Nitrous Oxide System - NOS Nitrous Purge Valve Kit -4 AN Line [Black Finish] (16030BNOS)Purge Valve Kit NOTE: The lower the ambient temperature, the lower the resultant bottle pressure is leading to a potential fuel rich condition. Although usually not harmful to the engine, loss of optimal power can occur. On the other hand, very high ambient temperatures can lead to leaner burning conditions and loss of optimal performance as well as possible damage to engine components! NOS Nitrous System Purge Valve Kits are designed to release gas