Overview

The 3500B, 3600B Series Vacuum Relief Valves are designed to protect atmospheric and low pressure tanks from excessive vacuum while the 3650B Series protects from excess pressure or vacuum. The 3500B, 3600B and 3650B Series are weight loaded which utilizes weights proportional to the seat surface area to achieve the desired setting. Flow curves are provided to help you select the proper size for your vacuum or pressure venting requirements. Additionally, an “All Weather” option is available for freezing climates in the way of 3501B, 3601B & 3651B Series.