Lawn Care Forum banner

Compresson Fitting vs. Slip Fix

20K views 33 replies 12 participants last post by  Mike Leary 
#1 ·
OK, my son and I are having an argument on which is best to use on a 2" PVC mainline. He says, a slip fix is fine if your connect it fully extended. I say for this repair you should only use a compression fitting. What say you???, and why??? Thanks!
 
#2 ·
You'll get arguments both ways as this has been hotly debated here before. Personally, we never install Slip Fixes on pressure lines (but use them all the time on lateral lines) and stick with either compression couplers or Dresser couplings depending on line size. I've replaced way too many Slip Fixes installed by our district plumbers in the past when they were initially maintaining our irrigation systems years ago.
 
#5 ·
We use short pipe with bell end and a coupling.Once you start glueing no stopping.
Do not like this method. Involves going all the way down and pulling the bell forward which I think destroys the integrity of the glue joint. I would use slipfixes before this method. 4 ells is the best solution in my opinion.
 
#9 ·
Ive used both but prefer the comp. fittings, the only downside to them on larger piping is that they need to be thrust blocked so they don't blow off or get pushed off the spot they are repairing, wood is no good because eventually it may rot and allow the comp. fitting to move off of its spot.
 
#10 ·
Meister, 4 elbows is going to hurt pressure. This is a main that feeds a ton of distant laterals on a high rise condo.
What is the pressure like now? I guess the best solution would be Purps but if you use a comp fitting let me throw a thought out there for the skeet shooters here to fire at. Assuming this is a 2" pipe cracked or whatever and the nearest elbows and/or tees are not known. Take 2 2" crosses, glue in 2' of pipe on on opposite ends with caps glued on basically making it a cross turned into a coupling. glue those on each side of the coupling repair about 3-4' away. Then pour a bag of concrete around each cross/ coupling with the comp coupling in between. This would certainly prevent any shifting either way on the pipe. I've seen pipe shift inside concrete so the cross would add extra strength.

Good idea or bad idea? Better way?
 
#13 ·
Or perhaps you could use a couple of Wyes (Spears #P600-020) with a 1/16 street bends (Spears #P326-020) once you cut out the damaged area.
Some alternate Spears Part numbers would be Wye #475-020 and possibly a 22 1/2 degree street elbow #442-020 or whatever it takes to get the repair section coming off wye parallel with the existing pipe.

First post part numbers are listed in their DWV fittings, the above numbers in their SCH40 PVC fittings.
 
#14 ·
Some alternate Spears Part numbers would be Wye #475-020 and possibly a 22 1/2 degree street elbow #442-020 or whatever it takes to get the repair section coming off wye parallel with the existing pipe.

First post part numbers are listed in their DWV fittings, the above numbers in their SCH40 PVC fittings.
More words of wisdom from the human parts catalog.:laugh:
 
#23 ·
I don't like compression fittings on pressurized lines.The composition of the backfill material enters into it.

About 25 years ago we had a mainline out to a small apricot orchard that was 2" and was buried about 36" deep to give the tilling equipment plenty of room. A bad glue joint was replaced with compression fitting (sometimes called a "kubota"). The soil was a heavy clay and the swell and shrink from wetting and drying eventually allowed the fitting and pipe to shift and leak again. Granted this was unregulated pressure of about 120 PSI as I recall. Thrust blocks might have been a good idea if somebody had thought about it. The final repair we made used 4 ells.
 
#24 ·
The Spears SCH 40 DWV (fabricated fittings) through 12" are pressure rated to 130 PSI.

Check out section 6.4:

http://www.spearsmfg.com/prod_dimensions_spec/FAB-7-0702_0807_web.pdf
This is true...but there is a huge difference between 'Fabricated' fittings and 'DWV Molded' fittings. The molded are for "Drain, Waste & Vent" non pressure applications. Section 6.4 also says:

DWV Fittings - NPR
WYE, Combo WYE, etc. DWV - NPR

And yes I have seen what a 4" DWV ell looks like when it is subjected to 120 psi on a golf course. It makes a helluva hole when it comes apart!
 
#26 ·
:laugh: :laugh: :hammerhead:
Mike...The Chairman of the Greens committee called and said that I had made a faulty design and sold them defective fittings. (I was working for a supply house in So. Texas) They had put the system in themselves.
Drove the 100 miles -one way, to check out the problem. He took me over to a pile of pipe and fittings that they had taken out because of breaks.

I took one look at the fittings and told him that I hadn't sold the DWV fittings to him. He then remembered that they had messed up a few connections and had to cut them out. One of the members ran a hardware store and he brought them the needed fittings. Of course the only ones he had in 4" were DWV. Blew the end right out of the ells.

He apoligized and then took me to dinner at the Country Club. Rode in his restored '58 Vette convertible. Then we went a played a round of golf. All in all not a bad trip.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top