1. Summary

The ball grinding machines of model QTMJ are a new kind of product developed and designed by our company.This grinder can be designed and manufactured into three types, that is, single-headed, double-headed and multi-headed. The grinder is of advance technics, for it combines slow rotation of the globe(Ball)body and fast rotation of the grindstone. According to the technical requirements of the globe body to be grinded, select the appropriate grinding whetstone or grinding sand, grinding the workpiece roughly first and then subtly, or the globe(Ball)body and the valve seat grind each other.The machines are equipped with frequecy converters, and the grinding speed can be adjusted. After grinding, the roughness of the surface of the globe(ball) body can reach Ra0.4 μm, the ovality of the globe(Ball)body with the diameter ranging from 150mm to 200mm can be below 0.015mm, and the ovality of the globe body with the diameter ranging from 250mm to 350mm can be below 0.025mm, and the ovality of the globe body with the diameter ranging from 450mm to 550mm can be below 0.035mm. With this grinder, both the ovality and the surface roughness of the globe body can reach the technical requirements of the metal-to-metal seal ball valve.

2. Double-headed Globe Grinding Machine of Model QTMJ