It was very difficult for high cr cast Fe hollow ball valve in investment casting due to its internal hollow and full close as well as high crack susceptibility.
高铬铸铁空心球阀的精密铸造难度较大，球阀内部必须空心、全封闭，同时高铬铸铁的裂纹敏感性极强。
2
When joining the fixed end of a single union valve, place the ball in the open position to allow for proper drying and to avoid primer or solvent cement contacting internal components of the valve.