What are the advantages and disadvantages of the plug valve application?

The advantage of plug valve applications is that the body mounted on the top of the whole is equivalent to the ball valve mounted on the top of the whole. It is a completely different type and application than two - or three-chip ball valves.

Let's take a look at the advantages and disadvantages of the plug valve and the main uses of the plug valve:

1, the valve body adopts the integrated top installation design, simple structure, convenient online maintenance, no leakage of the valve body, pipeline system strength is high.

2. The corrosive medium in the chemical process is very strong. In chemical environments, the valve body is often corroded by medium. Therefore, the valve body used in the chemical process must have strong impermeability. In addition, the valve body of the plug valve is resistant to intergranular corrosion and is a G-rated casting. Casting quality is 2 grade, precision is 5 grade

3, the opening and closing part of the cock is completely covered by the bushing, the valve body and the cock are not worn, the bushing and the top seal replacement is convenient and economical. You can complete up to 300 valve maintenance and updates. Compared with metal-sealed ball valves in this range, °C has a significant competitive advantage in long-term use.

4, the whole machining surface of the plug valve is only the top surface and the flange, the other parts are one-time casting. No handling in valve body. Compared with ball valve, it has the advantages of small processing capacity.

5, the plug valve can be designed to perform specific functions according to user needs. Plug valves are the ideal choice for custom - made valve products. The plug valve allows you to easily customize the process. It can meet the requirements of three, four, five, six, double or multi-valve groups and various sheathing. For example, the six-way distribution valves used in the polyester industry are customized plug valves according to the patentee's requirements, which increases the difficulty of ball valves as custom valves.

6, the current plug valve without clearance or end seal. Ball valves are designed with or without clearance, but only ball valves are designed so that the clearance between ball and body is between 1 and 3 mm. The benefits of coating surface sealing applications cannot be realized. Due to this characteristic, the plug valve is easy to crystallize and sticky, suitable for handling many harsh media such as fluid corrosion and sediments containing catalytic particles.

7, coating bushing has surface sealing performance, can be strictly controlled & "zero leakage &"; API598 Soft seal seat test requirements meet TA-Luft or iso15848 stem seal requirements. The general characteristics of the plug valve are long service life and high reliability. Suitable for a variety of corrosive, abrasive, toxic, continuous operation and other media and equipment, has application advantages in the chemical industry. A wide range of applications.

Disadvantages of the plug valve

1. The surface seal design increases the requirement of driving torque. For pneumatic actuators, the use of actuators and accessories larger than the ball valve will increase the cost of the user's. For example, in the PP process, the main globe valve uses a plug valve instead of a ball valve, and the high-frequency on-off valve uses a ball valve, so the pneumatic plug valve is basically used in the main cut-off position. I can. The use of plug valves during adjustment is not fully recommended. The high frequency switch is not an advantage of the plug valve. High reliability stop valve.

2, in some applications, due to improper selection of bushing material or improper design of the valve body, will lead to PTFE bushing expansion, so that the bushing deformation of the release zone valve required to drive torque changes several times. In order to use appropriate materials, strong pertinence, basically avoid this situation.

3, the one-time investment of the plug valve is higher than the ball valve. However, as the reliability and life-cycle cost of plug valves become accepted by domestic users, more and more users will need to continue with the original process design of plug valves, and the decision to switch to ball valves will gradually decrease. .