embedded valve seat when the valve seat sealing surface defects cannot be directly repaired by grinding or reaming method, can be embedded by the valve seat, then reaming gas valve seat sealing surface to restore the air tightness. For directly from the valve seat on the cylinder cover can be processed, the size of the valve seat is embedded after cutting and valve seat. For the original cylinder with valve seat cover, valve seat can be removed, according to the original size inlaid with the valve seat, can also be appropriate to expand the valve seat bottom hole size, inlaid with increased the outer diameter of the valve seat. Inlaid with the valve seat, the first valve seat with liquid nitrogen cooling from 5 to 10min, and then quickly pressed into the cylinder head, cylinder cover or heating quickly after pressed into the valve seat. It will be the valve seat under normal temperature directly into the cylinder head, otherwise it will damage the valve seat, the valve seat valve seat bottom strain, while pressing is easy to fall off. In addition, reliability of the cylinder cover, can not arbitrarily expand the valve seat after the valve seat insert bottom hole size weight.