Leaking underground 2" PVC water line

[Briggs2513]

All,

Though I have used this forum in the past this is the first time I have posted anything, all the other forums I have searched for information have been spot on but I just can’t seem to find anything specific on this issue.
I recently installed 634’ of 2” schedule 40 pvc bell end pipe from my water meter to my first hydrant, later I will branch off to get water to shop and house. I live in central Kansas and saw that my minimum frost line depth was 28” – 32”, I trenched about 36” – 40” the entire way. A little deeper where I crossed the creek. Then I back filled the line all except the first piece and last which is where I think I went wrong…. After the city installed my meter with ¾” line coming out I tied in the 2” line.
I opened the hydrant and cracked the valve at the water meter and waited until the water was running out the hose connected to the hydrant. Est. time 15 min. After that I left the hydrant on and slowly turned the valve on at the meter. As soon as I opened the valve all the way the first bell joint downstream of the hydrant came apart.
I dug down so I could get to the connection, cleaned, regreased the fitting, and put the line back together. After the line was back together I back filled the trench to hold the pipe in place so it would not slip out. Then following the same procedure I filled the line again. Now with water running out of the hydrant and the valve open all the way at the meter I slowly shut the hydrant off and turned it on several times. After it seemed I kept getting the same pressure I left it shut and walked up to the meter to verify no leaks. When I got to the meter there was water filling the trenched hole.
I shut off the valve at the meter and dug to the first fitting off the meter. This joint did not slip apart so I went to the meter and turned on the valve but now the joint was leaking around the pipe like there was a bad seal. I turned water off and cut in a coupler which I glued. After repairing this joint I filled back in the trench around the pipe I dug up. I then opened the meter valve ¼ of the way with the hydrant open until all of the air was out of the line. Once all of the air was out of the line I turned the meter on all the way again. Both of the fixes worked and did not show any signs of leaking but the pressure is really low on the hose and when I shut the hydrant off the meter is still running pretty fast.
Now I am looking at digging up each one of the fittings and replacing it with a slip fix coupler….. 30 joints, and the slip fix couplers aren’t cheap!
Does anyone know what I did wrong or if there is a better way to fix the issue? Should I dig up the line and go with something else completely? I figured the slip pipe was the way to go as the water company uses it.
Additional info
I placed the bell end away from meter
The trench was 5” wide
I put all the joints together out of the trench then dropped it in
I greased the beveled end and the gasket inside the bell


Thanks
Brian

 

[Reach4]

I dug down so I could get to the connection, cleaned, regreased the fitting, and put the line back together.

What kind of pipe is that? I have not heard of that system.

 

[Sponsor]

 

[CountryBumkin]

I believe the OP is using the "standard" PVC pipe we are all familiar with (most don't call it bell-end pipe). http://www.commercial-industrial-supply.com/resource-center/what-is-bell-end-pipe/ However the reference to "greasing" the bell-end has me confused.

If you used the standard schedule 40 PVC pipe as shown in the link, and glued (not greased) the connections, were the pipe ends cleaned with "PVC primer" before gluing? If you skipped that step, it might explain why it came apart.

 

[Briggs2513]

What kind of pipe is that? I have not heard of that system.

2" bell end pipe, it is schedule 40 PVC the female bell end has a gasket in it and the male in is beveled to accept the pipe. You must grease the connections to fit them together.

 

[Briggs2513]

http://www.nationalpipe.com/pdf_files/New Installation Guide for Pressure.pdf

here is a link for the type of pipe, this talkes about larger diameter than I used but same style.

 

[Reach4]

http://www.northernpipe.com/downloads/IPSPressurePipe.pdf lists ASTM D-2241 GASKETED IPS PRESSURE PIPE | CELL CLASSIFICATION 12454

New to me. I presume you are using silicone grease for the gaskets. What keeps them from separating under pressure?

Are you using SDR-26 (160 PSI) or SDR-21 (200 PSI)?

 

[Briggs2513]

Another pipe link
http://www.northernpipe.com/pvcProducts/index.html

Grease
http://www.oatey.com/products/oils-lubricants-and-hand-cleaners/lubricants/pipegasket-lube

 

[Reach4]

At 80 PSI, I figure there will be 354 pounds trying to separate a joint.

 

[Briggs2513]

I was assuming the back fill was what helped keep it together but apparently not. Looks like I was told to use the wrong product I guess.

Nothing like a $400 material mistake and a weekend of trenching........

 

[Flapper]

Why not just solvent weld pipe? It would probably be a lot more reliable than that weird gasket seal stuff.

 

[Flapper]

At 80 PSI, I figure there will be 354 pounds trying to separate a joint.

No I think the actual force on the fitting is a lot less than the water pressure, not more.

 

[Briggs2513]

I can solvent weld the pipe the only issue will be if I have a steady enough hand in the back hoe to dig up the line without breaking anything..... Really thought I was doing the right thing.

 

[Reach4]

I wonder if you were to encase the first joint in place with concrete to keep it locked in place and concreted every 100 feet... Just guessing. I have not laid underground pressure pipe. I guess I would have thought the backfill would keep things anchored also, but I think your unintended experiment would say that is not enough. Maybe pound rebar down near the joints before pouring the concrete collar. Don't presume this is a good idea. I am just thinking, and I may be missing something.

Flapper, the force will be the area times the pressure. So that will be (pounds/square_inch) * square_inches. I figure OD is 2.375 inches, so the area is 4.43 square_inches. I think the OD is the right number to use.

I am suspecting that the grease may keep glue from working on the existing pieces. Again, I am just guessing.

 

[CountryBumkin]

I looked at the link you (OP) provided to the product. It is designed for 160psi, 200, or 250psi. So the pipe and attachment method works (with proper assembly). In the assembly instructions it states that there are reference marks that indicate the pipe is inserted far enough into the mating pipe to lock. I would guess that the problem came from moving the assembled pipe from ground level to into the trench.

Sorry that it didn't work out. Hopefully just a minor change in your installation technique is all that is needed.

I think if I was to do this job for myself I would lean toward getting a large (650ft) "roll" of 2" NSF poly (HDPE) tubing so there would no connections underground (or as few as possible). It's not cheap (at $1.38 ft plus shipping) but it's still not too bad. http://keithspecialty.com/water.line.pe.htm

 

[Reach4]

In the assembly instructions it states that there are reference marks that indicate the pipe is inserted far enough into the mating pipe to lock. I would guess that the problem came from moving the assembled pipe from ground level to into the trench.

OK... I missed the locking thing, and still think there is significant doubt. I think the locking referred to is the gasket being locked in place -- not the two pieces of pipe. In the attached snip, I see what I thought could have indicated barb that could have been the locking mechanism to keep the pieces from separating. EXCEPT that the inserting piece can be cut to length, so no barb. What would lock this in place, other than the fill?

 

[CountryBumkin]

That's a good question.

 

[MKS]

I have seen larger versions of this in some municipal work.
This is from the testing link at bottom of page.

1. The testing connection location should be at the lowest point of the line to be tested.
2. Be sure all blocking is in place (if concrete is used it must be cured to the necessary strength to withstand the pressure).
3. Pipe must be back-filled properly before testing.

So there maybe hope.

 

[hj]

I have installed thousands of feet of bell and spigot gasketed piping without them coming apart or leaking. You do have to secure any turns and the ends of the pipe so it cannot push out of the sockets.

 

[Briggs2513]

I only had a 5" trench and did not have and 45 or 90 degree turnes, I just made long turns with the pipe since it was flexable. Nothing drastic. I pushed dirt back in down the trench but did not pack it by any means since it was only 5" wide. Do you think that was my issue? If so do you think I can dig up sections every 40 - 60 feet and push the pipe back together? Then at each of those connections back fill and pack the soil?

 

[hj]

The pipe could not "come apart" in a 5" trench.