Plug valve VS ball valve   
The plug valve with one-piece upper inlet design has many similarities to a one-piece upper inlet ball valve. Strictly speaking, the ball valve and the plug valve are the same types of valve due to their similar function and characteristics, and both have a wide range of applications. Today we are going to introduce the difference of plug valve and ball valve.

The plug valve also known as a tap valve, a rotating plug valve, is a type of old line valve. The combined "plug" (mostly conical or cylindrical) valve and the surface body of the conical seal hole move depending on the body of the plug around the center line of the valve to achieve open and close. It is mainly used to cut, distribute and change the media flow. The plug valve is simple in structure and small in size. It can be opened and closed only with 90% rotation. It is widely used in occasions of low pressure, small and medium diameter or low temperature. The sealing surface of the plug valve is easy to use, it is also easy to get stuck in case of high temperature or high pressure, it is not suitable to regulate the flow.

The ball valve evolves from the plug valve with a ball as its closing parts, towards the center of the valve to achieve opening and closing, which is mainly used to cut, distribute and change the flow direction of the medium. Ball valves can be sealed tightly only with 90 degrees of rotation or with a small torque. The full horizontal of the valve body cavity provides little resistance through the flow path for the medium. The main characteristics of the ball valve are the compact structure, easy to operate and maintenance, suitable for water, solvent, acid and natural gas and other general means, also suitable for working conditions of aggressive media, such as oxygen, peroxide hydrogen, methane and ethylene. theball valve The body can be a piece, it can also be combined. In general, ball valves are considered to be the most suitable for direct opening and closing, but recent developments have been designed for flow regulation and control.

Plug valve VS ball valve

Diffe rental principle

The ball valve develops from the plug valve. They have the same 90 degree rotation operation, but according to the "plug" it is a plug or a ball with a circular through hole or a channel that passes through its axis. The ball and the ports should look like this: when the sphere rotates in 90 degrees, it will appear as a sphere at the entrance and exit to cut off the flow. For the plug valve, the conical plug and the body surface formed by the conical pressure, the upper parts are sealed with gasket between the plug and the gap between the body. The plug valve is simple and often economical because it usually has no bonnets, but the handle is exposed outside at the end.

Different application

Plug valves offer better performance in the term of cut than ball valves, but that is obviously not noticeable. The sealing surface of the plug valve is much larger than the ball valve and provides a better sealing effect, but a larger torque and a small diameter. The ball valve is ideal for changing the middle of the pipe, not as a butterfly valve to avoid prolonged valve time due to medium erosion and loss of tightness. Now, the sealing effect of the ball valve has greatly improved with the progress of sealing technology, so we can say that the plug valve is used because the sealing requirements are strict, but the diameter is not large, And the ball valve is used for the sealing effect is not too strict and the diameter is large.

Plug valve is lower cost

For the plug valve, the "plug" is completely covered by the bushing, which causes the valve body and the plug to not wear out. The replacement of the bushing and the upper seal can complete the repair and upgrade of the valve, which can meet the long-term service requirements of 300 ℃. This has considerable competitive advantages over other sealed metal ball valves in this temperature range. In addition, the processing area of the shut-off valve is only the upper face and the flange, other parts, all cast molding in one step and the internal body does not need processing. Compared to the ball valve, it offers a low processing margin, by manufacturing the INCONEL, MONEL, HAST alloy and other special materials.