When we attached the copper piping to the new dishwasher connector via a compression fitting, the pipe slips out of the end despite plumbers tape and tightening the bolt from the pipe to the compression fitting. Should there be something, like a lip, on the copper pipe to catch the bolt and prevent the pipe from slipping out of the fitting?
A bolt in a compression fitting? Do you mean a nut? There should also be a slip ring called a ferrule, that goes over the end of the pipe after you slide the nut on. Then the pipe goes into the fitting, and the nut tightens down over ferrule and helps keep the pipe inside the fitting.
Based on what you have described, it seems like you may be missing a part called Ferrel. It has a end that is tapered towards the copper pipe and the other end is usually a little thicker. The way you would use this is first you would slide the threaded nut into the copper pipe, followed by the ferell, with the tapered end facing the end of the pipe that will be going into the dishwasher. Then you insert the copper pipe into the dishwasher, slide the ferell into the dieshwasher as far as it goes and then slide the nut and begin to tighten that with finger first. Finally use the wrench and make sure to go at least half a turn more than when you feel that the end of the ferrel is in contact with the nut. What this does it presses the ferel into the copper pipe forming a compression into the copperpipe that prevents the pipe from sliding out as well as makes a water tight seal. Should you have any leaks, give it another quarter to half turn until the leak stops. if you make it too tight, there is a chance that the ferel will cut into the copper pipe, so take it a little slow if this is your first time.
Slide the nut over the end of the copper pipe. Slide the ferrol, the compression ring, over the end of the pipe. Insert the end of the pipe into the dishwasher's water intake port until the end of the pipe touches the port's backstop. Hand tighten the nut. Place one wrench on the port and a second wrench on the nut. Tighten the nut while keeping the dishwasher's fitting still. Do not use plumber's tape on a compression fitting.
