GORE^® Protective Vents Improve Durability of Base Stations By Equalizing Pressure

PureWave Networks, Inc., of Santa Clara, California, develops advanced, LTE small cells and compact WiMAX base stations that have revolutionized the economics of 4G network deployment and operations. The PureWave Quantum™ family of base stations offers advanced performance in a rugged unit that can be mounted virtually anywhere outside, eliminating the need for separate remote radio heads. These products deliver the coverage of a macro base station or can be deployed as 4G small cells in a dense urban environment.

Unlike the typical split-unit design, the PureWave Quantum™ contains all of the electronics inside a single cast-aluminum housing with a closed cell gasket. These units were designed for outdoor installations worldwide, so they needed to withstand extreme variability in temperatures and weather conditions. In addition, they needed to meet the IEC standard for full immersion (IP67) required for military and oil/gas applications. The PureWave Quantum™ engineering team designed a rugged housing with 26 perimeter screws to ensure a solid seal. However, they knew that they needed to account for increased pressure caused by heat buildup during operation of the internal electronics. Leaving a small hole in the housing wall would equalize pressure, but it would also provide easy access for contaminants such as rain, dirt, dust and even insects. Combining the pressure from heat buildup with pressure caused by sudden changes in external temperatures can result in internal pressure differentials as much as three pounds/inch² (3 psi). Over time, these pressure differentials put stress on the housing seals, which can cause the seals to fail and draw in moisture vapor. If the moisture vapor has no path out of the housing, it can condense and corrode the sensitive electronic instrumentation that is being protected. Specifications that result in differentials of 3 psi have a direct effect on total costs because they require tighter tolerances, which in turn increase complexity of product design and manufacturing.

The PureWave Quantum™ engineering team incorporated a GORE^® Protective Vent in the design of the device housing. Based on the size and volume of the housing, the team selected an adhesive vent that they mounted near the top of the side wall to gain maximum airflow. Rated to meet ingress protection up to IP67, this vent equalizes pressure within the housing by allowing air and moisture vapor to pass in and out of the enclosure freely, reducing the potential for condensation. At the same time, the vent serves as a barrier to prevent liquid, dirt, dust, salt and other contaminants from entering.

According to Brett Catterall, Director of Operations at PureWave, “We expect our product to perform reliably for at least ten years, regardless of whether they are installed in the mountains of Northern Canada or the deserts of Asia. With these widely varying environments, we knew we needed to design a housing that provided protection but also could breathe. GORE^® Protective Vents have proven that they maintain equalized pressure during rapid thermal/pressure changes. Thousands of our systems have been installed in some of the most rugged environments for more than four years, and we have experienced no leakage issues. This level of durable performance is why we continue to turn to Gore when developing all of our products.”