DEVICE FOR PROTECTION OF BACK OF WELD IN WELDING TUBULAR ARTICLES Russian patent published in 1995 - IPC

FIELD: welding technique. SUBSTANCE: device has taper plate-type members 1 and 5 between which splitter 7 is mounted. Outer plate-type member 1 whose inner diameter is equal to 1.2- 1.3 of the outer diameter of the inner plate-type member is mounted on hollow rod through which inert gas is supplied. Gas is admitted to space between taper members where- from it is fed to root of weld through splitter 7. Taper angle of plate-type taper members is equal to 30-40 deg. gas is fed along inner surface of pipes being welded. Rod and taper plate- type members may be made of flexible material. EFFECT: enhanced reliability. 2 cl, 2 dwg