Transmission : normally meshed helical gear drive, coupling sleeve shift and two lever operation. The transmission has five forward speeds and four backward speeds .
变速箱采用常啮斜齿轮传动，结合套换档、双杆机械操纵，前进五档、后退四档。
2
The handle (or gear box) of butterfly valve can be rotated backward or forward for 180 degrees.
蝶阀的把手（或齿轮 箱）是可以反转或正转180度操作。
3
The adjustor consists of gears and worm-gear reducer, and the automatic controller circuit consists of pulse period discriminator, forward switch, backward switch and protector circuit.