Any harm in reducing intake pipe size?

[Banjo Bud]

I'm having a heck of a time trying to punch a hole under my driveway for my shallow well intake pipe, which is 1-1/4" PVC. I do have a conduit under the driveway now but there's not enough room in it for 1-1/4". However, there is room for 1" PVC. Will it hurt to reduce the intake pipe size to 1"?

 

[Reach4]

1 in. PVC Pipe is 1.315 in. OD. If you went to 3/4 inch PVC, could you get across the driveway without having to add a coupling?

How about putting 14 AWG wires and 3/4 inch PEX thru there to your new 1/2 HP 10 GPM submersible pump? The pump would be horizontal inside a flow inducer sleeve, which is a 4 inch PVC pipe to route cooling water past the motor. Priming drama gone.

 

[Sponsor]

 

[Banjo Bud]

I just had a brainstorm. I measured the ID of 3 different diameter pipes and also calculated the area.

1-1/4” = 1.340”ID = 1.410 sq in.
1” = 1.025”ID = .825 sq in
3/4” = .810”ID = .515 sq in

So, three 3/4” PVC pipes will flow a little more than one 1-1/4” PVC. I tried and I can get three 3/4” PVCs through the conduit that already has a pipe in it. So, what do you guys think of running 1-1/4” PVC from my spring to my driveway, then putting in the appropriate tee’s etc., to branch it into three 3/4” PVCs to go through the conduit under the driveway, then change back to 1-1/4” to go to the house? The driveway at that point is about 14’ wide and the pipe won’t fit if I use couplings. Maybe they sell it in 20’ sections. Or maybe I’ll buy a roll of 3/4” poly. The problem I have with poly is the fittings. If I need to rejoin up to PVC, the only way I know is those internal hose barbs for poly. The ID of those for 3/4” poly is .560”. So, even though the ID of 3/4” poly is .810, it’s useless because the fittings effectivly reduce the flow to that of a 1/2” PVC.

 

[Reach4]

Poly has the advantages of no seams if you can curve it. Yes, you use barbs with "SIDR" poly pipe. You put two worm gear hose clamps at each end of the tubing. You heat the pipe in hot water to make it more flexible to fit over the barb.

You could also use PEX. I don't know how heavy-wall a poly suction pipe has to be.

PVC is available in 20 ft lengths.

I can tell you think that submersible pump idea is not for you.

 

[Banjo Bud]

Well, the submersible is a good idea, but ONE, I already have the shallow well pump, and TWO, there's something I just like about having the pump accessible. But, if I can't get anywhere with this {1 into 3 into 1} pipe idea, I'm pretty much screwed with my shallow well. So, in that case, I will either go submersible or scrap the whole water well idea and continue to pay $160 a month for county water.

 

[VAWellDriller]

The 3 pipes into one idea seems like it could get really messy with fittings; I wouldn't do it. My first thought would be to just reduce it to 1" since that will fit. If it's a really long run to pump, then my 2nd thought would be to reduce it to 1" just under the driveway, have 1.25" run on either side of driveway. Another option would be to run 1.25" to the driveway, and switch to 1" for under and the end of the run.
Couple questions, 1) what are the distances.....overall from pump to intake? 2) Where is the driveway along the run? 3) what kind of flow are you hoping to pump (approximate)?

 

[Banjo Bud]

Ok, starting at the foot valve, It’s 20’ from foot valve to drive, and a rise of about 3’. Then 14’ wide drive, with a rise of about 1’. Then 40’ to pump with a rise of about 3’. 7-8 GPM would be good. The total rise is about 7’ from foot valve to pump, and total distance is about 75’. The pump is a Gould’s J5SH which should put out 10 GPM at those stats. And I agree, 1 into 3 into 1 is going to be a fitting headache. But I just tried another thing. I can fit one 1” plus one 3/4” in the conduit. That might not be so bad to tie those two into the
1-1/4” on either side of the driveway.
1 into 2 into 1. And it’s ALMOST the same area as a 1-1/4”. It’s only about a 5% loss.

 

[VAWellDriller]

I wrk with mostly submersibles but I know I have seen longer runs than yours with just 1" suction working. It might now be ideal but it works. You dont have much vertical head and you dont have a very high flow rate. Maybe some others will comment but I think it would work just fine for your distance and flow to run 1.25" to the driveway and switch to 1" for the rest of the run.

 

[Banjo Bud]

That would be nice. Do I hear a second on that?

 

[Banjo Bud]

Here’s my plan. I will try priming it before I fill in the ditch. If I can’t, I’ll cut and cap where the 3/4” enters the 1-1/4”. Then I’ll just use it that way. The thing is, 1” pipe doesn’t just carry a little less water than a 1-1/4”. It carries only about HALF of what a 1-1/4” carries. That’s a big difference.

 

[Reach4]

Here’s my plan.

1. Is that conduit being used to carry wires now?
2. I see the 3/4 and 1 inch in your sketch. Are those alternatives? No way you can put both 1 inch and 3/4 PVC through the conduit at the same time. I doubt that you can get 1 inch thru. Test the fit before going to the trouble of getting some 20 ft long 1 inch PVC.

 

[Banjo Bud]

I test fitted the pipes. There’s a

1-1/4” and 4 small wires in it now. It’s 4” bell end electrical conduit. It’s a lot smaller diameter than 4” PVC. Anyway, I had a 10’ piece of it laying around so I put a
1-1/4” PVC through it, then slid a 1” and a 3/4” through it. It’s not sloppy by any stretch, but it’s not tight either. I just have to make sure I avoid the wires. I’ll look through it and see where they are before I slide the pipes through.

 

[Reach4]

Got it. I somehow had the impression that your conduit was much smaller than it was.

1-1/4 PVC is 1.660 OD. So looks like you will be fine. Good deal.

 

[Banjo Bud]

Well it’s certainly smaller than I’d like. If I’d have used regular 4” PVC, I wouldn’t be having this trouble. I figure the 3/4” has to be under the 1” or it won’t fill during a prime. Thoughts? And I guess I lied. It’s 3” electrical pipe. Measures 3.050” ID. It was free. That’s why I used it. Free isn’t always worth it if you know what I mean.

 

[Banjo Bud]

Well, it won’t work. After digging down to the conduit, I found that the 1-1/4” that is through it already, is kind of in the center. And no way to move it because it tees 6” from the conduit and goes both ways. So now plan D. Rent a bore tool and bore a new hole under the drive. I’ve only been at this a week!!!

 

[Texas Wellman]

I’d go 1” all the way thru then upconvert back to 1.25”. I use 1” suction pipe all the time but not as long of a distance.

 

[Banjo Bud]

I can’t get ANY pipe through the conduit, let alone a 1”. The
1-1/4” PVC pipe that is in the conduit now, and has been for years, is positioned roughly in the center of that conduit, and can’t be repositioned to another spot. This leaves absolutely no room for another pipe to go into the conduit. So, I’m abandoning that conduit. Now, this means I need to find another way to get a pipe under the driveway. The only way to get under the driveway in another area is to bore a new hole and forget the conduit. The good news is that as long as I’m boring a hole, I’ll make it big enough for
1-1/4” PVC.

 

[Reach4]

can’t get ANY pipe through the conduit, let alone a 1”. The
1-1/4” PVC pipe that is in the conduit now, and has been for years, is positioned roughly in the center of that conduit, and can’t be repositioned to another spot. This leaves absolutely no room for another pipe to go into the conduit. So, I’m abandoning that conduit.

What is the existing 1-1/4” PVC pipe? Can you remove it, or downsize it?

 

[Banjo Bud]

Sprinkler system. Gotta stay.