Precautions for installing tower-type (V-cone) flow meters in steam pipelines
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The company previously used DN80 tower-type flow meters to measure natural gas; they were removed due to accuracy requirements and are now idle. They are intended to be used in steam pipelines, which have a DN50 diameter, so the pipes will need to be modified. It has been determined that a straight pipe section with 10 inches in front and 2 inches at the back is required. However, the differential pressure transmitters and pressure transmitters used in tower-type flow meters have temperature-related issues: 1. The temperature of the steam is generally around 150 degrees, while it seems that the maximum temperature tolerance of the differential pressure transmitters is 120 degrees; therefore, a condenser is needed. It’s possible to build such a condenser oneself – what is its structure? 2. Other companies have made changes similar to mine: they added an annular signal tube to the pressure transmitter in order to reduce heat; liquid should accumulate inside that annular tube, which would likely affect the pressure.
For this tapered installation, it is necessary to ensure that there are at least 10 units of straight pipe section in front and 5 units behind. As for whether to install a condensation tank or a condensation elbow, it is recommended that you install a condensation tank if you have the means to do so. To protect the transmitter, it only costs 300 yuan per set – two of them are not worth much at all. Your main problem isn’t related to the installation itself; rather, the differential pressure needs to be recalculated. The range of the original transmitter does not match the flow rate under your current conditions. You need to use the design calculations that came with the original V-cone, along with the current operating parameters (the inner diameter of the pipe after the modifications, pressure, temperature, and maximum flow rate). Based on the known taper of the V-cone and these new operating parameters, you can calculate the differential pressure value. Only then can you adjust the transmitter using a handheld programmer so that it can function properly
This gentleman is absolutely correct. I have had the manufacturer modify the parameters of the secondary instruments, and they have also calculated the range for the differential pressure transmitter. Now all that remains is the issue of installation – how to protect the differential pressure and pressure transmitters
You can make the condensation tanks by yourself, but the two made must be identical. The condensation bend is generally used for individual pressure measurements. During installation, the two condensation tanks must be at the same height.
Are there any structural diagrams for this type of condensation tank? ? Baidu was unable to find it
It’s simply a sealed tank with an inlet on the upper side and an outlet on the lower side. The positions of the two inlets should be at the same height
Having to do it yourself means you also have to buy materials, weld, and paint – isn’t that troublesome? A pair costs only two or three hundred yuan; if you need the drawings, add me on QQ at 290666948
As for the issue of temperature exposure for pressure transmitters, the user doesn’t need to use a single wire; installing a condensation bend or creating a U-shaped bend during the welding of the pressure lead will suffice, as the transmitter’s diaphragm box cannot come into contact with steam.