Airco Argon Union Carbine Gas Regulator Valve Welding. These are great for someone who knows what they are doing with this valves. They may work, but the three are red taged and may need repaired. The one brass Airco will work. The item "Airco Argon Union Carbine Gas Regulator Valve Welding LOT of 4 (parts repair)" is in sale since Wednesday, March 1, 2017.This item is in the category "Business & Industrial\Hydraulics, Pneumatics, Pumps & Plumbing\Air Compressors & Blowers\Other Air Compressors". The seller is "crochrc" and is located in Bessemer, Michigan. This item can be shipped worldwide.