Patent ID: 6899599
Filing Date: 2005-05-31
Classification: B21K,B23P,B24B,F16K

Abstract:
1. A manufacturing process to make a ball valve comprising the following steps: a) preparing a pair of flat circular metallic plates each of which has a rectangular indentation in a predetermined position along a circumferential edge thereof; b) putting said plates on one by one basis between an upper mold and a lower mold in a punching machine, said plate being punched into a bowl shaped semi-finished product each of which has a rectangular indentation in a rim and a circular bottom on specific surface; c) placing each of said bowl shaped semi-finished products in a semi-circular shaped mold and using a sharp punch bar to punch said circular bottom of each bowl shaped semi-product into a circular opening and said bowl shaped semi-products into a piece of hemi-spherical shaped semi-finished products; d) combining each pair of said hemi-spherical shapes together to complete a spherical shaped ball valve by welding means and their indentations being aligned with each other to form a rectangular retaining through hole which is provided to connect a valve stem; e) trimming and grinding uneven connection seam of each ball valve and performing a global shaped solidification method; f) polishing outer surface of each of said ball valve by inserting a rotatable cylindrical bar through aligned circular openings and adapting a polish machine which has an inward curved semi-circular surface in a lateral side engaged with outer surface of said ball valve and rotating said bar to polish said ball valve until that the surface of said ball valve becomes smooth, then removes said bar; whereby, a qualified valve ball is therefore finished.