Schedule 40 Socket Weld Flange Raised Face 4 in Nominal Pipe Size Flanged x Socket Weld 9 in Flange Outside Diameter 15/16 in Flange Thickness 1 5/16 in Overall Length Stainless Steel 304/304L Class Class 150 275 psi Maximum Operating Pressure 150 psi Max Steam Pressure Number of Bolt Holes 8 8 1/2 in Bolt Circle Diameter 3/4 in Bolt Hole Diameter