Water Pressure Question

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Cclittle

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Hi everyone, I'm in IT so I'm having problems getting my head around water pressure.

My pump is 1/2 HP 10 GPM Franklin at 80 feet (water is at 50). So if I look at what Franklin pumps can deliver (curve/table), it shows me that such a pump can only provide 7 gpm at 60 psi and it can only deliver 10 gpm at 40 psi.

So if my use is under 7 gpm, i should have 60 PSI once the pump kicks in - is that right? (or less, because it also has to refill the tank?) Minus the restrictions/friction along the way.
If I use 10 gpm, I can only expect 40 psi?

Does it follow that if I move to a 1 hp pump, my pressure really should never drop below 60 psi as long as I'm using less than the capacity of the pump? (once it kicks in)

I've been told that 1/2 hp is too small for my house (and the calcs I've done really confirm that), but all a larger pump seems to do is provide higher pressure.

So if I want more pressure, I should just bump the HP of my pump... right?

Am I thinking on the right lines here?
 

Reach4

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You were doing fine until this:
Does it follow that if I move to a 1 hp pump, my pressure really should never drop below 60 psi as long as I'm using less than the capacity of the pump? (once it kicks in)
If you use a 40/60 switch, the pressure will vary between 40 and 60, even if you have a big pump. When the pump turns on, it has to supply your use, and it has to deliver water to the pressure tank. That takes time.

If you used a CSV, the pressure would climb faster, and it would stay near 50 more of the time with that same 40/60 pressure switch.

I've been told that 1/2 hp is too small for my house (and the calcs I've done really confirm that), but all a larger pump seems to do is provide higher pressure.
If you need more volume, a 3/4 HP 10 GPM pump would do it well. For 1/2 HP, a 7 gallon pump might be the better choice.

So if I want more pressure, I should just bump the HP of my pump... right?
If you want more pressure, adjust your pressure switch, and the air precharge higher. Or buy a 50/70 pressure switch.

Do you really notice the pressure change in use as your pressure varies between 40 and 60? What symptom do you really detect in use?

You should get one or more pressure gauges. If your pressure drops noticeably, you may have a restriction. Do you have a whole-house water filter?
 

Valveman

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A 1/2HP, 10 GPM at 50' should be plenty for a house. Now if you are irrigating the pump needs to be large enough to deliver the flow rate needed for the sprinklers, plus an extra 5 GPM for the house.

There are two ways you see low pressure in the house. One is that you are using more water than the pump can produce, and the pressure just stays low like 30-40 PSI while using water. The other is that your pump is delivering more than you are using, and the pump is continually cycling on and off between 40 and 60 PSI. Both of these things will make for low pressure in the house. Watch the pressure gauge during the times you experience low pressure and see which one of these things is happening.

If the pressure is low because the pump is cycling on/off, then a CSV holding a constant 50 PSI will make shower pressure much stronger than when cycling on/off between 40 and 60.

If the pressure just stays low when using water, you need a larger pump. A 1HP, 10 GPM won't deliver any more water than the 1/2HP, it would just work from a deeper well. A 1HP, 20 or 25 GPM pump will pump twice as much water as the 1/2HP from a 50' well. But then the pump will be cycling on and off, which will make the pressure seem low. Again a CSV holding a constant 50 PSI will make for much better pressure as well as eliminate the pump cycling and make everything last longer.

I would not turn the pressure switch up to 50/70, because from 50' depth that 1/2HP pump will just barely be able to reach 70 PSI.
 

Cclittle

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I do have a CSV waiting to be installed, and some other new piping (and 50/70 switch) to install with it that will remove several restrictions (higher diameter main line and fewer hard turns). The intent is to set things to 50/70 with the CSV at 60. Or maybe 45/65 with 55 (I'm leary about too much pressure straining the system).

How do I tell what the pressure is in the shower at the opposite end of the house (and up two floors)? If I remove the shower head, will a garden hose pressure gauge work on those threads?

No whole house filter, just a softener (at full main line diameter).
 

Reach4

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How do I tell what the pressure is in the shower at the opposite end of the house (and up two floors)? If I remove the shower head, will a garden hose pressure gauge work on those threads?
Showerheads use 1/2 inch NPT threads. You could make an adapter. However without flow, the pressure drop should be zero. If your adapter has a tee letting the showerhead release water, you still might be seeing the effect of restrictions in the diverter or other plumbing to the showerhead.

It could also be possible to make an adapter to a lavatory diverter thread. That may harder, because you have to find out what the thread is. http://www.acehardware.com/product/index.jsp?productId=28881166 is an adapter to some common threads. Waterbed fill kits often have an adapter.

You can attach a pressure gauge to the water heater drain. With that connections, you could compare the pressure during hot and cold test flows.
 

Cclittle

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"A 1HP, 10 GPM won't deliver any more water than the 1/2HP, it would just work from a deeper well."
Or... produce a higher pressure to top off a system set to 50/70, right?

You're correct in that for the house we don't need any more water, just more pressure. OTOH, we do have an irrigation system that begs for 15-20 gpm (5-6 heads/zone at 3 gpm), which we cannot adequately supply. I do know the pressure when they are running sits at 24 psi.

I still want to see the pressure in the shower on the second floor, as I'm sure it's different than the gauge in the basement. But how can I check that?

The litmus test is "what is the pressure in the shower when the dishwasher and laundry are running". Right now it's not good.

So maybe I hold off on the 50/70 switch setting until we get a new pump. Minimum it will be 3/4 hp 15 gpm - I'm just trying to figure if we should go up to 1 hp or not...

It seems like a 1 hp would be able to keep up the pressure for a small use in the house as well as supply the irrigation - better than the 3/4 hp. Right?
 

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With the CSV you can install as large a pump as you want, and the CSV will make it work like a small pump when small water is all that is needed. Probably not much difference in price from a 3/4HP, 15 to a 1HP, 20 GPM pump. The CSV will trim it down for you. Just make sure to start out with a pump that is large enough for the demands.

Just watch the pressure gauge at the tank and switch. If it is holding low, then you have even lower upstairs. If it is cycling on and off you will also have lower pressure upstairs. When you get enough pump to allow the CSV to hold a constant 55 or 60 PSI no matter how many outlets you have open, then you will also have a constant 50-55 upstairs.

What model/brand is the 1/2HP that you have?
 

Reach4

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My pump is 1/2 HP 10 GPM Franklin at 80 feet (water is at 50). So if I look at what Franklin pumps can deliver (curve/table), it shows me that such a pump can only provide 7 gpm at 60 psi and it can only deliver 10 gpm at 40 psi.
Not me. What Franklin pump are you looking at? Besides, you should be looking at 50 ft, so use the 60 ft column.

I still want to see the pressure in the shower on the second floor, as I'm sure it's different than the gauge in the basement. But how can I check that?

The litmus test is "what is the pressure in the shower when the dishwasher and laundry are running". Right now it's not good.
The lavatory faucet is probably a good indication of what is being delivered to the shower valving.

The litmus test of your pump and well system is what the pressure gauge at the pressure tank sees while you are drawing water. The drop from the pressure tank to your external loads is a test of your inside plumbing.

So maybe I hold off on the 50/70 switch setting until we get a new pump.
You could crank your switch up to 45/55. Watch the minimum run time. If the pump sometimes runs less than 2 minutes, I think you would be safe to crank further. 3 turns CW on the nut on the big spring is typically 10 PSI.
You're correct in that for the house we don't need any more water, just more pressure. OTOH, we do have an irrigation system that begs for 15-20 gpm (5-6 heads/zone at 3 gpm), which we cannot adequately supply.
I presume those run during the night when you are not taking showers. I would think you would be better off using 1.5 GPM heads and increasing the time. If you are running 40/60 and the pressure levels off anywhere near 50 while irrigating, you are tuned just right.

If you do go to a 1 HP pump, you would want it to be more than the 10 GPM pump, and you would want to go to an 80+ gallon pressure tank if you don't get a CSV. The CSV would let you not tune your irrigation.
 

Cclittle

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Sorry, so I do have 1/2 hp Franklin motor, but the pump is actually a 12 gpm Aermotor. I imagine it's probably delivering more like a 10 gpm pump after all this time. Many of my neighbors have the same (original install in our sub from 2003/4), but some have 3/4 or 1 hp pumps at 20 gpm (must have been upgrades).

I'm considering an upgrade to a Franklin series v 15 gpm 1 hp pump. Then there will be plenty of pressure from the pump, and a bit higher than 15 flow (from the 60 column).

In terms of my shower pressure question: I did build a gauge contraption for the shower head. It reads 38 psi at no flow (capped off) when the basement gauge reads 50 (40/60 switch). When passing water it drops to 22, and when we run another faucet 18, and with the tub running it bottoms out at 10 psi.

I can't find a local plumber to return my calls, let alone agree to do the rework I'm asking (change the 1" copper around my tank to 1.25" and the .75" PEX main line to 1" (there is no manifold) - nevermind install a CSV. They all want to sell me the stuff at their markups (I already bought everything needed), and only one of them knew what a CSV was (they seemed scared of it). So I've just started doing the work myself.
 

Reach4

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In terms of my shower pressure question: I did build a gauge contraption for the shower head. It reads 38 psi at no flow (capped off) when the basement gauge reads 50
A 12 PSI difference at no flow would be explained by a 27.7 ft difference in altitude. Part of the 12 PSI difference could be a difference in gauges.
 

Cclittle

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I get it. Many didn't seem to understand that removing restrictions improves flow and pressure.
 

Craigpump

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Sorry, so I do have 1/2 hp Franklin motor, but the pump is actually a 12 gpm Aermotor. I imagine it's probably delivering more like a 10 gpm pump after all this time. Many of my neighbors have the same (original install in our sub from 2003/4), but some have 3/4 or 1 hp pumps at 20 gpm (must have been upgrades).

I'm considering an upgrade to a Franklin series v 15 gpm 1 hp pump. Then there will be plenty of pressure from the pump, and a bit higher than 15 flow (from the 60 column).

In terms of my shower pressure question: I did build a gauge contraption for the shower head. It reads 38 psi at no flow (capped off) when the basement gauge reads 50 (40/60 switch). When passing water it drops to 22, and when we run another faucet 18, and with the tub running it bottoms out at 10 psi.

I can't find a local plumber to return my calls, let alone agree to do the rework I'm asking (change the 1" copper around my tank to 1.25" and the .75" PEX main line to 1" (there is no manifold) - nevermind install a CSV. They all want to sell me the stuff at their markups (I already bought everything needed), and only one of them knew what a CSV was (they seemed scared of it). So I've just started doing the work myself.


NOBODY is going to install what you have bought.
1) no markup.
2) if they install it, you'll want them to warranty it if it fails.
3) they have better things to do.
4) no one wants to work for someone they think knows more than they do.
5) you don't carry a steak into a restaurant and ask them to cook it, do you?
 

Valveman

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Craigpump, being an intelligent pump installer with common sense, you are in the minority. Having met with and talked to thousands of pump installers over the years, I can assure you that in the majority of cases the home owner knows more about pumps than the guy doing the install. Most installers are just glorified parts changers, that don't have a clue what they are doing. Everyday I hear from homeowners who say after doing a little research, they can tell their pump installer doesn't know what he is talking about. And they are right! At the very least homeowners should do a little research to be better able to understand what the installer is doing or not doing correctly.

I am very curious how this "Amazon Home Services" will work. And there are some really nice restaurants on the coast that will gladly cook the fish you catch. With everyone buying on Amazon, Ebay, etc., installers need to figure out how to charge for what they do or know instead of relying on the markup. Times are changing. And like it or not we are going to have to change with the times or go the way of the Dodo bird.
 

Cclittle

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Thanks valveman. Totally agree - the times are changing, and hats off to the people that realize that and change with it.
The fact is, I did find a good plumber willing to do it, but I didn't want to wait out his month of backlog. So I've resigned to doing it myself.
I've already replaced the PEX main line in my basement, and the wife has liked the minor pressure increase. Now I'm just sweating the copper a few connections at a time. Plus its fun to do new things and learn something along the way. Then it's on to a new pump (I'll let others install that) and back to planning my next reef tank with a basement sump setup (I get to play with PVC for that).
 

Craigpump

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I think there is a very possibility that Amazon will drive prices into the ground while profiting off the skills, knowledge and expertise of those who they sub contract to. As the the payments to the contractor are reduced, the end result will be unhappy homeowners stuck with poorly installed equipment installed by contractors who don't care.
 

Ballvalve

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I can't find a local plumber to return my calls, let alone agree to do the rework I'm asking (change the 1" copper around my tank to 1.25" and the .75" PEX main line to 1" (there is no manifold) - nevermind install a CSV. They all want to sell me the stuff at their markups (I already bought everything needed), and only one of them knew what a CSV was (they seemed scared of it). So I've just started doing the work myself.[/QUOTE]

Seems like a lot of trouble to change these pipe sizes unless they are so long as to cause restriction. 1" copper is enough. You are not running a car wash or motel. I have sprinklers here like a golf course, and most all lines are 1", but in the pump house I like to plumb with 3/4 or 1" clear braided vinyl hose. Find the USA /potable one. Dont break when frozen, "elbows" can be 8" radius, and you can repair things with a sharp knife and a screwdriver. Need more pressure, do it at the pressure switch.
 

Cclittle

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Amazon, if they get past where Sears did, will certainly affect prices. Personally, I don't think Jeff Bezos needs another billion $$.
If you want to hear how big stores mess with things, you should read "The Walmart Effect".

Thanks for your input everyone.
 
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