Condensate is a problem in your air lines, for all kinds of reasons. Free water and water vapor in your air lines could cost you a small fortune.
Thousands of dollars can be spent in maintenance to downstream air valves, air cylinders, air motors - all kinds of air operated actuators and equipment that are damaged by compressor created condensate and water vapor in your compressed air stream.
Here are some of the problems and how they can affect your air, your air-lines, and the tools, valves and actuators that you use in your plant.
But, free water is not all that could end up in your air-lines and into your air tools, valves and cylinders as a result of the water created by compressing your air.
That's the main reason why you should plumb your drop legs from the top of the air mains. That will, at least, reduce the flow of liquid into the drop leg.
It is when your equipment has been idle for a while, and that rust slurry dries, that the problems really start as your valves stick, insides of your cylinder barrels score with the abrasive rust, and so on. Rust is a real problem created by water in your black pipe air mains.
Despite the best efforts of air / oil separators lubricating oil gets into the tank and then the air line. If the compressor has seen significant use, older piston types in particular, the amount of oil that carries over to your compressor tank, and from there into your air lines, grows.
Unless your compressor is an oil-less type, meaning that in this type of compressor typically no oil contacts the compressed air, lubricating oil inside the compressor will inevitably make it onto the compressed tank and then into the lines.What is the problem with compressor lubricating oil? We sometimes lubricate our air line components, don't we?
I expect that the lubricating oil manufacturers would love to have lubricant formula for compressors that was Buna-N and seal-safe. I suspect that that nature of the environment inside the compressor requires the seal-aggressive additives to be in the lubricant to allow it to function properly, and the absence of those additives would prevent good lubrication of the compressor moving parts. That would allow damage to the compressor, a cost problem of greater magnitude.
The combination of water and the soup of contamination from the receiver, coupled with any contaminants in the main air lines (rust from the pipes / pipe dope, etc.) can send a slurry of crud down the air lines, possibly migrating through your air valves, to the actuators, or into your air tools.
When the equipment stops, and when the equipment cools, that crud dries out. It hardens into a varnish-like consistency that effectively slows or stops the operation of some of your control and actuator equipment. Next time you want to start the machine, some valves won't shift or actuators won't actuate.
Even if it's just straight water that's moving down the lines, that water tends to wash out factory lubrication in the various air line components, hastening their demise!
You can't stop your compressor from introducing gallons of water into the receiver. You can slow the compressor generated water from getting into your air lines. It is in your best interests to ensure that any water that does migrate to your lines from the receiver, gets taken out before it gets to air tools and other air driven equipment.