Upstream and Downstream Flow Straight Pipe Requirements refer to the length of straight pipe before and after the installation location of the flowmeter.
In order to ensure that the fluid flow state is uniform in the pipeline, the flow field of the fluid can generally be stabilized. It is required that the straight pipe section before and after the installation position of the flowmeter should be long enough. Otherwise, it will cause inaccurate measurement.
The general rule of thumb for straight piping is a five-diameter length of piping upstream and three diameters downstream from the meter (measured from the center of the tube).
Next, we will detail the various flow meters Upstream and Downstream Flow Straight Pipe Requirements.
what is upstream and downstream flow?
For pipelines where fluid flows, we must first understand the upstream and downstream fluids when installing the flowmeter.
The direction of fluid entry is upstream. The direction of fluid discharge is downstream.
The straight pipe section of the flowmeter is the straight pipe section that requires a certain length of the water inlet and outlet of the flowmeter. That is, the pipe in that section needs to be straight. There can be no elbows, valves and the like. Generally, the upstream length requirement will be longer than the downstream length requirement.
10D Upstream and 5D Downstream
When users use the orifice flowmeter, they generally require 10D Upstream and 5D Downstream for the straight pipe sections before and after the orifice flowmeter. So what does this D stand for? Today I will briefly talk about it.
The D represents the diameter of the pipe. For the orifice plate in the orifice plate flowmeter, the minimum requirements for the front and rear straight pipe sections are 10D Upstream and 5D Downstream. If there is a pump or regulating valve in front of the orifice plate, then the requirements for the straight pipe section are greater.
Different Flow Meter Installation Rule of Thumb
There are many professional organizations that provide guidance and standards for most flow techniques used. Some of them are ISA, ISO, API, AGA, ASME and ANSI.
When in doubt, it is recommended that you refer to these guides. As they have been tested and provide a good starting point for ensuring that the flowmeter is performing properly.
Some very common guidelines/standards are listed below:
Coriolis – ISO10790
Critical Nozzle – ISO9300
Differential Pressure – ISO5167
Electromagnetic – ISO6817
Positive Displacement – ISO2714
Thermal Mass – ISO14511
Turbine – ISO2715
Ultrasonic – ISO17089
Variable Area – ISO11605
Vortex – ISO/TR12764
These are some general guidelines to consider when determining the right flowmeter placement for your application. By asking the right questions and having a good understanding of existing guidelines and standards, you should be able to take advantage of a very large investment in flow meters.
Sino-Inst offers over 50 flow meter for flow measurement. About 50% of these are differential pressure flow meters, 40% is the liquid flow sensor, and 20% are Ultrasonic Level Transmitter and mass flow meter.
A wide variety of flow meters options are available to you, such as free samples, paid samples.
If you have any questiones about Upstream and Downstream Flow Straight Pipe Requirements-for Flowmeter Installation, please contact us!
Sino-Instrument is a globally recognized supplier and manufacturer of flow measurement instrumentation, located in China.
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