Water conditioning and other questions


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Old 01-03-04, 07:45 PM
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Water conditioning and other questions

My home water supply consists of the following:

From a 750foot-deep well pump (1-1/2hp, I think), the water goes to a 30gal pressure tank. At the input to the pressure tank is a well pump pressure shut-off switch and a chlorine injection pump. The system is set to cycle at 35psi. The water is then treated through a de-ionizer and a charcoal filter, and then goes to a 100gal storage tank which supplies the home including the out-door faucets.

I would like to eliminate the pressure tank and cycle the well pump with a level or float switch in the storage tank. Then use an on-demand pump to pressurize the pipes when a tap is opened. I assume a back-flow valve is needed. I’d like to get about 60-70psi. Where, in the system, is the pressure pump placed, and how is it made to turn on and off when a tap is opened or closed.

I’d also like to replace the chlorination with an ultra violet (UVC) sterilizer. Where, in the system, is it placed, and how is it made to turn on and off when a tap is opened or closed.

The house is a 65foot long, single story, ranch type. The piping is in the basement and easily accessible. An electrical sub-panel is about 5feet away from the water system

Comments and “how to do it” would be appreciated.

Thanks - Steve



Thanks - Steve
 
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Old 01-03-04, 09:38 PM
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Steve:

I have not seen what you are describing done in a multi-outlet plumbing system and am not sure how you could make this work.

I do this for reverse osmosis water dispensers in stores that are fed from a bulk tank, but can't see how it would work satisfactorily in a residential plumbing application.
The demand pumps that are used for water dispensers pressurize a single line from the water source and then use a built in close differential pressure switch to turn the pump on and off.
In a multi outlet apllication I am unsure of how you would make up for varying flow rates and not have the pump hammering on and off.
This is what pneumatic tanks are for.

Maybe someone else knows more about this and can teach me something.

My question is why do you think this is better than pressurized?
 
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Old 01-03-04, 11:18 PM
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Thanks for response. Had two well pump failures in 6years since I moved in. The last was seal failure. I’m thinking if the pump does not have to work against the additional load of the pressure tank, it would last longer. I don't know cause of first pump failure.

Steve
 
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Old 01-04-04, 08:41 AM
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Steve:

I think a demand system would be more work than trying to solve your existing problem.

Questions:

1. On your 750' well, how deep is the submersible pump.
2. Is the pump connected to a poly line and is there a torque arrestor on the pump?
3. What is the distance between the well head, the 30 gal and 100 gal tanks and what are the line sizes?
4. Is the check valve at the pump working and have you a check valve anywhere else on the system?
5. Have you vertified the cut-in and out pressures with a known reliable guage and what are the pressures?
6. Are your two pressure tanks bladder type or ones that need air volume controls and if bladder what is the air pressure or does water come out of the pressure tap?
7. If you were to run large flow taps, like say the h&c on the nearest bathtub, what would the cycles on the pump in terms of on and off times be like?
8. What hp, make and model pumps do you have?
9. Where exacly in the system is the pressure switch located?

Nosey huh?

Your solution may lie in your answers to these questions.
 
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Old 01-04-04, 05:57 PM
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Thanks Greg (AKA Nosey)

Q & A

1. On your 750' well, how deep is the submersible pump.

I was told it was at about 730feet

2. Is the pump connected to a poly line and is there a torque arrestor on the pump?

Poly line – Yes, torque arrestor – I don’t know

3. What is the distance between the well head, the 30 gal and 100 gal tanks and what are the line sizes?

About 75feet- Outside black plastic semi-bendable piping, guessing ¾” ID. Inside gray PVC, I think ¾” ID, then entire house distribution is ½” copper.

4. Is the check valve at the pump working and have you a check valve anywhere else on the system?

I didn’t think about a check valve, but it makes sense there must be one. What would be a failure symptom?

5. Have you vertified the cut-in and out pressures with a known reliable guage and what are the pressures?

No. I actually have another new gauge, but I won’t be able to change it for about a week as I’m helping my son re-do his basement. Present gauge reads about 35psi, I never thought to look at cycling pressures. I’ll do that tonight.

6. Are your two pressure tanks bladder type or ones that need air volume controls and if bladder what is the air pressure or does water come out of the pressure tap?

I’m confused, I have presently only 1 (30gal) pressure tank. The 100gal tank is just storage. I believe it’s a bladder tank, as it has a tire valve on it. To my knowledge it has never been pumped up or bled off.

7. If you were to run large flow taps, like say the h&c on the nearest bathtub, what
would the cycles on the pump in terms of on and off times be like?

With one of the two bathroom tub taps opened fully, hot and cold mixed, after a 15-20second delay, the well pump turns on (also chlorine pump) and stays on until tap is shut and after maybe 5-10 seconds later it shuts down. I don’t notice water flow change even if one fills the tub. If I turn everything on, including flushing two toilets, no major flow changes occur.

8. What hp, make and model pumps do you have?

I know nothing about the old pump or the new pump but think the new one is 1.5HP and was told it was marginal for my well depth. I told the well guy to install it anyhow as l had to go on a business trip and couldn’t leave the family, yada-yada.

9. Where exactly in the system is the pressure switch located?

The well pipe enters the basement wall about 1 foot from the floor. After less then 4feet, it connects to the pressure gauge and switch, and also the 30gal pressure tank through a 4” nipple. The chlorine is also injected at that point.

Thanks for your interest - Steve
 
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Old 01-04-04, 07:23 PM
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I briefly viewed over all the information and GregH made some really good points.


To add to this, the issue with the check valve. If you put one in,,,with 70 pounds on one side (house) and the well side (pump) at 35 pounds, the check valve will never open for the incoming water to replenish the system.


The elimination of a precharged tank would make the pump work without a reserve capacity, causing the pump to direct draw everytime the pump ran.



Pump failure has a great deal to do with the amount of head pressure the pump is having to go through to pump such a long distance straight up.


I haven't dealt with a pump deeper than 70' feet in my area, and 3/4 HP was more than enough.

I would suggest, since the time is coming for it to happen, is to replace the pump with the largest pump you can put in, piped to very large precharged tanks (100) and set the pump with a 40/60 switch. I cannot see why 75 would be needed, and I know that 35 probably has been hard to deal with at times.

I would say that a larger pump would not work as hard, two precharged tanks instead of one holding and one precharged will provide more of a range of steady pressure, and raising your pressure switch cut-in and cut-off to provide more likable pressure.


One thing you must consider, you are subjecting the feed line from pump to house and all the water lines and connections to a higher water pressure when you do this. There is a possibility that this can cause leaks in old piping in your home. It is not guaranteed, but it is worth mentioning.
 
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Old 01-04-04, 08:30 PM
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Steve:

If you could answer the questions in greater detail your problem would likely be solved.

By what you've given us so far it looks like the problem of blowing pump seals could be due to too much restriction in the supply line.

The depth of the pump and the level of the water in the casing would determine the load on the pump.
If you had a very large head and the supply line from the pump was undersized the pressure at the pump could be high enough to shorten it's life.
That 3/4"ID pipe would be 1" poly from the pump and would be too small as a feed line from the well.
With too much restriction on the supply line you could be reading 35 psi in the house but it could conceivably be double that at the pump. Increasing the size of the pump will give you a higher flow rate but would compound the problem of too small a supply line.

The 100 gallon tank would have been likely installed to increase the chlorine contact time but you could pressurize it and make sure the small tank is correctly charged to minimize the cycling of the pump.

The pump could be quite deep but the water table may be near the surface. If you pour a cup of water into the casing and listen for the time it takes for the water to hit you may get some idea as to how far down it is.
 
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Old 01-04-04, 09:00 PM
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1Geniere

hello, as for replacing your chlorine with an ultra violet light, good idea. that means no chemical feed pump, no contact tank. is that why there is a 100 gallon tank ?? and carbon filter if you choose.the only thing would be that your water should meet minimum requirements for the light to work properly. being your well is THAT deep i would think it is fine. second would be bulb replacement annually.if there is only one house on this well then that would be fairly inexpensive and quick to install (i would put right before the hot water heater) just be sure to buy one with the flow rate you have in mind, say single family 13,15 g.p.m. you could or should also install a flow restrictor so you could not possibly draw more than that.

as for your sumbersible pump, if i were you i would have a PROPERLY sized pump no smaller and no bigger than you need . if sized right it should last you the same as one at 20 ' depth. .the same for the pressure tank(s).. if the depth to pump is 730 feet that well must have a slow recovery or you could just raise the pump up. if it is down that far because of a low water table
then you must not have polyethylene pipe at the pump or it would bust. more questions... what size water line from pump to the house and the water (static) level in the well.
 
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Old 01-05-04, 09:24 AM
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Water conditioning and other questions

It's not uncommon to use a submersible well pump to supply a storage tank, especially if the well has a low yield or recovery rate, and use a surface pump to supply the house. Usually though, the storage tank is much larger than 100 gallons. I'm not sure if a 100 gallon storage tank is worth all the effort and the second pump, etc.
I know chlorine injection pumps are a pain in the rear, but there are certain conditions with well water where chlorination is necessary. Have the water tested to see if it's necessary.
As tinsmith suggested, you'll need to size the UV light to your family's needs. I've seen contractors install 12 gpm UV systems and never use a 12 gpm flow restrictor. You'll need to filter the water down to 5 micron, too.
I would advise against installing a larger pump in the well unless you verify that the well will handle it. If your pump/well guy only had one pump to offer you for your well (the 1.5 hp) I'd find another contractor. That isn't to say that the 1.5 hp isn't correct, but there are many different flow rates rated at 1.5 hp. The correct pump sizing takes into account the water level in the well, the drawdown level, casing size, discharge pipe size, the required flow needed, etc.
Before you do anything, contact a reputable pump/well person in your area and have them look your system over, have your water tested and get recommendations for corrective measures.
Ron
 
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Old 01-05-04, 12:17 PM
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Steve:

Ron brings up a good point in that pump and well maintenance is part of the plumbing trade but is also considered a specialty.

This is why pump selection is important and could be part of your problem.
Softeners are a relatively new thing to me but plumbers around here are more than happy to make the sale and do the install but when it comes to proper set-up, customer questions or problems they are no where to be found.

Ditto that on the chlorine too.
You should try to find out why it was installed in the first place.
It is possible that the bacterial content of the raw water is high or it is being used for another problem like rust bacteria which chlorine will control.
A 30 and a 100 gal tank would kinda add up for bacteria control contact time but it's hard to guess.

BTW, do you ever test the chlorine level at the taps?
You can do so on a tap that does not go through a carbon filter, with an inexpensive pool chlorine tester.
They are a bit out of range for residual chlorine in drinking water but will give you some idea.
 
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Old 01-05-04, 05:44 PM
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Thanks for the replies!

There is a lot in your posts for me to digest. I'll need some time to re-read them and get back to you with some more questions.

Thanks again - Steve
 
 

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