... alkali resistant 3.High temperature resistant ansi b16.5 class 1500 weld neck flange Welding Neck Flanges, Slip on Flanges, ... ,cast iron ,brass , aluminum 3.class 150 300 600 900 1500 25004. pressure grade:PN2.5 PN 6 PN10 PN16 PN25 ... (1200NB) in 150 LBS, 300 LBS, 600 LBS, 900 LBS, 1500 LBS, 2500 LBS ASA 150, ASA 300, PN 2.5 ... as per user's special requirements ansi b16.5 class 1500 weld neck flange