Common Problems Experienced in Compressed Air Systems in Cold Weather

Posted on December 20th, 2019

Cold weather brings with it a particular set of challenges for compressed air systems and a number of problems can occur when temperatures drop below 41˚F (5˚C).

Here are some common problem areas to look out for:

Air Compressor Oil

If the temperature drops below 41°F (5°C), the viscosity of the compressor oil can increase.  Consequently, free movement of internal components is impeded resulting in higher electric loads and in extreme cases, the motor overheating.

Localized Freezing

Localized Freezing is an industry term referring to areas specifically vulnerable to icing or freezing.  Localized freezing can happen at several points in your compressed air system when temperatures drop below 34°F (1°C). At 32°F (0°C), water will freeze and any condensate in the system will begin to turn to ice. If moisture is not removed at the right point in the system, accumulated frozen condensate can cause serious issues.

Compressed Air Filters and Condensate Traps

Compressed Air Filters and Condensate Traps all have effluent drains to purge condensate water from the system. Effluent drain points can be particularly problematic because they are further away from the main air stream and are filled with water.  As a result, freezing can often occur more rapidly in these areas.

Refrigerated Air Dryers

Typically, Refrigerated Air Dryers will only lower the pressure dew point to 39˚F (4˚C). If the compressed air temperature drops below this temperature, condensation will still occur. In cold conditions, Refrigerated Compressed Air Dryers can freeze internally causing severe pressure drop or, in the worst cases, stopping air flow completely.

Desiccant Air Dryers

Localized Freezing problems can also occur with the use of Desiccant Air Dryers. Condensate can collect and freeze at any point where air is exhausted.

Valve Icing

Pneumatic Control Valves can operate slowly when the air is cold. Lubricants become more viscous and small orifices can quickly become blocked with ice.

External Compressed Air Lines

Even if the main compressed air system is indoors, pipes may extend outside of the heated space for some distance before re-entering another heated space. If condensate exists in the pipework it may freeze when exposed to a colder ambient temperature. This is particularly true if the pipework has low points where liquid may be able to collect.

 

Find out how to prevent and resolve localized freezing problems, and prepare your compressed air systems for winter, in Preparing Compressed Air Systems for Winter: Part 2.

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