What can I do when putting in a coupling but there is not enough flex in the water pipe to get both sides of the coupling on?
If you're dealing with copper, you will find two types of couplings. One has a stop in the center and one without. What you need in this case is the type without a stop. Without a stop, you can slip the coupling over the entire end of one pipe, and then slip it over the end of the other pipe.
With Stop (notice the dimple in the center)
Often a union allows you to deflect each end of the pipe enough to place the adapter on that side. Then the amount of flex needed to align those sides is less than that needed for a standard coupler.
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