Van Stone Flange Raised 1/2 in Nominal Pipe Size Female NPT 3 1/2 in Flange Outside Diameter 9/16 in Flange Thickness Schedule 80 Class Class 150 For Pipe Schedule 80 PVC 150 psi Maximum Operating Pressure 140 Degrees F Number of Bolt Holes 4 2 3/8 in Bolt Circle Diameter 9/16 in Bolt Hole Diameter 1 1/16 in Overall Length Gray