Factors that could affect accurate flow meter measurement, but not limited to impurities, pressure, water volume and bubbles. To avoid this, Lorric recommends to carefully choose a suitable installation location. Please see below for a simple guideline on how to correctly install a flowmeter either vertically or horizontally. Through Lorric’s decades of on-site experience, we will provide recommendations to increase the accuracy of your flowmeter.
Stable flow field makes best accuracy of flow measurement.
The initial flow will be a mixture of dual flow directions which inevitably leads to unstable flow speeds. At this point, measuring flowrate is unpredictable and difficult. Needless to say, inaccurate. However, accurate flow measurement is attainable with a fully developed and stabilized flow.
Tips for installing a paddlewheel flowmeter correctly.
1. There should be at least 10D (10x the inside diameter of the pipe) of straight pipe in front of the flowmeter and 5D of straight pipe behind the flowmeter to stabilize flow.
During flow movement, where the liquid is coming from means the front and where it’s moving to means the back. Generally, it is recommended that the flowmeter be installed at a position 10D (10x inside diameter of the pipe) at the front and 5D at the back (as shown in the figure below). If the inside of the pipe diameter is unknown, the outside of the diameter can be used.
2. Install the paddlewheel flowmeter before the valve.
The flow meter should be installed upstream of valve, so the fluid will be fully developed. This recommendation is also applicable to other piping components that may affect the flow field.
3. Filters Installed Before and After the Flow Meter
For longer service life and better measurement accuracy for the paddlewheel flow meter, we suggest setting filters or related technology before or after the flowmeter. The filter installed before the flow meter can filter impurities or foreign objects from sticking on the blades that make it unable to rotate. The filter installed after the flowmeter can prevent downstream equipment (ex: pump) from being damaged by any falling parts. Lorric’s paddlewheel flow meter equipped with patented AxleSense technology, can detect paddle disappearance by displaying a warning signal (flashing bright red light) on the operational screen.
LORRIC paddle wheel flow meter equipped with the patented axlesense design, when paddle disappears, it can detect give the corresponding warning, so the better field management can be realized.
*DISCLAIMER: Please be aware that magnetic fields or residual magnetism may cause interference to the flowmeter which may result in damage if they are used near the installation site. The purchaser must determine the applicability of the product for its desired use and assumes all risks in connection therewith. LORRIC assumes no responsibility or liability for any omissions or errors in connection with the use of its products. The alarm used to detect paddle damage or loss is intended to assist on-site operators to find out what is causing equipment abnormalities. Because there are a myriad of variables involved with on-site operation and magnetic fields that come from other equipment, the alarm function is liable to fail. Please do not take the alarm function as a single source for monitoring your flow system. Please contact LORRIC for advanced help.
Please note: If the flow field has high levels of instability, a straight pipe with 20D (20x the inside of diameter of the pipe) may be required, or a rectifier may be installed in the pipe. This will give the fluid more time to fully develop.
4. Install paddle wheel flowmeter at the pipe which is inclined with horizontal pipe for 45°or 135°.
If the paddlewheel flowmeter is installed on top of the high place of the pipeline where air bubbles might form. The air bubbles could get stuck between the paddles which makes it difficult to measure. Also, if the flowmeter is installed right below the pipeline impurities and precipitation could get stuck between the paddles. This could make it difficult to rotate the paddles. In addition, installing at the right side of the pipeline is not recommended. It may cause wear-and-tear caused by high speeds to the ceramic part of the paddle. We highly recommend installing the paddle wheel flowmeter inclined at 45°or 135°on a horizontal pipe. It is the ideal location for accurate measurement.
5. Install paddle wheel flowmeter at the location where the pipe is filled with liquid. The most recommended location is the lower place of concave pipeline.
( 1 ) Horizontal pipe: As you can see the image below, air bubbles stay on the top of higher place of pipeline. However, if with not enough pressure, water stage become lower, and the pipe is not easy to be filled with liquid. However, at this time, if the installation location is at the lower place of concave pipeline which is filled with liquid for sure, the measurement will works as expected definitely.
( 2 ) Vertical pipe: LORRIC recommend to install paddle wheel flowmeter on the vertical pipe with liquid flowing to upstream. If the fluid flows from top to bottom in a pipe, the fluid will flow in a free falling pattern, leads to a noncontinuous vertical flow. In this position the flow is not stable and flow volume measured is not accurate. On the contrary, if the fluid flows from bottom to top in a pipe. With the help of gravity, the flow rate will remain relatively stable. Therefore, the measurement is more accurate.
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