When air is compressed, it is heated to a point that causes the water or moisture to turn to vapor. As the air begins to cool, the vapors turn to condensation, which can cause performance issues in a compressed air system. Many times this condensation forms in the basic components in the system like a receiver tank, dryer or filter.
It’s important to remove this condensation from the system before it causes any issues. There are four basic types of condensate drains that can be used to limit or prevent loss of air in the system.
The first method would be to have an operator manually drain the condensation through a drain port or valve. This is the least reliable method though as now it’s the operator’s responsibility to make sure they close the valve so the system doesn’t allow any air to escape which can lead to pressure drops and poor end-use device performance.
Secondly, a float or inverted bucket trap system can be used in plants with regular monitoring and maintenance programs in place to ensure proper performance.. These types of drain traps typically require a higher level of maintenance and have the potential to lose air if not operating properly.
An electrically actuated drain valve can be used to automatically drain the condensate at a preset time or interval. Typically these incorporate a solenoid valve or motorized ball valve with some type of timing control. These types of systems can be unreliable though as the valve may open without any moisture being present in the line, which can result in air loss or it may not be actuated open long enough for acceptable drain off. With these types of drains, it’s best to use some type of strainer to remove any particulate that could cause adverse performance.
Lastly, zero air-loss traps utilize a reservoir and a float or level sensor to drain the condensate and maintain a satisfactory level. This type of setup is very reliable but does require the reservoir be drained frequently to keep the system clean and free of debris or contaminants.
If you have any questions or would like to discuss a particular process, contact an application engineer for assistance.
Float drain image courtesy of the Compressed Air Challenge