The high-pressure saturated steam flowmeter is selected for reducing diameter to ensure normal operation at low flow rates. Usually, cases of exceeding the instrument range are relatively rare in industrial sites. The situation of low traffic is very common. If the analysis results indicate that large flow rates must be given more attention, then larger caliber flow meters can be used. However, the focus on small flow rates must be set aside, and flow meters should be equipped with small flow cutoff. Experience tells us that when this situation occurs, it is usually small or large.

When installing a high-pressure saturated steam flowmeter, the following precautions should be taken:

1. Installation location

The selection of installation location requires the operator to carefully understand the working conditions, including the material of the inspected pipeline, the outer diameter of the pipe, the thickness of the pipe wall, the material and thickness of the lining inside the pipe, and the specific information of the medium inside the pipe, and verify it to ensure the accuracy of the measurement. The installation of standard meters should be kept away from upstream and downstream disturbance sources to avoid harmful vortices and other situations. However, it is common for the installation requirements to not be met in actual on-site situations. This requires on-site operators to have considerable practical experience, choose the correct location and method for installation, and avoid the occurrence of significant errors.

2. "V" installation method

When allowed in straight pipe sections, installation should be done using the "V" - shaped method. Because the "V" installation method is used, the two transducers are located on the same side of the pipeline, making it easy to install them on the centerline of the pipeline; And on the same side of the pipe wall, the external conditions are almost *, which can reduce the amount of error caused by parameter settings to a low level. Although the use of the "Z" - shaped installation method reduces the sound path by nearly half, the opposite installation methods on both sides make it difficult for the transducer to be on the same pipe diameter plane, resulting in a decrease in the quality of the received ultrasonic signal, which inevitably leads to significant measurement errors.

3. At the same time, we believe that the repeatability requirements for portable devices used for standard table comparison are limited.

The online calibration method for flow meters is feasible. Although there are some differences between the online calibration method and the calibration on laboratory water flow calibration devices, it also alleviates and solves to some extent the problem of large caliber flow meters not being able to be disassembled for calibration.

Easy to be affected by vibration interference, well-designed systems can eliminate interference through hardware and digital signal processing to obtain stable signals. A long straight pipe section is required before and after installation, and some manufacturers can provide a design for reducing the diameter inside the flowmeter, greatly reducing the need for users to specifically equip straight pipe sections. If a valve is installed near the upstream of the installation point, constantly opening and closing the valve will have a great impact on the service life of the flowmeter, and it is very easy to cause * damage to the flowmeter. Try to avoid installing flow meters on very long overhead pipelines as much as possible. Over time, the sagging of the flow meter can easily cause seal leakage between the flow meter and the flange. If installation is necessary, pipe fastening devices must be installed at 2D positions upstream and downstream of the flow meter.

Installation method of high-pressure saturated steam flowmeter:

(1) The fluid must fill the pipeline and throttling device, and flow continuously through the pipeline; (2) The fluid flow rate does not change over time or changes very slowly; (3) The fluid does not intersect when passing through the throttling element;

(4) The fluid must be a Newtonian fluid, which means it is physically and thermodynamically uniform, single-phase, or can be considered single-phase, including mixed gases, solutions, and colloids with dispersed particles smaller than 0.1 m Solid particles with a mass fraction of no more than 2% uniformly dispersed in gas, or bubbles with a volume fraction of no more than 5% uniformly dispersed in liquid, can also be considered as single-phase fluids, but their density should be taken as the average density; (5) Before flowing through the throttling element, the fluid stream is parallel to the axis of the pipeline without any swirling flow.