Plastic pipe for underground?

[hawkeye08]

On my freeze hydrants (faucets with valve underground and self draining standpipe), I use double street elbow in addition to the T, that gives me a place for movement if needed without breaking the T or the underground pipe... Most of the galvanized plumbing is coming from China and does not stand up like the older USA stuff. I have been told that if you can find USA galvanized, it will hold up better. I don't know if it was just talk or not, but I couldn't find any anyway.

 

[charlz]

Thanks!

I found a chart that relates pipe size/volume:
GPM/GPH Flow based on PVC Pipe Size, ie, How much water can flow through Sch 40 Pvc Pipe Size 1/2" 3/4" 1" 1.5" 2" 2.5" 3" 4" 6"

According to the chart, it looks like given ideal conditions a short 3/4" outlet pipe (rated 36gpm max, 23gpm preferred) would pass the full output of the well pump - whatever that is. Then size up from there considering friction loss due to length and fittings. So I don't need to go back to the 1.5" size that I'm replacing. Maybe 1.25" for the longer runs, so a big Rainbird sprinkler can have good volume out at the end of the line.

No you really want to be in the green range on the higher GPM side. If your pump is 10-15 GPM then you want to be on at least a 1" pipe. This is to keep the speed of the water down and avoid water hammer when opening/closing valves and the pump kicking on/off. Next is to look at pressure drop through your whole system which is what you looked at here:

The chart linked above also references a chart for length/loss that indicates the Rainbird 100 ft out would receive 10~20 psi less than at the well. This seems acceptable.

Often the cost of going the next size up pipe is minimal and then is already in place for any future expansion plans or if you upgrade your pump.

 

[boggen]

Thanks!

I found a chart that relates pipe size/volume:
GPM/GPH Flow based on PVC Pipe Size, ie, How much water can flow through Sch 40 Pvc Pipe Size 1/2" 3/4" 1" 1.5" 2" 2.5" 3" 4" 6"

According to the chart, it looks like given ideal conditions a short 3/4" outlet pipe (rated 36gpm max, 23gpm preferred) would pass the full output of the well pump - whatever that is. Then size up from there considering friction loss due to length and fittings. So I don't need to go back to the 1.5" size that I'm replacing. Maybe 1.25" for the longer runs, so a big Rainbird sprinkler can have good volume out at the end of the line.

The chart linked above also references a chart for length/loss that indicates the Rainbird 100 ft out would receive 10~20 psi less than at the well. This seems acceptable.

I like the idea of trenching with a ripper or potato plow. But where I need to make the first repairs, only my backhoe's boom can fit in there.

*arghs* i hate charts like that. they can easily mis lead someone to getting to small or to large of a pipe. "been there done that" it doesn't matter of pool, pond, well, or other, i simply hate charts found on the internet.

old calc i did up years back. to ball park things out for ponds for pipe sizing.
WorldWide Koi Club - Pipe Sizing ( advance velocity ) calc
entering in first 3 boxes...
50
50
200

entering in next row of boxes.
0.50, 0.75, 1.0, 1.25, 1.5, 2

clicking "calc" button

green P = pressurized flow of water. (example water coming from well pump)
green G = gravity flow of water. you pump water up to some tank up high on a hill. and letting water just empty out of a tank some place down the hill without use of a pump between tank and outlet for the water.

very bottom you can adjust min/max settings for P and G in how they show up for "green" in the chart.

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1" to 1.5" pipe size is what i would be looking at. based purely on velocity alone and inside diameter of pipes and fittings.

to figure things out better. it normally takes an excel sheet, and knowing all the lengths of hose and pipes, and were each fitting and type of fitting it is and the "actual" inside diameter of pipe/hose and/or fittings. we say 3/4" or 1" etc.. but actual inside diameter is less on pvc pipe, and can be mis leading on hoses pending if you look at outside daimeter vs inside diameter of the pipe. then calculating at different GPM (gallons per minute) or hour. and plotting results on the "pumps performance curve chart" to get a more accurate estimated flow rate you would get at any given outlet (faucet or like)

a pumps performance curve... the more the pump has to overcome in friction loss. the less GPM it will produce overall. the less friction loss a pump has to overcome the more GPM it will produce.

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it has been way to long since i had to figure the math out. and done forget, water hammering velocity, i think you want to stay below 15 feet per second, or is it 8 or 9 feet per second (F/S)
i want to say you want to stay above 4 feet per second velocity, to clear any sort of air bubbles that may happen within a line. or is it 7 feet per second?
ya don't take above numbers as fact. "memory is trashed" on all the fine detail specifics.

 

[clemsonfor]

black rolled pipe!!

 

[farmer2009]

Really need to figure out pump flow. My 2 horse power pump is on a 30 amp breaker and rated at 40 gpm. Also it's installed on a 2 inch line.

 

[charlz]

Really need to figure out pump flow. My 2 horse power pump is on a 30 amp breaker and rated at 40 gpm. Also it's installed on a 2 inch line.

I agree, probably best to do some GPM testing with a 5 gallon bucket and stop watch.

 

[boggen]

if you know the well driller, give them a call they are suppose to keep records. if anything pull the pump up out of the well and find the model / manufacture, and look up spec's online majority of manufactures have most of the info online now.

5 gallon bucket test is simple method. but make sure it is actually 5 gallons, and not 4.85 gallons or 4.68 gallons. and remember 5 gallon bucket test is a ball park figure.
also make sure you let the well tank "pressure tank" go down, say run water for 5 to 10 minutes fully open with OUT a garden hose nozzle on.

 

[California]

Ok, this pump is so old (1991) that its specs aren't listed online. According to the warranty doc I found in the barn, it is:

Goulds model 13EM10.

Closest match I can find in Goulds' online docs is GS series started in 2003:

Goulds model 13GS series specs:
GPM 4~20, HP 0.5~5, Best efficiency GPM: 13, GPM Discharge diameter 1.25".

And model 13GS10 is the 1 HP member of that series. So assuming their prefix and suffix #s from 2003 are consistent with earlier models, I have a pump rated less than 20 GPM. Maybe 10 GPM, interpolating 1 HP into the data above.

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Conclusion from all that: the pump output is 1.25" diameter, and 1.25" 200 psi HDPE pipe should be sufficient for the separate lines from the pumphouse to the house, barn (washing machine), and garden. The outlet for filling my watering trailer will be larger and will be at the pumphouse.

 

[farmer2009]

Call goulds customer support they should be able to tell you the specs. Maybe able to email them also

 

[California]

I'm still studying what I need for the project.

Here's a pdf showing HDPE is far more able to stand surges and water hammer compared to PVC pipe.

But I'm concerned by the comment above that gophers prefer HDPE over PVC. Has anyone experienced chewed pipes?

 

[daybreak1998]

I'm still studying what I need for the project.

Here's a pdf showing HDPE is far more able to stand surges and water hammer compared to PVC pipe.

But I'm concerned by the comment above that gophers prefer HDPE over PVC. Has anyone experienced chewed pipes?

Howdy,
I think you should go to the local supply store and look at the black plastic pipe (HDPE Pipe) You will want the higher PSI rating style, and after looking at it, you will realize that the stuff is tough. The same thing about thinking it would break if turning on a vertical hydrant, no, 1 inch black pipe, 210psi, will not just break.

Everytime you have a PVC pipe connection, is every place you can have a leak. (probably every 20 feet if you get that length pvc.)

 

[check]

I have 1.25 inch line that runs from the cottage downhill about 300 feet to the boathouse, then turns around and comes back uphill a little over 200 feet to a second cottage which is approximately 10 feet lower than the first cottage. So there is no uphill pumping and in fact we gain a little bit due to the second cottage being lower than the first.

We use well water that is pumped into the first cottage with a 10 gallon per minute pump, then runs through the UV/ filter system, then a bunch of half-inch pex line with several fittongs, until it exits the cottage on the other side, where is connected to the 1.25 inch black poly pipe that goes down to the second cottage.

Anyone see any problems with this? We seem to get plenty enough water flow and pressure at the second cottage.

 

[boggen]

I'm still studying what I need for the project.

Here's a pdf showing HDPE is far more able to stand surges and water hammer compared to PVC pipe.

But I'm concerned by the comment above that gophers prefer HDPE over PVC. Has anyone experienced chewed pipes?

as soon as i say i haven't, i will have problems! get the pipe in ground a couple feet or more. and you should be ok, and be at risk like everyone else is.

my worries would be pipe only being in ground a few inches, and being right in the roots of the yard/lawn, were grubs / worms and like would be, and the food source for the critters.

 

[boggen]

I have 1.25 inch line that runs from the cottage downhill about 300 feet to the boathouse, then turns around and comes back uphill a little over 200 feet to a second cottage which is approximately 10 feet lower than the first cottage. So there is no uphill pumping and in fact we gain a little bit due to the second cottage being lower than the first.

We use well water that is pumped into the first cottage with a 10 gallon per minute pump, then runs through the UV/ filter system, then a bunch of half-inch pex line with several fittongs, until it exits the cottage on the other side, where is connected to the 1.25 inch black poly pipe that goes down to the second cottage.

Anyone see any problems with this? We seem to get plenty enough water flow and pressure at the second cottage.

yes and no....

if it is just your family, and not renting or like the cottages no biggie. but if renting. i would most likely have an issue, with water pressure and GPM of water.

well with well pump -> cottage 1
cottage 1 -> check valve -> UV / Filter system -> well pressure tank -> TEE
TEE -> check valve -> pressure regulator -> to pipe work in cottage 1 (sinks and like).
TEE -> cottage 2
cottattage 2 -> well pressure tank -> check valve -> pressure regulator -> pipe work in cottage 2 (sinks and like)

above places a well tank at each cottage, to help with keeping water pressure up were it needs to be, and help some what with water hammering effect.
in cottage 1, skipping all the 1/2" pex and running 1.25" directly off of the UV/ filter system / well tank. and directly to cottage 2. you get away from extra pressure loss inside cottage 1 feeding cottage 2.

if cottage 2 turns on water and has it running for a couple minutes, and then someone turns on water in cottage 1, cottage 1 may not get any water what so ever, and possiblly get air sucked into the pipes, or a siphon happens and dirty nasty water gets sucked back into the drinking water lines. with pressure regulators and check valves. the issue goes away to a good extent. to point cottage 1 and cottage 2 regardless of who is using what water and amount, will still get some water with the pressure regulators. and check valves just keeps everything going correctly in case something happens.

 

[hslogger]

When I first showed up on my own place it had a few hundred feet of black poly pipe buried to code from a pond pump site to the garden and outbuildings. I kept thinking there was a leak. I found it, some mole, vole or gopher or mutant satanic creature had chewed through it. Oh boy I thought, I hope that doesn't happen again. Well it did, numerous times. I dug it out and replaced it with 2 inch PVC and it was the best investment I could have made. Years later, I added a quarter mile of PVC, to the system and tied it into other water sources. In western Oregon, critters WILL eat the poly pipe. It aint a question of if, but when. PVC thick walled pipe has never failed me underground. I wouldn't however, bury PVC valves. If you are going to bury valves or shut offs go brass or bronze. PVC valves can fail and you can't fix em. You have to cut them out and replace them. If you are going run the pipe over ground, I would paint the stuff to cut down on UV penetration. You could get Banjo fittings and use them on your PVC above ground and you could move or take the pipe down anytime with out damaging anything.

 

[hslogger]

andddd another thing. I know once in a while Napa Sonoma gets a nasty freeze, once in a blue moon. You will never regret buying USA made frost free hydrants. I have them all over the place and they are flawless. China ones not so. USA. When you install your hydrant or if you choose conventional riser and valve, use two street elbows between the upright pipe and the feed pipe. In other words do not install your up right directly into a Tee or elbow. If you don't know what a street elbow assembly set up is, ask or look on the net. Basically it is two, elbows that have screw threads, male and female. You screw those into the SCREW fitting on your supply pipe. This double street elbow set up will allow easier replacement if you have to, and it will take any stress you might put on the upright by hitting it or ground heaving.

 

[charlz]

PVC thick walled pipe has never failed me underground.

And just to note, he is referring to the schedule of the pipe (20,40,80)... you will see 'foam core' pvc that has a thick wall but it is NOT pressure rated so you do not want that stuff. Also, at the range someone ran schedule 20 for all the outside hydrants. Now when you go to work on the stuff or tap in it is like working with glass. Frustrating to be trying to cut the stuff with a saw and it just keeps cracking further and further back on the line. Schedule 20 is cheaper but I wouldn't use it after my experiences with it.

 

[ultrarunner]

So far I have used only copper L

Found a deal on 500' of soft copper L and bought it plus a couple 100 feet of 1" soft copper...

Hope is a one time project.

Now I have the area around the homestead done... I still need to address the mix of old galvanized and PVC with much of it surface run for 800'

Terrible gopher and ground squirrel problem here... so this why I went only copper so far.

As to pressure from the spring... it's 50 psi

Turn on one hose and it drops some... turn on two garden hoses and the flow is dramatically cut...

 

[California]

I still need to address the mix of old galvanized and PVC with much of it surface run for 800'
Terrible gopher and ground squirrel problem here... so this why I went only copper so far.

Gophers eat PVC as well as HDPE?

The gophers around here are so bad that .... Luther Burbank gave up and abandoned his experimental farm that was once near me.

(He started a new farm 10 miles East and donated the failed land to the cemetery district. True story.)


Maybe I should re-think this whole idea of plastic pipe. My North Bay and your East Bay terrior (fancy word) are approximately the same.

 

[lostcreekranch]

Try these for laying the poly pipe from rolls; 3 Point Subsoiler-Subsoiler Attachment | Agri Supply #73410 3 Point Pipelayer-Pipe Layer Attachment | Agri Supply #73622 Sent from my iPad using TractorByNet

I think that if you used above to lay pipe, the depth would easily protect your black poly pipe from the varmints.

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