Weld Neck Flange Flat Face 1/2 in Nominal Pipe Size Flanged x Weld Neck 3 1/2 in Flange Outside Diameter 3/8 in Flange Thickness 3 1/2 in Overall Length Aluminum Class Class 125 For Pipe Schedule 40 125 psi Maximum Operating Pressure 185 psi Max Steam Pressure 0 Degrees to 270 Degrees F Number of Bolt Holes 4 1/2 in Bolt Hole Diameter