Orifice Union B16.36
Class 600 Weld Neck Orifice Flanges
B16.36 weld neck orifice flanges rated for Class 600 service
Class 600 Weld Neck Orifice Flanges are designed for high-pressure flow measurement applications in refining, petrochemical, and power generation facilities. The heavier flange body and larger bolt pattern provide the clamping force necessary to maintain a reliable seal at pressures up to the Class 600 rating envelope.
The increased flange thickness at Class 600 also provides deeper pressure tap holes with greater wall support around the NPT connections, reducing the risk of tap fatigue failure under pressure cycling. Orifice plate thickness must be selected to withstand the higher differential pressures encountered at elevated line pressures.
These flanges are commonly paired with ASTM A105 or A350 LF2 materials for carbon steel service, or ASTM A182 grades for stainless steel and alloy applications. Proper gasket selection becomes increasingly important at Class 600, with spiral wound gaskets featuring inner rings being the standard choice.
