Vapor Valve A valve in the vapor pathway of a vapor recovery system that opens to allow vapor to flow back to the storage tank and closes whenever product is not being dispensed. See also PEI/RP300. By rhys|2014-10-23T14:51:01+00:00October 23rd, 2014|Comments Off on Vapor Valve Share This Story, Choose Your Platform! FacebookTwitterRedditLinkedInWhatsAppTumblrPinterestVkXingEmail About the Author: rhys