Pressure transmitters measure flow rate

Provide complete data before making a selection. There’s no way to answer your question

When using differential pressure to measure flow rate, it is necessary to accurately calculate the range of differential pressure generated by the throttling element; without such data for calculation, it’s nothing but nonsense.

The differential pressure of a flow meter (standard orifice plate) is generally in the range of 16–100 KPa; select a value based on the common integer range of the transmitter. The selection criterion is that the β value of the orifice plate at that differential pressure lies within the recommended range (with the Reynolds number of the measuring element within an appropriate range). Theoretically, the measuring element is manufactured based on a differential pressure value specified in advance by humans. But in reality, when the calculation results are not satisfactory, it is necessary to specify a different differential pressure value. Therefore, the range of the transmitter is usually specified by designers based on experience, taking into account factors such as the medium, pipe diameter, throttling element, required accuracy, required straight pipe section length, and allowable pressure loss. Using a larger pressure difference can, in most cases (though it’s not always the case), improve measurement accuracy, expand the effective range of the throttling element, and reduce the length of the straight pipe section. It also increases the pipeline pressure loss. Therefore, the simplest way to choose the transmitter range is to let the manufacturer of the throttling element make the recommendation.

1. When the differential pressure is high, the β value decreases, and a lower minimum Reynolds number is recommended for use. As a result, the actual Reynolds number can be much higher than the recommended value; this causes the flow coefficient to stabilize, thereby improving the measurement accuracy. 2. When the differential pressure is high, the required minimum straight pipe section can be shorter. 3. For differential pressure transmitters, those with a larger differential pressure are more stable than those with a smaller one. 4. When the differential pressure chosen is too high, the direct consequence is that the orifice size becomes very small; as a result, the pressure loss is also high. Flow meters using orifices already experience significant pressure losses, and if this factor is added on top of that, the costs incurred for the entire process system due to such pressure losses can be quite substantial.

No flanges are needed; the pressure pipe can be connected directly

It’s a double-flange type, and it’s also a low-precision instrument. The accuracy is terrible, like dog shit. :lol

Based on your question, it’s probably not related to the instrumentation field, right? The 3rd floor has already replied. One more thing: for measuring flow rate using the differential pressure method, the differential pressure gauge is selected based on the type of measuring element. For example, the common wedge-type differential pressure transmitter with double flanges, and the orifice plate combined with a regular differential pressure transmitter

A standalone differential pressure is not useful; a corresponding throttling element is needed to calculate the differential pressure value

For differential pressure types, it is necessary to calculate the differential pressure value, and then select a transmitter with an appropriate range based on that value. The type of flange to use depends on your requirements; if the medium is dirty or corrosive, double flanges and similar types are generally not used

The range needs to be calculated; those with double flanges are wedge flow meters, while if flanges are not used, an orifice plate must be installed