DE2925139

An orifice fitting mechanism for pipeline flow measurement systems includes a fabricated body structure that is so fabricated that internal and external body plate connection welds may be effectively utilized in order that the body structure will have sufficient structural integrity to withstand the forces of high pressure service. Internal and external welding of the body plates is enhanced through the provision of internal hub rings that define portions of the internal through conduit structure of the body and also define a properly oriented transverse opening that effectively receives an orifice plate carrier assembly in sealed relation therein. The hub rings also provide for close positioning of pressure tap passages as desired for accurate flow measurement. A replaceable valve support mechanism is employed allowing the slide valve system of the orifice fitting to be field replaceable without requiring replacement of either of the upper or lower body sections.