1. Only one operator;
2. Security;
3. Not to loose packing
4. Ball can be fixed at any given position,
5. The transmission input shaft on the ball than the fixed,
6. Ball position indicator in the striking position.
After three requests for transfer were spraying the net, especially important.
If the ball valve for cryogenic liquid, then there is a range of additional playing gear requirements:
1. Heat transmission should be sufficient people to make exercise part of the oil from freezing property;
2. Material does not occur at low temperature cold crisp;
3. There should be light drive home the local accumulation of water, otherwise it will freeze the phenomenon occurs;
By passing through the hand wheel of the valve stem forces the way, all the manual ball valve device can be divided into two categories:
1. Not borrow the manual transmission device;
2. Device with the manual transmission;
