Chemtech Alloys Pvt. Ltd manufactures Flange. Chemtech Alloys Pvt. Ltd is an ISO 9001:2000 certified company. Flange in available with Stainless steel, carbon steel and Alloy steel finish. Technical Specifications of Flange are: Size: 1/8 inch NB TO 48 inch NB Class: 150#, 300#, 400#, 600#, 900#, 1500# & 2500#.