Suggested pipe for lift station outlet line

[Ace Sewer]

Duplex, 8yr old, two separate systems, one for each side of duplex. Each side has a nice deep big pit outside with a manhole cover, single pupms, not grinders, pumps have not yet been a root cause problem. 4" pvc gravities into pits. 2" pvc sch 40 outlet lines (separate lines for each system) about 200' with about 30' of elevation to push up to city main. 2" pvc was put in with dwv fittings, which may be part of the problem as not pressure rated, although I don't think we're seeing more than 16-20 psi (thats all the pumps are rated to make). Both lines are separted beneath a driveway, plugged with gravel, and have multiple fernco repairs from previous separations. History is that every couple years something pulls apart again and gets dug up and jetted out and fernco'ed.

Owner has signed up to have it repaired once and for all. The pipes run up a steep slope, and I think it is shifting, either from groundwater or sliding down the slope or both. Worried that replacing with sch80 and pressure fittings will just create a stronger but still ridgid and brittle system that will pull apart as slope shifts. Considering something flexible...the corrugated flexible stuff used in hot tubs, or the 'polycore' blue stuff they are using for water lines to houses now in lieu of soft copper, or someone has recommended something called 'cts'.

We are going to pull out two boulder retaining walls and dig a deep trench (freezing is a problem here) on a very steep slope to do this and I don't want to do it twice.

Any thoughts?

[drtyhands]

Fused Joint High Density Polyethyline

How have you been since the Roundup?

[drtyhands]

Is it the expansion/contraction factor that keeps popping this thing?

[Ace Sewer]

Just keepin' the poop movin':p

[drtyhands]

We are only allowed to run 2" 85" horizontal on drainage.Are you sure it doesn't "bump-up"?

Oops,looks like the whole thing could be uphill.They would have to get that whole run moving.Those fittings aren't designed for that with there meesly 3/4" glued sockets.You're right.

[Ace Sewer]

Is it the expansion/contraction factor that keeps popping this thing?

I don't really know; it's the first I've been involved with it. I was called because they thought they needed a pump. found the pump spinning, and moving water slowly, and a little steam coming out under the drive... camera and find rocks in line, jet them out and camera and find a separation, dig it and repair and camera again... there are like 6 fernco's in one line, haven't camera'ed the other but it's pump kicked on and filled my hole... dug to it have a 45 broken. The drive has been a leachfield for a while.

The drive has a settled spot in it, and the tops of the blouders in one wall are all covered with dirt/dried mud, and the h o tells me the pipes have been repaired several times in the past.... I kind of think the drive is sliding ever so slowly down the hill and taking the pipes with it.

[Ace Sewer]

We are only allowed to run 2" 85" horizontal on drainage.Are you sure it doesn't "bump-up"?

Oops,looks like the whole thing could be uphill.They would have to get that whole run moving.Those fittings aren't designed for that with there meesly 3/4" glued sockets.You're right.

yes its all uphill... 150-200' run, maybe 30' of elevation gain... do you still recommend hdpe now knowing this? I'm thinking something with some more give to it so as things shift it can move a little w/o coming apart.

[drtyhands]

Not as much the pipe as movement issue.Somehow we need to come up with something to continuously stretch:confused:

At first I was going to suggest offsetting the line with some 1/8bends periodically.But with that you need to have a cleanout for every 135 degrees(every 3-45's).Sooner or later these are going to reach their max stretch and snap.

[Gene Bickford]

I'm not a "plumbing expert" but I would use one of those self contained grinder pump units and run a 200' roll of 2" hdpe poly pipe to the main.

[wrench spinner]

SCH 80!!! make sure that the pipe is backfilled in sand at least 6" above below and along side. also make sure that the pipe is properly compacted. Ill bet you 10 to 1 the problem is rooted in settling gimme the model nos. of the pumps and ill run a simulation to make sure that they are big enough as well as static head and length of run.

[wrench spinner]

also if the pipe is running really steep you can put in concrete collars around it. If you want you can upsize to 3" and run Ductile iron and be done with it forever although the pumps may not be sized right considering the DIP has a higher coefficient of friction.

[drtyhands]

also if the pipe is running really steep you can put in concrete collars around it. If you want you can upsize to 3" and run Ductile iron and be done with it forever although the pumps may not be sized right considering the DIP has a higher coefficient of friction.
I like the idea on the sand,actually logged on to suggest.Concrete collars?The I don't know the terminology,thrust blocks yes.Are the collars going to lock the pipe to soil,disturbed or undisturbed.What are they?The pipe is protected to allow for expansion inside the concrete?

[wrench spinner]

Adam, the concrete collars prevent the pipe from shifting, i specify wrapping the pipe with 1 layer of expansion joint then pouring the concrete around them, not quite thrust blocks but the same principal. We require concrete collars when the slope is greater than say 20%, which is pretty da&* steep

[MrsSeatDown]

We are only allowed to run 2" 85" horizontal on drainage.Are you sure it doesn't "bump-up"?



I am just a plumber's wife, but I think it is vent pipe you are talking about. Horizontal pipe is unlimited;)

[drtyhands]

I am just a plumber's wife, but I think it is vent pipe you are talking about. Horizontal pipe is unlimited;)

OOOPS.Guess I read it wrong.

THANKS JOEY:)

[JCsPlumbing]

I think the OP has problems with fittings and installation. I've run thousands of feet in similar situations. SCH.40 Bell End w/SCH.40 fittings. Primer and Glue. Hand cover and compact-especially at the turns-before final covering. Used the trenched material. Mostly NC red dirt/clay. No callbacks.

I understand the sand & concrete but it might be overkill.

No PE ever on a sewer pump we've installed.

Once again, No Callbacks. :D:D:D

J.C.

[PLUMBER RICK]

i know that hdpe sdr17 pipe is by far the most forgiving pipe out there.

what other pipe can you hit with a sledge hammer and have it bounce back? there is a reason why it's used in trenchless pipe bursting and slipling of waste and water mains.

i was under the impression that commercial sewer ejectors required 3'' pumps and discharge? upc 710.3.3

rick.

[drtyhands]

I think the OP has problems with fittings and installation. I've run thousands of feet in similar situations. SCH.40 Bell End w/SCH.40 fittings. Primer and Glue. Hand cover and compact-especially at the turns-before final covering. Used the trenched material. Mostly NC red dirt/clay. No callbacks.

I understand the sand & concrete but it might be overkill.

No PE ever on a sewer pump we've installed.

Once again, No Callbacks. :D:D:D

J.C.So your using pressure water fittimgs?

[wrench spinner]

I said sand because the dirt here is pretty much rock.... lots of angular stuff that wears through plastic pipe fast, particularly in a force main application. The concrete is most likely unneccessary but it is a common practice that i thought mcould be relevant. I have never used PE for a lift station i dont feel as though it is rigid enough i agree it is strong and durable, I may possibly explore its use ouside of the pump pit but inside the pump pit i feel as though a ridgid pipe would work better such as sch 80.

[wrench spinner]

So your using pressure water fittimgs?

Yes pressure fittings for forcemains!

[toolaholic]

One more thought,How about bringing in[ A geo tech] soils Eng to do a written report on the
site. As a Ca. Gen. We use them a lot,have to!

[toolaholic]

"Spotting a slide." Here in E .Quake Co. I do a lot of hillside retaining walls.Soils Eng. are great teachers. Many times ,I point out to homeowners Their hill is sliding. They do on to tell Me They've lived there 30 years and never had movement. Look for this above the Condos.
Trees at the base rotate at an angle out,and down hill. The sun,in time,straightens the new
growth Vert. Now You have a sweep in the trunk. Once It's pointed out to You,You'll pick up old slides all over. This is the 1st thing Soil Eng. look at on Our Hill sites before they do the drill samples. I think the West Coast Guys will enjoy this info. Marin Co." Where Your house May come down the hill to great You, when You come home" Tool

[Ace Sewer]

SCH 80!!! make sure that the pipe is backfilled in sand at least 6" above below and along side. also make sure that the pipe is properly compacted. Ill bet you 10 to 1 the problem is rooted in settling gimme the model nos. of the pumps and ill run a simulation to make sure that they are big enough as well as static head and length of run.

thanks, but not neccesary; bandaided one line and put a sump pump in the other pit to transfer to the pit for the bandaided line; pump is pushing it where it needs to go now that it has a path to push thru.

still have the original question on what to replace it with. I'm wary of any ridgid pipe in this application; sch 80 and pressure fittings would no doubt be better, but I know the excavator who did the initial installation and trust it was properly compacted. I know it was bedded in 3/8 gravel as I have dug thru the bedding to get to the pipe to put the bandaid in place. This spot was a previous repair with a fernco that pulled off. there was about a 6" gap between the ends of the pipes it used to connect. I have to assume it pulled down the hill. I'm thinking a continuous piece of something w/o fittings to fail....HDPE?

Homeowner/builder has electrical background, wants to sleeve it in 4" or 6" of something called 'smurf' electricians use for conduit. I'm thinking the sleeve concept might not be bad as I can run a piece of heat tape in it as well, and can replace it when it goes bad, and the earth and or sleeve might be able to move w/o disturbing my line... thoughts?

[JCsPlumbing]

i know that hdpe sdr17 pipe is by far the most forgiving pipe out there.

what other pipe can you hit with a sledge hammer and have it bounce back? there is a reason why it's used in trenchless pipe bursting and slipling of waste and water mains.

i was under the impression that commercial sewer ejectors required 3'' pumps and discharge? upc 710.3.3

rick.

Do you put in sewer ejectors in Cali. with sdr17? With the no-hub bands on hard turns?

We're IPC here. Once again, I have no idea why we can't have 1 code. :rolleyes: Everything from acidic soils, freezing, earthquake strapping etc. could easily be included. Maybe some people have more viscous water. :D

It doesn't make sense to require a 3" pump and discharge $$$$$$$$ in all commercial applications. I know code is code. But what if I have a warehouse with 1 lav. & toilet with whatever kind of gravity connection 50' away? Some of the packaged systems$ pump manufactuers produce are even overqualified to handle this. :confused:

J.C.

[JCsPlumbing]

Just looked where you are again Ace. Do you think it could be experiencing frost heaving?

J.C.

[wrench spinner]

municipal systems whether it be for one house or 2000 require a 4" discharge with a convential pumps or 3" with grinder in a few states, nostly north east, our guidelines are the "ten-states standards" (NY, CT, MA, OH, MI, Wisconsin, RI, NH, VT, ME) But that is just public systems, I am looking into Vacuum systems for a project out in California, has anyone had any experience with these?

[Chauncey]

SDR 21 Goes together like SDR 35 and is designed to be used on force mains. I have put in a few miles of this stuff here in NY never had a problem with any pipes coming apart. Don't forget to tape a 12 ga tracer wire to the top of it with duct tape before you cover it up, leave the end by the pump station above grade to connect locator too.

http://www.ridgidforum.com/forum/showthread.php?p=126197

[Ace Sewer]

The end of the story, for now...

Dug the thing up and replaced it with "purecore", stout blue plastic stuff with some flex to it that is being used to run water lines to houses here lately... that is usually done in 1 1/4", found it in 2" in 200' rolls and used that.

[drtyhands]

What kind of plastic is it?
How do they normally connect it?Heat fusion?Or is it like Pex with their barbs,rings or whatever they use?

What did you end up using for backfill to help your pipe not dislocate from the ground settle?

[Ace Sewer]

What kind of plastic is it?
How do they normally connect it?Heat fusion?Or is it like Pex with their barbs,rings or whatever they use?

What did you end up using for backfill to help your pipe not dislocate from the ground settle?


It's this stuff... http://www.uspolycompany.com/index.php?ID=685

Came in a 200' roll so I didn't have to have any joints, they have stiffeners which go inside the ends and two piece screw together fittings to terminate the ends in male pipe threads. I assume if you needed more than 200' you'd either have to see about getting a longer roll or join it with fittings.

Bedded it in crusher fines. Pipe has some flex to it so I'm hoping it'll be free to move a little if it needs to.