Boiler Repairs: Leaking Air Separator

A leaking air separator in a boiler can create operational issues for your boiler. The first principle behind the separation of air in the boiler is reduction of water velocity. This reduction helps the boiler run more efficiently by removing air from the boiler water. Free air that collects at the top of the boiler is prevented from being circulated out into the system and into radiation through the use of boiler dip tubes. Dip tubes tend to be standard equipment by most boiler manufacturers.

Types of Air Separators

The air separator is a piece of equipment that is used to separate the free air from system water. The two types of air separators available are the IAF and IAS type air separators. The IAF type air separator is available with different nozzle sizes. The IAS type is available with connections of 1-inch up to 4-inch pipe. The problem of an air separator that leaks can be as simple as a mismatched pipe connection at the point that the air selection takes place. The repair would simply involve resizing the pipe for its proper connection in order to eliminate the leak.   

Leaks in a Centrifugal Force Air Separator

A second principle behind the use of an air separator is that of the use of centrifugal force. A tangential nozzle is used in order to create a vortex at the center of the boiler. This is done since air is less dense than water. This centrifugal force causes a whirlpool in what is an air collector screen and sent upward. The air goes to the compression tank in the air control system or goes through a vent and is expelled in the atmosphere. This takes place in an air elimination system.

In the case of an air separator that leaks, creating a loss of the necessary centrifugal force to expel compressed air inside the boiler, all connections need to be checked to determine the source of the leak. This diagnostic test may result in the replacement of the air separator device or some similar repair in order to reestablish the connection and return the boiler to its efficient operation.   

Leaks in a Coalescence Air Separator

Another principle in the use of a boiler air separator is the principle of coalescence. Coalescence happens through the use of stainless steel wires that attract small bubbles on the surface of the wires. As the bubbles combine they form large bubbles that  are separated from the boiler water. Leaking that takes place in a boiler that uses the principle of coalescence can be caused by damaged wires that are placed in the boiler to create the coalescing condition. Replacement of any or all of these wires is the repair needed to correct this problem and facilitate the separation of air from the boiler.

You may be able to perform the repairs necessary to abate a leaking air separator. This requires you to understand the principle that is being used in separating air within your boiler, be it the principle of water velocity, centrifugal force or coalescence.