2,000 Ton Forging Press

5000 ton forging press picture

Problem: The column nuts on this press had a long history of coming loose. Previously, heating rods were used to obtain 2,000,000 lbs of preload per column.
Workers needed to tighten the column nuts weekly, and years of operation with the loose column nuts had detrimental effects to other components. The press eventually needed to be overhauled.

Solution: A new base, top platen and columns were manufactured, and the column nuts were upgraded to Superbolt® split tensioners. The split design assured there would not be complications while installing the nut onto the main thread, such as thread galling and seizing. The split design greatly eases assembly, especially for overhead installation below the press. To install the lower nuts, the column was lowered by crane and the two nut halves were easily installed.

Superbolt® Tensioners were also chosen in order to achieve a higher column preload. The jackbolts were tightened to 285 ft-lb to achieve 3,444,000 lbs of preload. An IR 252-3/4” impact was chosen for initial tightening, and final tightening was done with a torque wrench. Two workers tightened the bottom nuts in about two hours each, and one worker installed the top nuts in less than one hour each.

IMAGES:

(Top) Four tensioners used on top platen.

(Middle) (8) 14 3/4” Split Tensioners.

(Left) Tightening of four lower tensioners. 3/4” impact was used to build up column prestress. Final tightening was done with a torque wrench.