DAE pressure equalization elements

Here's a description of pressure compensation elements for enclosures, as commonly used in industrial applications, control cabinets, and other protected housings, translated into American English.

Pressure Compensation Elements for Enclosures (Vents, Breathers)

What are Pressure Compensation Elements?

Pressure compensation elements, often called vent plugs, breather vents, pressure equalizing valves, or membrane vents, are components designed to equalize the pressure difference between the inside of a sealed enclosure and its surrounding environment. They are engineered to allow air and water vapor to pass through while repelling liquid water and particles. This is typically achieved using a special, microporous membrane, often made from materials like PTFE (Polytetrafluoroethylene).

Why are They Important? The Problems Without Pressure Compensation:

In sealed enclosures, especially those used outdoors or in environments with significant temperature fluctuations, various issues can arise without proper pressure equalization:

1. Vacuum Effect / Negative Pressure: When the temperature inside the enclosure drops (e.g., at night or during a sudden cold snap), the air inside contracts. This creates negative pressure within the enclosure, which can:

   • Suck in Gaskets: Weaker seals can be pulled inward, compromising the IP (Ingress Protection) rating and leading to leaks.

   • Draw Moisture Through Seals: Negative pressure can cause humid air or even liquid water to be drawn in through tiny imperfections in the gaskets or cable glands.

2. Overpressure / Positive Pressure: When the temperature inside the enclosure rises (e.g., due to sunlight or heat dissipation from internal components), the air expands. This creates positive pressure. Without a way to escape, this overpressure can:

   • Push Gaskets Outward: The seals are stressed and can wear out prematurely or become ineffective.

   • Deform Enclosures: In extreme cases, thin-walled enclosures might slightly deform.

3. Condensation: This is the biggest and most common problem. Moisture enters the enclosure through the pressure cycles described above. When the internal temperature drops and the saturated air cools, the water vapor condenses into liquid water. This condensation can:

   • Cause Corrosion: On metal parts, screws, and circuit boards.

   • Trigger Short Circuits: On electronic boards.

   • Lead to Malfunctions: By impairing sensitive components.

How Pressure Compensation Elements Work:

Pressure compensation elements operate based on the diffusion of gases and vapors through a semi-permeable membrane. The membrane is structured so that its pores are small enough to repel water droplets and dust particles (due to capillary action) but large enough to allow air molecules and water vapor to diffuse. This enables continuous pressure equalization and the removal of moisture in vapor form.

Benefits of Using Pressure Compensation Elements:

• Prevents Condensation Buildup: This is the primary benefit, significantly reducing moisture-related failures.

• Maintains IP Protection: By equalizing pressure, seals are relieved of stress, ensuring their integrity over the enclosure's lifespan.

• Extends Component Lifespan: Electronics and other components are protected from corrosion and moisture damage.

• Reduces Maintenance and Downtime: Fewer moisture-related defects mean fewer repairs and less costly downtime.

• Improved Operational Reliability: Ensures more consistent performance of the system.

• Low Cost: Compared to the potential damage that moisture can cause, pressure compensation elements are a very cost-effective solution.

Applications:

Pressure compensation elements are used in a wide range of enclosures, including:

• Control Cabinets and Distribution Boxes (especially outdoors)

• Photovoltaic Inverters and Junction Boxes

• LED Lighting (Outdoor Luminaires)

• Sensors and Measurement Devices (outdoor use)

• Telecommunications Equipment

• Cameras and Surveillance Systems

• Automotive Applications

• Marine and Saltwater Applications (often with special salt-spray resistant membranes)

Installation:

Pressure compensation elements are typically screwed into a drilled hole in the enclosure. The membrane is positioned to allow for defined air and moisture exchange. Correct positioning (often in the upper part of the enclosure to exchange the driest air possible) and proper sizing (number and size of elements based on enclosure volume and temperature fluctuations) are crucial for optimal function.