# How to choose the differential pressure value of orifice flowmeter

**Author:** **Source:** **Date:** 2021-06-01 14:20:45

How to choose the differential pressure value of the orifice flowmeter and what size orifice flowmeter should be used? "It is related to many factors such as uncertainty, straight pipe section, etc. Therefore, when calculating the aperture of orifice flowmeters and V-cone flowmeters, one cannot blindly choose a large pressure difference, but should comprehensively consider some related factors. Throttle device Manufacturers know that when a throttle device such as an orifice flowmeter calculates the orifice diameter according to field parameters, it will involve such a problem, that is, how to choose the maximum differential pressure value of the differential pressure transmitter? In our usual production process We can't blindly suggest our users to choose a large pressure difference value, and we are truly responsible to customers and enterprises.

1. When the pressure difference is large, the value becomes smaller, and the recommended minimum Reynolds number becomes smaller. In this way, the actual Reynolds number may be much larger than the recommended Reynolds number, so the flow coefficient tends to stabilize and the measurement accuracy is improved.

2. When the pressure difference is large, the minimum straight pipe section required can be shortened. In view of this feature, for orifice flowmeters, considering various economic factors, the opening value of the maximum pressure difference should be selected, and the opening value of the V-cone flowmeter is better, and when the field fluid is Newtonian fluid, V The straight pipe section of the cone flowmeter has low requirements, even if it is short, it does not exist.

3. For a differential pressure transmitter, the differential pressure is more stable than the differential pressure. The above basic introduction is the advantages of choosing a large differential pressure, but it will bring some shortcomings to a certain extent many times.

Anyone who is familiar with the processing technology of orifice flowmeters and V-cone flowmeters should know that when the pressure difference is too large, the direct result is that the opening is small, the relative pressure loss is also large, and the pressure loss of the orifice flowmeter is also very high. If this is added, the pressure loss of the entire process system will be quite large. ? The V flowmeter is slightly more moderate than the V cone flowmeter.

1. When the pressure difference is large, the value becomes smaller, and the recommended minimum Reynolds number becomes smaller. In this way, the actual Reynolds number may be much larger than the recommended Reynolds number, so the flow coefficient tends to stabilize and the measurement accuracy is improved.

2. When the pressure difference is large, the minimum straight pipe section required can be shortened. In view of this feature, for orifice flowmeters, considering various economic factors, the opening value of the maximum pressure difference should be selected, and the opening value of the V-cone flowmeter is better, and when the field fluid is Newtonian fluid, V The straight pipe section of the cone flowmeter has low requirements, even if it is short, it does not exist.

3. For a differential pressure transmitter, the differential pressure is more stable than the differential pressure. The above basic introduction is the advantages of choosing a large differential pressure, but it will bring some shortcomings to a certain extent many times.

Anyone who is familiar with the processing technology of orifice flowmeters and V-cone flowmeters should know that when the pressure difference is too large, the direct result is that the opening is small, the relative pressure loss is also large, and the pressure loss of the orifice flowmeter is also very high. If this is added, the pressure loss of the entire process system will be quite large. ? The V flowmeter is slightly more moderate than the V cone flowmeter.