Orifice Union B16.36
Class 300 Weld Neck Orifice Flanges
B16.36 weld neck orifice flanges rated for Class 300 service
Class 300 Weld Neck Orifice Flanges per ASME B16.36 are the most commonly specified orifice flange configuration for medium-pressure process piping. The weld neck design provides a tapered hub that reduces turbulence near the orifice plate, improving measurement accuracy. These flanges feature two 1-inch NPT pressure tap connections positioned 180 degrees apart on the flange face.
The raised face dimensions, bolt circle, and bolt hole patterns for Class 300 weld neck orifice flanges match standard B16.5 Class 300 weld neck flanges, ensuring compatibility with existing piping layouts. Available sizes typically range from NPS 1 through NPS 16, covering the majority of process flow measurement applications.
Installation requires precise alignment of the pressure taps relative to the orifice plate bore. The flange pair is bolted together with the orifice plate sandwiched between the raised faces, and jack screws in the flange rim allow for separation during plate inspection or replacement without disturbing the piping.
