| 摘要 |
PURPOSE:To manufacture the ball valve having a very high spherical surface accuracy under a low cost by a method wherein the ball valve, equipped with a spherical surface as a contacting surface against the valve seat and operated into a constant direction only, is manufactured by processing a true spherical steel ball body sold in a market. CONSTITUTION:A ball valve 11 is equipped with the smooth seat 12 consisting of ring-shaped circumferential groove and a protruded section 13. The true spherical steel ball body sold in the market as a material is utilized to make the ball valve by a method wherein the steel ball is gripped to rotate it and the side spherical surface thereof is cut by lathe or ground to a cylindrical or a converted conical configuration remaining the protruded section 13. Accordingly, the processing is very easy and the valve having a very high spherical surface accuracy may be manufactured. |
