Development history of plastic ball valve

As early as the 1880s, the United States began to design ball valves, but at that time, the lack of appropriate sealing ring materials and production technology limited the development of ball valve products. Until the 1950s, the emergence of elastic sealing plastic materials such as polytetrafluoroethylene and the development of machine tool industry made the development of plastic ball valve products turn around and get rapid development. Ball valve is mainly composed of valve body, valve seat, ball, valve rod, handle (or other driving device). The main function of the development history of plastic ball valve is to cut off or connect the fluid channel in the pipeline. Its principle is simple: apply a certain torque on the upper end of the valve rod by the help of the handle or other driving device and transfer it to the ball, rotate 90 degrees, make the channel of the ball coincide or perpendicular to the center line of the valve body channel, and complete the full open or full close of the ball valve. Plastic ball valve is the valve with the ball as the opening and closing parts. With the rapid development of processing technology, testing technology and intelligent control technology, as well as the emergence of various new sealing materials, the development history of plastic ball valve products will be more and more widely used. At present, ball valve products are not only used in general industrial pipelines, but also in West to east gas transmission, coal to oil engineering, nuclear industry and aerospace industry transmission pipelines.

Plastic ball valve classification:

There are many types and specifications of plastic ball valve, and new products and structures are still emerging. According to the characteristics and uses of ball valves, they can be divided into several types. According to the support mode of the ball, it can be divided into floating ball valve and fixed ball valve, and according to the installation mode of the ball, it can be divided into top mounted (top mounted), side mounted, oblique mounted, etc. For side mounted ball valve, according to the use of different occasions and the size of the diameter, according to the ball structure classification. Integral ball valve, hemispherical ball valve, according to the purpose of ball valve: the above describes the classification of various general purpose ball valves according to the structural form. The ball valves used under special working conditions can be divided into vacuum ball valve, low temperature and ultra-low temperature ball valve, high temperature ball valve, heat preservation ball valve, corrosion-resistant lining ball valve, wear-resistant ball valve, receiving and serving ball valve, all plastic ball valve and multi-functional ball valve according to the purpose of the ball valve.

Connection mode of plastic ball valve:

Butt welding connection: the outer diameter of the valve connection part is equal to the outer diameter of the pipe, and the end face of the valve connection part is welded relative to the end face of the pipe;

Spigot bonding connection: the connection part of the valve is in the form of spigot, which is bonded with the pipe fittings;

Electric fusion socket connection: the valve connection part is the socket type with inner diameter laying of electric hot wire, which is connected with the pipe by electric fusion;

Socket hot-melt connection: the connection part of the valve is in the form of socket, which is connected with the pipe by hot-melt socket;

Socket bonding connection: the connection part of the valve is in the form of socket, which is bonded with the pipe;

Connection of rubber sealing ring at the socket: the connection part of the valve is the socket type with rubber sealing ring inlaid, which is connected with the pipe by socket;

Flange connection: the valve connection part is in the form of flange, which is connected with the flange on the pipe;

Threaded connection: the connection part of the valve is in the form of thread, which is connected with the thread on the pipe or pipe fitting;

Flexible connection: the valve connection part is in the form of flexible connection, which is connected with pipes or pipe fittings.

A valve can have different connections at the same time.