Occasionally you see that type of light grey rigid conduit used outdoors in direct sunlight. Usually it's all bowed downwards in horizontal runs and cracked all over. Cable has to be UV resistant too but most people don't seem to care at all.
I don't think anyone used a bending spring here from the mid-70s onwards. They're still in manufacturer's catalogues but I haven't seen them for sale anywhere, only for copper plumbing pipes.
Ragner,
We have a hole in the ozone layer down here that gets bigger or smaller with the change in seasons, our UV levels down here in the summer, with no cloud cover can be really horrendous on PVC, other wiring materials and people if they aren't careful.
All PVC that we use here needs to be "UV-stabilised" or it won't last more than a couple of years.
Bending springs are what I was bought up with here, one of the first jobs you'll be given here as an apprentice, is to bend up some crazy looking off-set, with measurements from your boss and by God, you'd better have it right the first time!
Bear in mind Ragner, all PVC bending springs are internal springs that go inside the conduit, you don't need any heat (unless it's the middle of winter), just rub it with your hand and bend the conduit under your knee-cap, easy as.
Anything over 1 1/4 (32mm), I just prefer to use pre-formed 45 and 90° bends/elbows, that's what they make them for.
Bending springs for soft-copper tubing are always external springs, I used to do a bit of refrigeration stuff a few years back, I've forgotten most of it these days, but this is mainly to support the inner radius of the bend to prevent it from kinking over or rippling as the bend is done.
