Your column rubs against the side of the opening of normal unions when they are used to repair breaks on a caged column. That's why angled unions are also known as column repair unions. The 18 degree angle design eliminates asymmetric stresses on columns at the union opening when installed on-column (standard 8” coils). If you want your on-coil repair to last, use an angled union. These unions seal on column ODs from 0.32mm to 0.74mm (0.10mm to 0.53mm bore).
P/N: 3-2002A (Single column repair union) -- $11.00 ea
P/N: 3-2002A-5 (5 pack of column repair unions) -- $10.45 ea
P/N: 3-2002A-10 (10 pack of column repair unions) -- $9.90 ea
P/N: 3-2002A-25 (25 pack of column repair unions) -- $9.35 ea
P/N: 3-2002A-100 (4 packs of 25 column repair unions) -- $8.80 ea