The HAM-LET Stop Collar is designed to be used to install HAM-LET Let-Lok Double Ferrule Fittings into areas which are difficult to visually check/is easily accessible with an inspection gauge.
The Stop Collar is designed so that when tightening the nut, once 1-1/4 turns are achieved the nut will not tighten any further. The Stop Collar is also knurled on the outside diameter to enable you to feel with your finger if the stop collar can rotate then the fitting is not sufficiently tightened. Once you can feel the Stop Collar will no longer rotate this indicates the fitting is correctly assembled.
Below are the installation step by step instructions to make up the fitting using the stop collar:
The HAM-LET Stop Collar
Remove the nut and ferrules from the fitting
Insert the stop collar onto the fitting body
Reassemble the front ferrule
Reassemble the back ferrule
Reassemble the nut
Insert the tube into the fitting up to the shoulder (as far in as the tube will go)
Make sure the nut is finger tight. The stop collar will rotate freely
Tighten the nut until you are unable to tighten any further
Once you are unable to tighten the nut any further the stop collar will no longer rotate freely (feel with finger)
At this stage it is guaranteed the fitting is assembled correctly