As carry-on luggage
Most airlines have rules that limit the size of carry-on luggage (mostly so that it fits under the seat in front of you or in the overhead luggage bins). To make it easier to check, they usually state the rules as maximum length, width, height, rather than the sum of the 3 (as is more often the case for checked luggage).
For instance, Lufthansa has a limit of 55 x 40 x 23 cm.
Aeroflot has limit of 55 x 40 x 25 cm.
Such limits are often waived for musical instruments and a few other items (under specific conditions), but I doubt a PVC pipe qualifies.
As checked luggage
Here the limitations is more often the sum of all three dimensions. For instance, both Lufthansa and Aeroflot have a limit of 158 cm.
If precisely 5 foot long (152.4 cm), then it needs to be quite thin to fit within the limits.
Beyond that, there are special oversize luggage categories, but those come at a cost (often quite high, especially on international flights, and even more with several connections).
However, I’m not sure sending your PVC pipe as checked luggage is the best option if you want it to arrive in the same condition at your destination (i.e. neither bent, broken or scratched), and 2 transfers definitely won’t help.
So IMHO even if doable, it’s probably not a good idea.
However, I would be surprised if you couldn’t buy PVC pipe at your destination.