Problems with differential pressure flow meters on steam pipelines

A condensate tank must be installed, and the pressure guide tube must be filled with condensate water without any air. When it is first put into use, the root valve should be opened, and the three-valve assembly before the transmitter should be closed. After condensate water accumulates in the pipeline, the air should be vented before the gauge is turned on.

A condensation tank is not necessarily required; it must be filled with condensate before starting operation.

Actually, it’s not necessary to use a condensation tank; rolling up the tubing is also an option, though it requires a slightly longer length, usually around seventy to eighty centimeters

It depends on the specific situation; if the temperature difference is close to the steam pipeline, it’s best to add a condenser. If the distance is large, it can be omitted; the pressure guide tube is long enough to hold the condensate. Before starting the pump, open the root valve first; do not open the three-valve assembly. Once it is filled with condensate, then put it into use.

I simply removed the condensation tank and installed it directly, and I deliberately placed the gauge close to the sampling point, providing appropriate isolation for that part of the gauge to prevent damage from high temperatures. At the beginning of operation, the valve can be closed partially or water can be used for cooling to produce condensate. Processing measurements in this way also yields accurate results (two different types of meters were compared side by side); especially in winter, no heating is required and no further action is needed. If you find that the measurement data for logistics calculations are stable and reliable, then there is no need for calibration. Steam flow measurement at 5 kilograms and 40 kilograms – it has been operating without maintenance for over a decade, and the gauge has never failed. Aren’t you jealous? !

Think differently: instead of using a condenser tube, use a pressure transfer tube filled with silicone oil; pressure is transmitted through the diaphragm and the silicone oil, and thus the problem is solved.

As long as the pressure tapping method is installed correctly, it’s fine without a condensation tank; the meter can be connected directly. The function of a condensation tank is nothing more than to facilitate condensation, but pressure guide tubes can also achieve condensation. The diaphragm box of the transmitter cannot withstand high temperatures for long periods, but it can handle them for a short time, as long as the balance valve of the three-valve assembly is closed. However, I believe that prolonged exposure to such conditions may reduce the transmitter’s service life; therefore, it is better to wait until there is condensation water in the pressure guide tube before opening the shut-off valve, provided that there is enough time to do so. But I have never done this before; every time a problem is resolved, I put it into use right away, as I don’t want to wait.

It’s really hard to understand what the original poster is trying to say; just find a watch on site and you’ll understand.

This post was last edited by 1111111 on 2019-7-24 08:04. What grade of silicone oil are you using? I vaguely remember that, first, the density of silicone oil is less than that of water, around 0.94 g/cm3. II. The coefficient of thermal expansion of silicone oil is higher than that of water, by about 5 times. By doing this, you will encounter the following problems: First, condensation will always settle to the bottom of the silicone oil. II. The condensate will eventually displace all the silicone oil. III. Before the silicone oil is exhausted, the amount of condensate in the two pressure sensing tubes is not guaranteed to be equal; if it is not equal, the liquid column pressures will differ – which will introduce additional errors. {:2_45:}