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<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">It seems to me that I read somewhere that a curved pipe will reduce pressure because of the constent friction on the outside surface of the pipe. It doesn't seem to me that this would be any worse then the loss associated with a 90 degree elbow.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

I believe that you are right on both counts.

The basic laws of physics include the fact that an object will travel in a strait line unless a force is applied to it. In this case, the walls of the pipe will apply some sort of force, and this force will result in some sort of pressure loss.

As for will the curve reduce pressure losses, here's two examples of how to dodge an object by 10'. In both examples, we'll start 10' before the object and end 10' after the object.

Example #1 (90 degree turns): Go 10' to obstical, turn 90, go 10' and turn 90 to get beside object, go 10 to pass object and turn 90 back towards original line, go 10' to get to original line, turn 90 back onto the original course, go 10'. That's a total of 50' of pipe and 360 degrees of turn.

Example #2 (45 degree turns): At the starting point 10' before the object, turn 45. Go strait for 14' to get beside the object. Turn 45 and travel 10' beside the object, turn 45 towards original line, go 14', turn 45 back onto original course (you're already at that spot 10' past the object). That's a total of 38' of pipe and 180 degrees of turn.

So if you try the same thing with gradual turns, your losses should be even less.

Not at all......we pull are pipe over turns all the time, because its too many fittings that you loose pressure due to friction,,,,,be sure to use RVLI's advice and dont put the pipe through sharp turns because the pipe will bed in half.....good luck!!

Thanks
Ray
Rays Above and Beyond Automatic Lawn Sprinklers

Sure you can pull pipe in a curve but be sure it is gradual so you don't kink the pipe. I don't pull PVC to a bend, just 90 it.

Every sample layout that I have seen in all of the "How-to" books show all of the pipe pulled in straight lines with 90 degree corners.

I will be using 1" poly pipe and was wodering what effect if any having some curves will have. I am not talking about major zig-zag type curves, just going around tree trunks and around the end of houses.

It seems to me that I read somewhere that a curved pipe will reduce pressure because of the constent friction on the outside surface of the pipe. It doesn't seem to me that this would be any worse then the loss associated with a 90 degree elbow.