During the process, raw material, intermediate products and byproducts include Si powder, Cl2 , H2 , HCl, SiHCl3 , SiH2 Cl2 and SiCl 4 , therefore valve’s design must be able to deal with these medium, especially the highly abrasive Si powder. The chemical compounds are extremely dangerous. H2 and SiHCl3 are easily combustible......