What are the differences between vacuum ball valve and vacuum butterfly valve?

What is the difference between a vacuum ball valve and a vacuum butterfly valve?

1. The structure is different

Structurally speaking, the big 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 by the opening degree, but the ball valve can not.

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 body 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, in comparison, the sealing performance of the ball valve is better than that of the butterfly valve. However, due to the limitation of the volume and the opening and closing resistance, the ball valve is difficult to achieve a large diameter, and the structural principle of the butterfly valve is particularly suitable for making a large diameter valve.

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.