Electric Industry Pro

Flow element used to create a pressure change by accelerating a fluid stream is the venturi tube (Here Differential Pressure based flow meter i.e.Venturi tube is taken as an example for discussion): a pipe purposefully narrowed to create a region of low pressure. As discussed previously , venturi tubes are not the only structure capable of producing a flow-dependent pressure drop. You should keep this in mind as we proceed to derive equations relating flow rate with pressure change: although the venturi tube is the canonical form, the exact same mathematical relationship applies to all flow elements generating a pressure drop by accelerating fluid, including orifice plates, flow nozzles, V-cones, segmental wedges, pipe elbows, pitot tubes, etc. If the fluid going through the venturi tube is a liquid under relatively low pressure, we may vividly show the pressure at different points in the tube by means of piezometers (Think of a piezometer tube as nothing more than a manometer tube: th...