weld neck flange 18 Inch Class 1500 Posted on February 10, 2017July 1, 2017 weld neck flange 18 Inch Class 1500 Weld Neck Flange Class 1500 Size NPS : 18″ Size DN : 450 mm. Weight : 738 kg. StudBolt Size : 2 3/4″ UNC Or (M72) x 495 Long No. of Bolts : 16 EA. Holes Diamater : 73.025 mm. [wpfilebase tag=file id=2103 /] ansi b16 5 ansi flange dimensions ansi flanges asme b16 5 Class 1500 flange dimensions raised face flange Weld Neck Flange weld neck flange Class 1500