SEQUENCE FOR API CLAMP USING 4
Note: Washers must have
proper installation orientation, as shown above.
To assemble a Clamp on Hubs, follow the
Instructions on this web site.
Install Fluoropolymer coated
bolts, nuts and spherical load bearing washers.
After all nuts have
been run down by hand, start wrench tightening following the
sequence of the numbers indicated (marking the number on the
Clamp with a crayon aids in keeping track of the tightening
Because of the nature of the fit between Clamps and
Hubs, a considerable number of nut turns may occur before
achieving a significant percentage of recommended torque.
During all of the following steps, keep
the gap between Clamp halves even on both sides, with
nuts made up approximately the same amount on each end of the
First time around just snug the nuts with
a hand wrench.
Continue tightening the nuts, closing the Clamp
around the Hub evenly, until the space between the Hub neck
and Clamp bore becomes nearly equal.
Continue tightening to achieve approximately 25%
Tighten another round to approximately 50% of
Again to approximately 75% of recommended torque.
Again to 100% of recommended torque.
Repeat this process until nuts do not move
under 100% recommended torque.
If possible, re-torque after 24 hours.
Most of the bolt preload loss occurs
within 24 hours after first tightening.