主要工艺形式有:. e. w: f2 {; `7 R5 h' G1 u" k
1. All continuously welded or brazed., B1 f( N0 }' F6 y. H
2. Tack or spot weld (and sealed or unsealed)5 v( d7 A6 \! K. u& A! p8 |( ?* i
3. Seam locked (and sealed or unsealed) 4 U( h' ]% a) A) l' u! Q4. Rivet, screw, or punched-die-stamp locked (and sealed or unsealed)