ME664

MEC vapor equalizing valves can be purchased in single or double check versions. The single check version can be used to facilitate pressure equalization of lines or containers but must not be installed directly into the container. A properly sized excess flow device must first be installed into container openings for compliance with NFPA Pamphlet #58. Double check versions consist of both an upper and lower check assembly. The upper check can be opened with vapor equalizing hose couplings equipped with projecting nozzle tips where the lower check is a normally open excess flow type. The lower excessflow check assembly automatically closes when flow out of the container exceeds its rated capacity. MEC double check vapor equalizing valves feature a two piece body construction where the upper check can be repaired while in service with minimal leakage from the container.