Description Relief valve protects system and cows in case of regulator failure. Relief Valve for Sentinel Controllers models M350 and M500 and similar sized large volume controllers Mounts 3 inch NPT protects against occurrences of high vacuum. For systems with CFM's over 250, two are recommended. Set at 1 inch above your operating vacuum level. GEA # 4999-1082-231 Ezee 67311 9/26
