
Enclosure Pressure Compensation

Hazardous location enclosures are specifically designed to isolate electrical components from hazardous locations. Hazardous locations are classified as areas where there is the possibility of explosion or fire because of the presence of ignitable or combustible gases, vapors, liquids, fibers or dust. Electrical equipment can be a potential source of ignition through sparks, equipment failure and high temperatures. Hazardous location enclosures are constructed to eliminate the potential for ignition of the atmosphere.
Temperature fluctuations in an enclosure in relation to the environment, produced by the installed heat generating components and the changes in the ambient temperature, result in changing pressure conditions. These pressure changes can lead to the penetration of humidity and dust into the enclosure. Installing a pressure compensation device can compensate for these pressure fluctuations.
Hoffman Pressure Compensation devices provide IP66 protection in corrosive applications requiring slow pressure equalization. Pressure differentials in a tightly sealed enclosure result from heat generated by electrical equipment within the enclosure and fluctuations in outside ambient temperature.
Products
3 common reasons to use purge systems
- They allow electrical enclosures to be installed in hazardous areas without the need for explosion proof enclosures.
- They recycle the air inside of an enclosure, reducing the internal temperature.
- They help reduce the effects of corrosion on components housed within the enclosure.
How does a purge system work?
Purge systems use incoming air from a supply line, solenoid valves, pressure gauges and pumps, to constantly maintain a positive pressure inside an enclosure. This prevents any flammable gases from entering the enclosure potentially causing an ignition event to occur. By maintaining a positive pressure within the enclosure, moisture and corrosive gases are also prevented from entering the enclosure and damaging components. Most purge systems will ensure that the air inside the enclosure is recycled a certain amount of times within a given time period. This air recycle function assists in maintaining a cooler temperature within the enclosure.