It mainly used for boring and repairing the gas valve seats hole,when equipped with all sorts of clamping device,It can manufactrue the gas valve seats hole for cylinder cover with various angles,when equipped with boring-drilling tolls,It also can bore ,drill,ream the pipe seat hole of gas valve or ream and repair it. Structure characters 1,It adopts the air-floating work table,which can be easy centering of work piece and spindle. 2,The feeding system of the tools has two ways:rough and finishing,which can improve the work efficiency and processing rate. 3,It adopts vertical rectangle guide-way,which can increase the rigidity of the machine ,and guarantee the processing precision for all kinds of the gas valve seats hole on different diameter. 4,It equips with the vaccum examining device,for quickly measuring the work piece.Spindle travle 180mm