UKL piston valves are ideally recommended for critical and hazardous media, including Steam, Heat Transfer Oils, Acids, Gases, VACUUM.Manufactured in Forged Carbon Steel Stainless Steels to 800# – Sizes 15mm to 40mm, in SW and Threaded Ends. Cast Carbon Steel Stainless Steels with Flanges to 150#, #300 & DIN standards 50 to 200mm.