4AN Line Purge Valve Kit: Designed to help release the trapped air or gaseous nitrous from the feed lines. Release Trapped Air / Gaseous Nitrous: The primary purpose of a purge valve is to release trapped air or gaseous nitrous from feed lines, so to help ensure consistent performances. Ultra Durability: This 4AN Line Purge Valve Kit is made of premium copper, steel and rubber, which is sturdy and durable. For high strength, corrosion & rust rsistance, stable performance, and long service life. Direct Replacement: .
