Gearing is generally applied to valves to make operation easier. The gearing may be of the spur, bevel or worm type - any of which may be applied to Velan valves.

• 采用齿轮执行机构通常是为了使阀门操作更加容易。齿轮执行机构可能是正齿轮、锥齿轮或蜗轮,任何一种都可以应用在Velan的阀门上。