... 2.Acid and alkali resistant 3.High temperature resistant aluminum welding neck flange Welding Neck Flanges, Slip on Flanges, ... steel , carbon steel , nickel alloy ,cast iron ,brass , aluminum 3.class 150 300 600 900 1500 25004. pressure grade ... alkali-resistant to high temperature, the price reasonable calculation, beautiful appearance, texture performance is strong13.Processing methods: high precision ...