311U-12 Finish: Galvanized, Diameter: 0.5" Features: -Joint union. -Brass inserted seat. -Unions are made of high grade malleable iron with a brass to iron seat. -Brass seat ring is pressed into a recess in the body end of the union under heavy pressure making the brass an integral part of the iron union. -For steam working pressure up to 150 lbs. -Octagon Nut. -For non-shock cold water, oil and gas to 300 lbs. -All fittings are pressure tested, 150 PSI. -Zinc coating is applied by hot dip process. -Diameter: 0.13" - 2".