Q: hydrualic effects of right-angle bends in PVC water lines

I recently repaired a leak in my water service lateral (1" PVC to 3/4" copper). The fitting I replaced was hard to reach without digging a LOT more hole. I got the copper-to-PVC adapter in well enough, but it was damned hard to get the PVC pipes into the glued-up slip joint because there wasn't a lot of flex available.

I thought afterwards that I could have put a series of right-angle bends in the PVC pipe which would afford a lot more flexibility during the repair. Is there a reason NOT to do this? Would make for stress in the pipe? Any hydraulic effects?

THanks a heap,

-Zz

Reply to
Zz Yzx
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It adds "head" to the line. There are calculators that will tell you how much you add for each fitting at a given flow rate and pipe size. Short answer, reduced flow.

Reply to
gfretwell

that would be fine, but you could also use a slip type compression fitting.

s

Reply to
S. Barker

PVC Dressler coupling? I wouldn't use one in buried service. I used to irrigate from the creek and used one as the disconnect to remove the pump at the end of the season. That thing coldformed the PVC pipe reducing it in size by at least a 1/4" in a couple years. Of course the effect was probably due to the repeated remove/replace but still...

Harry K

Reply to
Harry K

Maybe you wouldn't but irrigation companies use them daily in buried applications. It's the only sensible way to repair.

s

PVC Dressler coupling? I wouldn't use one in buried service. I used to irrigate from the creek and used one as the disconnect to remove the pump at the end of the season. That thing coldformed the PVC pipe reducing it in size by at least a 1/4" in a couple years. Of course the effect was probably due to the repeated remove/replace but still...

Harry K

Reply to
S. Barker

You could have used a repair coupling. With PVC, you have to be fast, but it works with less digging.

Don't have a repair coupling? Take a standard coupling and cut out the rib in the center with a hot knife. Slide it onto one side of the cut, align the other pipe and start the coupling back onto the second one. Apply cement and slide the coupling to where it is centered on the cut.

Done.

Reply to
Robert Allison

Yeah, and I've had to dig them up and effect a proper repair. Perhaps because of the cold forming of some component, but for whatever reason they never stay 100% water tight. Roots will find their way to those drops of water. The roots force around the gasket and then you have a significant leak.

Dresslers are seldom if ever appropriate for buried irrigation service. Use a real repair coupling and proper PVC glue and all will be well. Or if you have to, hollow out a normal coupling to make your own repair coupling. Just don't use a dressler.

sdb

Reply to
sylvan butler

I use the rule of thumb that a 90 is like adding about 2 feet of pipe but it depends on pipe size.

Here is a chart that gives "effective added length" for some typical fittings by pipe size.

I was surprised to see that my "rule of thumb" was only moderately accurate for pipes 1" or smaller. :(

Fittings for large pipes add much more "effective length"

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cheers Bob

Reply to
BobK207

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