For a DN100 pipeline with the flow meter installed behind the control valve and a 5-m straight pipe section in front of the flow meter, is such an installation acceptable?
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This post was last edited by WindBlowsCool on 2012-6-21 at 17:37. As the title suggests: For a DN100 pipeline, the flow meter is installed after a control valve. After passing through three 90-degree bends, there is a straight pipe section that’s 5 meters long before the flow meter. Is this installation arrangement acceptable? Additional note: The medium is sulfur-containing wastewater; the pressure before the control valve is approximately 1.5 MPa. The flow meter is a orifice plate, which is used only for process control and not for measurement
For a flow meter of DN100, a straight pipe section of 5 meters is sufficient; any type of flow meter will work. Even according to the requirements for a straight pipe section 30D upstream, 5 meters of pipe is enough.
For a DN100 pipe, 5 meters of straight pipe section is sufficient.
As mentioned on the second floor, there is no problem with straight pipe sections; however, a few points still need to be taken into account: 1. The flow meter should be installed as close as possible in front of the control valve, to ensure that the medium fills the pipe completely and that the pressure difference remains stable, which helps achieve accurate measurements； 2. There are requirements regarding the direction of the pipeline at the flow meter’s outlet; the pipeline there cannot be directly vertical downward ； 3. The flow meter determines whether a reduction in diameter is necessary based on the existing process parameters; since you are involved in controlling this process, it is even more important to ensure accurate measurements.
I agree with the view above; there is a guideline of \"ten before and four after\" for the installation of flow meters, which requires a stable flow velocity in the straight pipe section.
The straight pipe length required for retrieving the flow meter, as well as the type of flow meter, can be found in the link below; it might be useful to you. http://bbs.hcbbs.com/thread-960062-1-1.html
No matter how many valves are present ahead, as long as the straight pipe section is sufficient, the flow will remain stable. The orifice ratio ranges from 0.3 to 0.6; there is no additional error for a 50D size. When the orifice ratio reaches 0.8, a straight pipe section of 80D is required to avoid any additional errors. If an additional error of 0.5 is allowed, then 40D is sufficient. Therefore, it is completely feasible for the original poster to install it in this way for control purposes.
I heard that it’s sufficient to know the specific diameter of the pipe, which is ten times for the first part and five times for the latter part.
There are also requirements for the straight pipe section behind the flow meter, and all of these need to be taken into account.
As mentioned on the 4th floor, it is best to install it on a horizontally running pipeline, after the pump outlet valve and before the control valve
I agree with the view from the 4th floor; it’s best to install the flow meter in front of the control valve. If you’re concerned about frequent maintenance of the flow meter, then simply add a bypass valve.