Custom Pressure/Vacuum Relief Vents provide protection from excessive pressure buildup and from potential collapse caused by a vacuum condition forming in their installed applications. These valves are designed to exchange air between the interior of the reservoir and the outside atmosphere. As a made-to-order custom, relief settings and valve body configurations are designed and manufactured to meet the requirements of each application. Most Common Customized Options Body material: Aluminum, brass, plated carbon steel, stainless steel Seal material (when applicable) selected based on performance requirements Pressure relief range Vacuum relief range Filtration level of incoming and/or exhausted air Defined pressue drops at given flow rates of exhausted air Manual, push button valve opening to relieve pressure in reservoir prior to servicing (For reservoirs that normally operate under positive pressure) Adapter connections JIC per SAE J514 O-ring Face Seal per SAE J1453 Straight thread o-ring stud per SAE J1926 or ISO 8434 Male or female pipe threads (NPTF, PTF, BSPP, BSPT) Surface treatments: Zinc Trivalent Chrome (clear), Zinc Yellow Dichromate, Anodized, Natural Product markings (i.e. part numbers, date codes, relief settings, etc.)