If it’s either the 16mm or the 25mm PolyRail, there might come a time when you have to make a repair in the line.
YES this can be done.
Dramm has barbed connectors that will fit inside the Polypipe. Pull Polypipe from channel; give yourself some room to work with, about 12”-24” on either side of repair. Cut Polypipe and insert the barbed coupling to re-join both ends, use a gear clamp on barbs (be sure knuckle is downward) and re-install into rail. The repair might be slightly bigger than the channel; there is some give where you might see channel expand over repair when pushing back into place.