Instrument tube valve parts - how little do you know about it?

Gauge valve parts refer to the parts, fittings, valves, etc. on the gas pipeline that connect the instruments or valves.

At present, domestic demand for natural gas continues to grow, and the construction of natural gas backbone pipeline networks continues to advance. A number of large-diameter, high-pressure natural gas pipeline networks, including Shaanxi-Beijing, West First Line, and West Second Line, have been completed and put into production. Whether the valves on the natural gas pipeline process system can normally perform shutdown isolation will directly affect the normal operation of the main gas pipeline network operation and maintenance work.

As an instrument tube valve that connects an instrument or a valve, it directly affects the probability of running, running, dripping, and leaking of the pipe and valve.

Meter tube valve connection form

Various valve connection methods include: flange connection, clip connection, butt welding connection, screw connection, clamp connection, clamp connection, self-sealing connection and other connection forms.

Flange connection type: Flange connection is a flange on both ends of the valve body, which corresponds to the flange on the pipe and is installed in the pipe through the bolt fixing flange. Flange connections are the most used form of connection in valves. The flange has convex (RF), flat (FF), convex and concave (MF) and so on.

Type of clip connection: The valve is installed in the middle of the two flanges. The valve body usually has positioning holes to facilitate the installation and positioning, and the bolts directly connect the valve and the two pipes together.

Welding connection type is divided into butt welding connection and socket welding connection. Butt welding connection: The two ends of the valve body are processed into butt welding groove according to the requirements of butt welding. Corresponding to the pipe welding groove, the pipe is fixed on the pipe. Insert welding connection: The two ends of the valve body are processed according to the socket welding requirements, and the pipe is connected by socket welding.

Threaded connection type: Threaded connection is a simple connection method and is often used for small valves. The valve body is processed according to each thread standard, and there are two kinds of internal thread and external thread. Corresponds to the thread on the pipe.

Card sleeve connection type: Card sleeve connection, developed in recent years in China, its connection and sealing principle is that when the nut is tightened, the ferrule is subjected to pressure, so that the blade part bites into the outer wall of the tube, and the outer conical surface of the ferrule is in turn Under pressure, it is in close contact with the inner conical surface of the joint, so that leakage can be reliably prevented. Such as instrumentation valve.

Clamp connection type: This is a quick connection method that requires only two bolts and is suitable for low-pressure valves that are frequently disassembled. Such as sanitary valves.

Internal self-tightening connection type: The above various connection types use external force to counteract the medium pressure and achieve sealing. The following describes the self-tightening connection using media pressure. Its sealing ring is mounted on the inner cone, forming an angle with the opposite side of the medium, the medium pressure is transmitted to the inner cone, and is transmitted to the sealing ring. At a certain angle on the cone surface, two force components are generated. The centerline of the valve body is parallel to the outside and the other is pressed against the inner wall of the valve body. The force behind this is self-tightening. The greater the medium pressure, the greater the self-tightening force. So this connection form is suitable for high pressure valves. Compared to flanges, it saves a lot of material and manpower, but it also requires a certain amount of preload to make it reliable when the pressure inside the valve is not high.

There are many forms of valve connection, for example, some small valves that do not have to be removed are welded together with the pipe; some non-metal valves use socket connections, and so on. The valve user should treat it according to the situation.

At present, there are many brands of instrumentation valve parts, such as imported instruments such as E+H, K-TEK, EDM, SOR, Siemens, Bimanster, Mesomile, Swagelok, and others.

How to maintain the instrument tube valve

Regular discharge of pollutants is the process inspection and routine maintenance required for the instrument tube valves. The regular discharge of pipe fittings mainly includes the discharge of pollutants and the regular purging.

The regular discharge of pollutants should be noted that, before the discharge of pollutants, it must be contacted with the process personnel to obtain approval of the process personnel; at the same time, before the discharge of the flow or pressure regulation system, it should be automatically switched to manual, to ensure that the opening of the regulating valve does not change; In addition, the instrument tube fittings for differential pressure transmitter, before the discharge of the three valves positive and negative pressure valve shut down; place the container under the sewage valve, slowly open the positive and negative pressure tube drain valve, so that the material and dirt into the container , to prevent the material directly discharged into the trench, otherwise, one to pollute the environment, and second, to cause waste; due to the poor quality of the instrument valve, the sewage instrument valve will turn off several times after the condolences, emergency measures are blinded, ensure that the sewage valve Do not leak, so as not to affect the measurement accuracy. Open the positive and negative pressure valve of the three valve group, loosen the sewage (exhaust) screw on the differential pressure transmitter body to discharge the dirt, complete the tightening of the screw, and observe the on-site indicator until the output is normal. If the system is adjusted, it will be switched manually. automatic.

Instrument tube purging is a method that uses blowing or flushing to make the measured medium not directly contact with the meter component or measurement pipeline to protect the measurement instrument and perform measurement. Insufflation is the continuous and quantitative blowing of gas into the measuring object through the measuring line. The flushing liquid is continuously and quantitatively poured into the liquid through the measuring line to the measuring object. When the corrosive, viscous, crystalline, meltable, and precipitated media are measured and the isolation method is difficult to meet the requirements, purging is used.

In recent years, the rapid development of China's industry, which is particularly important for the valve and fittings industry, the valve and fittings industry has a huge room for development, is to obtain greater development through transformation and upgrading.

At the same time, the rapid development of the instrument tube valve industry has also exposed some problems and faced many challenges. Only by accelerating industrial restructuring and upgrading can we achieve faster and better breakthroughs in the quality and efficiency of pipe and valve products.