Pipe coupler installation
Pipe coupler installation
(OP)
I am looking at a water delivery pipe failure and need a little help. The pipe is a 2" I.D. steel/iron line from the main and the failure occurred at a coupler that was used above a new shutoff valve. The coupler is a friction fit (non-threaded) where it attaches to the distribution line that runs through the building. The pipe and coupler are out of alignment by approximately 3.3 degrees. Visually it looks like the misalignment is worse. I cannot seem to find information for these fittings regarding maximum allowable axial misalignment either as industry standards, specific product standards, or code requirement. I need to answer the question "was the installation faulty?" and if so need to be able to point to the standard/regulation that was violated. Any help or advice would be greatly appreciated.
Thanks,
Sennafan
Thanks,
Sennafan





RE: Pipe coupler installation
Please provide a manufacturer, part number, or a detailed description, or a photograph. Thanks.
Mike Halloran
Pembroke Pines, FL, USA
RE: Pipe coupler installation
Was this in St. Louis??
RE: Pipe coupler installation
RE: Pipe coupler installation
RE: Pipe coupler installation
Notice how the body is belled out, to allow clearance for misaligned pipe ends. I think the packing inside the packing nut on the end will distort enough to seal any pipe that you can get into the body.
If the contract doesn't include the word "workmanlike" or something like that, and the joint is not leaking, I don't see a basis for rejection.
... against current practice in the USA. My father wouldn't have tolerated it as a customer, nor submitted it as a workman. Today, if you complain about something like that, you'll get a whole lot of attitude, and a repair that's even uglier and will leak sooner.
Mike Halloran
Pembroke Pines, FL, USA
RE: Pipe coupler installation
I do not know if this will help, but....
For larger pipelines (water mains) there exists sliding dismantling or connection pieces of steel (two concentric tubes) or nodular iron wich can be tightened both for the concentric part and the grip around the pipe-ends they connect to.
For theese products there exists some guidelines on how much they can be out of alignment, but mostly the tolerences are not given or exists, describing mounting to be concentric with the original pipeline.
Theese types will normally tolerate (personal experience, no producer backed information) up to 2-5 (up to 7?) degrees skew. Two points: this will be less tolerable for a short length one-piece item. The dismantling pieces will be in two parts and can also be thightened at ends to avoid leakage.
You have a one-piece short item, no mechanical thightening possibillities.
Leaking is obviously pointing out that something is wrong. The leak could be caused by one or several causes in combination:
-Unsuited product, material and fastening/mounting methode
-Non-coaxial/linear mounting
-False mounting else (what do mounting instructions say- allowable minimum overlapping?)
-Dirt or uneven pipe-ends (left materialparts from cutting ends?)
-Lacking of clamping of pipeline, pipeline moving by temerature, shocks from waterhammer when closing valve, mechanical thrust when closing valve.
- Overpressure (by testing?) or general pressure disforming the plastic material
..and perhaps some others.
The conclusion is that all above goes back to company responsible for mounting the installation. (Perhaps exception: if someone else has selected all material components and set measures for mounting of all components and clampings on pipeline, but again a good installation company should have reacted.)
I would not have used a plastic component at this point, and clamping around valve and on pipeline seems unsatisfactory.
RE: Pipe coupler installation
Thanks again,
Sennafan
RE: Pipe coupler installation
I don't know what a code might say, but pipes joined with couplings like that _must_ be anchored, because hydrostatic pressure can separate the joints, just like the rod oozing out of a hydraulic cylinder.
Roughly similar joints used in boats optionally come with metallic teeth embedded in the rubber packing to grip the pipe for exactly that reason.
The force exerted is supply pressure times the gross area of the pipe; no external vibration needed.
Mike Halloran
Pembroke Pines, FL, USA
RE: Pipe coupler installation
Any idea if there is a specific code section (mechanical or plumbing) that requires anchorage to resist the hydrostatic pressure? From what I can see the plumber did anchor the end of the pipe that slipped, just did not understand that wall plate-to-stud nailing is not really effective in tension.
RE: Pipe coupler installation
Just seem coincidental??
RE: Pipe coupler installation
People have been saying the federal courts are "all wet" for years. Sounds like the plumber's defence ought to be "what's changed?".
My case is a 2" line in an office-warehouse that reportedly flooded the building to a depth of around 3" when the first guy in discovered it at 5:30 AM.
I started my career in St. Louis - 2 years with IL Dept of Mines and Minerals, then five years at two different small consulting firms before moving to the north-west in 89. We may have some mutual aquaintences if you're career is in buildings.
RE: Pipe coupler installation
Ring a bell?
RE: Pipe coupler installation
Carr and Associates and Leonard Weintraub and Associates are the two consulting firms I worked for. Both very good guys to work for in different ways and both had good staff to work with and learn from.
RE: Pipe coupler installation
RE: Pipe coupler installation