An orifice is simply a flat piece of metal with a specific-sized hole bored in it.

Orifice flow meters are the most popular liquid flow meters in use today. The secondary element measures the differential pressure and provides the signal or read-out that is converted to the actual flow value.

And, the measurement accuracy of the element must be good over a reasonable range. The unit must be properly matched to the pipe size, flow conditions, and the liquid’s properties. The primary element causes a change in kinetic energy, which creates the differential pressure in the pipe. The flow rate is obtained by measuring the pressure differential and extracting the square root.ĭifferential pressure flow meters, like most flow meters, have a primary and secondary element. The basic operating principle of differential pressure flow meters is based on the premise that the pressure drop across the meter is proportional to the square of the flow rate. Estimates are that over 50 percent of all liquid flow measurement applications use this type of unit. These meters, which boast high accuracy, calculate fluid flow by reading pressure loss across a pipe restriction. Differential pressure flow meters are, by far, the most common units in use today. The use of differential pressure as an inferred measurement of a liquid’s rate of flow is well known. Those “inexpensive” purchases can be the costliest installations.įlow Meter Types and Uses Differential Pressure Flow Meters One of the most common flow measurement mistakes is the reversal of this sequence: instead of selecting a sensor which will perform properly, an attempt is made to justify the use of a device because it is less expensive. It is also recommended that the cost of the installation be computed only after taking these steps. When choosing a flow meter to buy, one should consider such intangible factors as familiarity of plant personnel, their experience with c and maintenance, spare parts availability, and meant time between failure history, etc., at the particular plant site. Since flow control is often essential, measuring the flow of liquids and gasses is a critical need for many industrial applications – and there are many different types of flow meters that can be utilized depending on the nature of the application. A flow meter (or a flow sensor) is an flow instrument that is used to indicate the amount of liquid, gas, or vapor moving through a pipe or conduit by measuring linear, non-linear, mass, or volumetric flow rates.

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