First, the ball valve and butterfly valve

Ball valves and butterfly valves are the most widely used and widely used valves in today's valves. They are easy to operate and function as a cut-off and cut-off for pipeline media.

• The ball valve is mainly used in the pipeline to cut, distribute and change the flow direction of the medium. It only needs to be rotated 90 degrees and the torque can be closed tightly. There are many different categories. According to the function, it can be divided into bypass valve, air valve, pressure relief valve, sewage valve, etc.; according to the transmission can be divided into: pneumatic ball valve, electric ball valve, hydraulic ball valve, gas-liquid ball valve, electro-hydraulic ball valve, turbine transmission Ball valve, etc.; according to the shell / body material can be divided into: metal material valve, metal valve body lining valve, non-metallic material valve.

Ball valve

• The butterfly valve, also known as the flap valve, is a simple regulating valve, which is mainly composed of a valve body, a valve stem, a butterfly plate and a sealing ring. The valve body has a cylindrical shape with a short axial length and a built-in disc. There are also many types of classifications. The driving method is divided into electric butterfly valve, pneumatic butterfly valve, hydraulic butterfly valve, manual butterfly valve, etc.; according to the structure, it is divided into central sealing butterfly valve, single eccentric sealing butterfly valve, double eccentric sealing butterfly valve, triple eccentric sealing butterfly valve, etc.; according to working pressure, it is divided into vacuum butterfly valve, Low pressure butterfly valve, medium pressure butterfly valve, high pressure butterfly valve, ultra high pressure butterfly valve, etc. According to the connection method, it is divided into a wafer type butterfly valve, a flange type butterfly valve, a lug type butterfly valve, a welded butterfly valve and the like.

Butterfly valve

Second, the difference

1. The structure is different

Structurally speaking, the biggest difference between the two is the opening and closing. The opening and closing member of the butterfly valve is a plate, and the opening and closing member of the ball valve is a ball. The butterfly valve can adjust the flow rate through the opening degree, but the ball valve cannot.

The butterfly valve consists of four parts: the valve body, the valve seat, the valve plate and the valve stem. The fittings are leaking outside and can be seen by the naked eye. The ball valve is made up of the valve body, the valve core (which is a round ball), and the valve. The rod is composed of a valve core inside the valve body, and only a part of the naked eye can be seen.

2. Sealing and caliber are not the same

The butterfly valve is characterized by quick opening and closing speed, simple structure and low cost, but the tightness and pressure bearing capacity are not good. The ball valve can be quickly opened and closed to achieve a complete seal at high pressures and temperatures. Therefore, the sealing performance of the ball valve is better than that of the butterfly valve. However, due to the limitation of volume and opening and closing resistance, the ball valve is difficult to achieve large diameter, and the structural principle of the butterfly valve is especially suitable for making large diameter valves.

3. The temperature and pressure level are different.

From the point of view of the use temperature, the ball valve is not suitable for the steam medium due to the sealing material and structure, and the butterfly valve can be used for the conventional saturated steam medium for heating (below 350 degrees).

The butterfly valve structure is relatively simple, and the butterfly valve is generally used for low pressure, and the ball valve structure is relatively complicated and more resistant to high pressure.

4. Operating torque

In terms of operating torque, the butterfly valve is a three-eccentric metal sealing butterfly valve, so its opening and closing torque is very small, and as the diameter of the ball valve increases, the contact area of the sealing surface also increases squarely, so the large diameter ball valve The opening and closing torque will be very large.