Description : Blowoff valve SQV polished is available as a universal unit for custom applications, kits come complete with all needed mounting flanges, brackets, and miscellaneous hardware for a bolt-on installation. The SQV is a dual stage pull type relief valve. Unlike other blow off valves that are push type, the SQV will not leak under high boost conditions nor under vacuum at idle. Being of a pull type valve structure, the SQV can not physically leak under any level of boost because boost pressure also keeps the valve closed against its seat. The SQV is actuated by pressure alterations only, not by the rate of pressure or vacuum in the line, which ensures a quick valve response and complete closure during idle.