this problem is that all the other valves have been exposed to water as well. It will only be a matter of time until they begin to malfunction.

A refrigerated air dryer could have prevented this problem. Most people don’t understand and are not willing to spend the money to install one.

How an air dryer works

Air hoses are for air, not water

Your air compressor draws in air from the plant and stores it under pressure in a tank. That air contains the same amount of moisture as the air in your plant – except it is more concentrated because it is compressed. As the air in the tank cools, the water may condense back into liquid form.

That water may travel through the air lines and into your machines. It may cause rust in some components. It may cause aluminum to corrode and form a paste that glues things together. Or it may just flush the lubrication out of your valves and cylinders.

This moisture may not bother some of your older equipment, but it can do a lot of damage on the newer machines.

Do you need one?

Filter bowl on air regulator spurting water when loosened.

You may drain your compressor every day – that’s great – but doing that only removes the liquid water from the air tank. You may also have filters on each machine, but those filters only remove about 10% of the moisture in the air.

Dry cleaning machines and shirt units are the most susceptible. They all have valves and cylinders that need to fire in a precisely timed sequence. When a valve or a cylinder sticks, your arms may be slow to drop or you may lose vacuum in your still.

An air dryer needs to be installed in a cooler area (not in the boiler room). It uses a fan to cool its refrigeration coil, so the cooler the area the better. The air dryer cools the air enough that the water condenses back to liquid and can be removed from the air.

I recommend it

Refrigerated air dryer

I would recommend installing an air dryer to reduce your maintenance costs; it will also improve the way your machines operate.

If you are already having problems caused by moisture in your air, I would urge you to get an air dryer as soon as possible. But understand that installing an air dryer today will not undo the damage that has already occurred.

When you have your air dryer installed, it might be a good idea to have your mechanic check the various places water could have begun to cause problems – and solve them before they become worse. What’s worse? Days without productivity that could have been prevented.

Kevin Marois founded Calgary-based Integrity Mechanical in 2003 to service plants in western Canada. He writes on issues related to equipment, its purchase, maintenance and use. You can reach Kevin at office@imicanada.ca or via his website www.imicanada.ca

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