Orifice Union B16.36
Class 900 Weld Neck Orifice Flanges
B16.36 weld neck orifice flanges rated for Class 900 service
Class 900 Weld Neck Orifice Flanges serve the most demanding flow measurement applications where line pressures require heavy-wall piping and high-integrity flanged joints. Available sizes are more limited than lower classes, typically ranging from NPS 1/2 through NPS 10, as larger orifice installations at these pressures are uncommon.
The substantial flange thickness and bolt loading at Class 900 provide excellent resistance to pressure-induced flange rotation, which is critical for maintaining orifice plate alignment and gasket seal integrity. Ring-type joint (RTJ) face configurations are available for the highest-integrity sealing requirements.
Applications include high-pressure gas transmission metering, supercritical steam measurement, and hydroprocessing unit flow control. Material selection at this pressure class often involves chrome-moly alloys such as F11 or F22 for elevated temperature hydrogen service.
