We have invented a Premium Connection Insert for our collars that will protect the ends of the pipe and the inside of the collar from corrosion and electrolysis.  No more threads breaking off due to corrosive material seeping in between the collar and the pipe. This life changing product now comes on all of our Fiber-Lined pipe. Below on the pictures you can see where the threads have been eaten off by the corrosion seeping through. Our Fiber-Lining has not been affected by the corrosion.