Orifice flanges are supplied as which type of fitting?

Orifice flanges are specifically designed to facilitate the measurement of flow rates in pipelines and are indeed supplied as raised face weld neck flanges with flange taps. This design ensures that the orifice plate can be sandwiched between two of these flanges, allowing for easy installation and maintenance. The raised face provides a greater surface area for a better seal, which is essential in preventing leaks while measuring the flow of fluids.

The inclusion of flange taps allows for the connection of pressure measurement devices, which are necessary for calculating flow rates based on differential pressure across the orifice. This is a crucial aspect of orifice flanges, as these fittings need to provide not only structural support but also meet the specific requirements of flow measurement applications within piping systems.

In contrast, other types of fittings mentioned do not possess the unique characteristics required for orifice applications. For example, socket weld fittings are used for connecting pipes and are not compatible with flow measurement needs. Blind flanges serve to close off a piping system but do not have the necessary provisions for orifice plates and associated instrumentation. Flat face flanges, while useful in some general applications, do not provide the necessary sealing and pressure measurement features demanded by orifice plate systems.