Tube rolling occurs when the tube rotates due to inadequate friction between the tube OD and the hole in the tube sheet. This can cause increased expansion times and decrease the efficiency of the operator. In order to prevent tube rotation from occurring, the friction between the tube and tube sheet or the collar must be increased. This can be done by using one of the following methods:
Tubes can be staked or clamped on the tube’s opposite end so the tube cannot rotate.
Holding Expander Collar
Holding the tube expander’s thrust collar from rotating typically will keep the tube from spinning. The friction between the collar and tube faces will stop the tube from spinning.
Knurling Expander Collar
A knurled surface on the face of the thrust collar is another trick to keep the tube from spinning. Knurling creates additional friction to keep the collar from spinning.