Flange annular orifice plate flow meter

Annular Orifice Plates are the simplest type of primary flow element. Their bore diameter is calculated to generate the specified differential pressure at full-scale flow rate. Suitable orifice plates are available for a wide range of different media.

Characteristics and Application:

Suitable for measuring steam, gas, cooling water and other dirty media. The special structure of the Annular Orifice Plate "periphery circulation, blocking in the middle" makes impurities unimpeded and condensate water formed by steam when steam stops flowing away in time, thus improving the working reliability and measurement accuracy.

Not only it can measure the flow of general fluid, but also it can be used for fluid containing various impurities (such as dust, suspension, precipitation, etc.) , such as all kinds of gas hot air, flue gas, natural gas, circulating cooling water,etc. When measuring saturated steam and superheated steam, it can avoid the accumulation of condensate water formed when stopping the supply of steam. And once the steam is supplied again, it can quickly enter the accurate measurement state.

The instrument body has a straight measuring tube, and a coaxial round plate is fixed in the middle of the measuring tube. The round plate is fixed to the pipe by a support frame, which is suitable for measuring various fluid media. In field installation, installation errors (such as off-center, sealing gaskets stuck in the pipe) have little effect on the measurement of the meter. More reliable and accurate in measurement than segment orifice plate, eccentric orifice plate. 

Welded connection, suitable for high temperature, high pressure fluid (such as hot steam) flow measurement. When the annular Orifice Plate measures the high temperature fluid, the periphery of the flow measuring plate is a free state, and the temperature expansion only changes the contour size, does not change the edge sharpness and shape, so it does not change the outflow coefficient, does not affect the measurement accuracy.When measuring high pressure fluid, because the measuring  flow plate is in the pipeline, and has nothing to do with the static pressure level, which reduces the processing cost.

Annular orifice plate has the same characteristics of simple structure, firmness, easy installation and use as Standard Orifice Plate, while without long straight pipes, has the advantage of working in poor pipeline conditions.

The "pressure balancing ring" structure is adopted. When the straight pipe section is not long enough, it can still be accurately measured. For example, in the downstream of a 90° elbow, a 2D straight pipe section before the meter is enough; if  in the downstream of a 30° elbow, a 0.5D length straight pipe section is ok before the meter. 

Adopting clamp cover and heat preservation structure, suitable for fluid that is easy to crystallize, easy to vaporize and other needs to heat or cool (such as liquid ammonia, some chemical products, etc.).

Adopting a differential pressure transmitter with a remote transmission sylphon can measure the flow of dirty media such as residual oil and heavy oil.

Application of the orifice plate, flange and annular chamber

Power generation

Oil production and refining

Water treatment and distribution

Gas processing and transmission

Chemical and petrochemical industry

Special features of the orifice plate, flange and annular chamber

Max. operating temperature and pressure limited by material and flange

Suitable for liquid, gas and steam flow measurement

Accuracy ≤ ±0.5 % of actual flow rate

Measurement repeatability :0.1 %