I made some PVC joints that will be buried, since they won't be easily accessible I would like to make sure they are perfect.

When I glued them I used primer and glue, but I had to "twist" the pipe a bit to fit the elbow (it was an "almost" 45° bend). Now, some 5 days later, it is holding well under full pressure and no water seems to be leaking anywhere, but because of the force fit on the elbow I'm still worried.

I think that if it is still holding so far it should hold for good, is it true?


I'm not sure I completely understand what you mean by "twist." You mention a 45 degree bend. Is that the bend of the elbow? Why was a "twist" required?

At any rate, if it is holding, it will probably be fine under static loads even if installation was not perfect. However, a bad joint will typically only reveal itself under more extreme dynamic loads. Pressure spikes typically occur due to air in the line or water hammer. An acceptance test generally requires applying 150% of design pressure to the line and checking for leaks (that is, hyrdostatic water pressure, not air pressure.... applying compressed air to the line could be quite dangerous if anything fails). I assume you have no way to do that.

So, the best you can hope for is that your installation was adequate and followed correct procedure. At a minimum that would involve, deburring and beveling the pipe edge, applying sufficient amounts of cement to the pipe and fitting, ensuring the pipe is seated completely and uniformly in the fitting (fusion of the pipe and fitting typically only occurs right at the tightest portion of the fitting.... elsewhere, there is simply a mechanical bond that is weaker).

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  • Twist is not the proper term, I used a 45° elbow and the angle between the pipes where 43ish. So I had to use a bit of force to join then together. Also, I could not do the 1/4 recommed turn since the pipes where fixed on each end, so they were just pushed in. I know the fusion is just in tighest part, and since the pieces where a bit misaligned, this is the reason of my worry. – Luiz Borges Nov 7 '14 at 17:26
  • I see what you are saying. I think you rightly have some cause for concern. But without a static overpressure test, I don't know of any sure way to know whether the joint is sound. Maybe others do... For a cheap DIY test, you could always fill all the pipes with water, and then pressurize the system with compressed air to 1.5x working pressure. That would be less dangerous than using just air and it's easier to see leaking water. The water will absorb gas under pressure, however, so you may need to "top off" the pressure a few times to make sure pressure isn't dropping because of a leak. – bobfandango Nov 7 '14 at 21:11
  • I can't do such test. I did leave it under to the operating pressure for 5 days already and no leaks (I used a fine napkin to try to find droplets). I'm almost thinking of redoing, but without a way to fix the aligment by such small margim I'm not sure it is worth it. – Luiz Borges Nov 7 '14 at 22:04

For small adjustments you can soften the pipe with a hair dryer or heat gun. Experiment on an offcut because the difference between malleable and collapses is tiny. Once heated and allowed to cool it stays at the new shape without stress.

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