Questions regarding pressure gauges, pressure transmitters, and valve assemblies
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On the gas pipelines in the production process, are the threads of the pressure gauge connection tubes generally metric or imperial? Are they internal threads or external threads? What about pressure transmitters? Are there any requirements for this standard? The operating medium is natural gas; what welding method is used during installation, socket welding?
This post was last edited by yunrun on 2018-9-4 at 18:30. The pressure guiding pipe installed on the gas pipeline is a seamless pipe without any threads. Welding at the end of the pressure guiding pipe where it meets the gas pipeline is usually done using socket welding, while the other end of the pipe is typically connected to a pressure gauge connector or an instrument valve, with butt welding being the most common method in such cases. The gauge connector or instrument valve used to install a fixed pressure gauge has threads (either internal or external), and the size of these threads – whether they are internal or external – depends on the thread size and design of the pressure gauge. The thread size of the gauge connector or instrument valve is the same as that of the pressure gauge, but their design is opposite to each other; for example, if the pressure gauge has external threads, then the gauge connector will have internal threads, and vice versa. Pressure gauges are classified according to their threaded connections and installation methods. ① General pressure gauges: Based on threaded connections and installation methods, they are divided into directly installed pressure gauges, embedded (panel-mounted) pressure gauges, and protruding (wall-mounted) pressure gauges, as shown in the table below ； Location and installation method of the pressure gauge’s threaded connection. Classification of pressure gauges: yunrun.com.cn/tech/2177.html http://yunrun.com.cn/upload/201809/04/201809041528503043.png ② Precision pressure gauges: The installation methods include radial direct installation and embedded installation ； ③The relationship between the nominal diameter of the housing and the dimensions of the threaded connection is shown in the table and the figure below: http://yunrun.com.cn/upload/201809/04/201809041551378196.png. The relationship between the nominal diameter of the pressure gauge housing and the dimensions of the threaded connection can be seen here: http://yunrun.com.cn/upload/201809/04/201809041601085727.png
There are no requirements regarding the welding method; either socket welding or butt welding can be used. You can refer to the installation manuals for automated instruments. The diameter of pressure transfer pipes generally ranges from 18 mm, 14 mm, to 12 mm, depending on the pressure rating. For pressures up to PN63, a 14×2 pipe is sufficient; pressure gauge connectors are welded to both ends, and clamp-type connectors are usually chosen as they facilitate disassembly during maintenance. Thread size: M20×1.5
It’s described in great detail above; thumbs up: lol
Give a thumbs up to the person in post 2 – the explanation is quite comprehensive
It’s described in great detail above; thumbs up