The user can plug any accessory directly into the ball, like a lamp to study or a cell phone charger.
用户可以将任何配件直接插到球上，比如学习用的台灯或者手机充电器。
2
V-port trim has a more linear throttling curve than plug or ball discs, but none of these trims are recommended for continuous severe throttling which may require using a control valve.
A type of dual slots helix hoisting composite valve switch mechanism which is suitable for ball valves, butterfly valves and plug valves is introduced.