The location and installation of primary flow elements such as the orifice plate or flow nozzle can be as important in accurate flow measurement as the element itself. Piping arrangements which include flow disturbing fittings such as elbows or valves, can affect the accuracy of flow measurement for several diameters preceding, and to a lesser extent, following the primary flow element. The internal roundness and surface roughness 01 the pipe immediately preceding and following the primary element can also affect accuracy. To insure accurate flow measurement, the fluid should enter the primary element with a fully developed velocity profile free from swirls and vortices. To achieve such a condition it is necessary to have adequate lengths of straight pipe both preceding and following the primary element. As a manufacturer of primary flow elements, Tech Tube offers complete fabrication and design of precision orifice and nozzle meter tubes in a wide variety of configurations. All meter tubes are designed and manufactured to meet or exceed the recommendations of the AGA and ASME where applicable.