Domestic Water Pump Selection (Submersible Versus Onground)

With a hole 90' deep, even with the water level closer to the ground level, I would go for a submersible. They are available in single phase.

Length of 6-8 inch dia bore hole in ground will be 90 feet (30 meters), Water Tank is 24 feet (8 meters) above ground level.

First, that's a 114 ft. static head you're talking about but you've made no mention of the actual pipe size. This is a necessary factor in any pump calculation. Next, single phase what?

Size of water piping is quarter of an inch dia (3/4 inch) already installed in the building from floor level to water tank at roof top (below ground has to be selected with the pump).

As for "sinlgle phase" the terminology refers to electical supply connection and being an electrical engineer myself I do not need advice in this regard.

I can share with you what I use which may help you in your design.

My well is 110' deep. 4" diameter and lined. The well is 40' from my home. The well poly tube (1 1/2") is buried 36" below grade and penetrates my basement wall. I used a Linkseal Modular Seal (http://www.linkseal.com/htmlPages/base_ls.htm) to seal the foundation penetration.

My pump is located in the basement and is a Utilitech 1-HP 21 GPM Shallow Well Jet Pump (operates on 120V). I have a 20 gallon pre-charge tank and two filters, one a paper sediment filter and the second a carbon cartridge filter.

My home has two bathrooms, dishwasher and cloths washer. I have the pump adjusted to 65PSI. This combination is adequate for our household. I am able to run all water appliances at once.

All the risers are 1" CPVC. Branch distribution is mainly 3/4" CPVC with some 1/2" CPVC.

The highest water outlet in my home is 22' above grade. There is no significant difference in the flow between the highest and lowest water outlets.

I decided on this system through conversations with neighbors in my area and getting suggestions from them as to what they use.

My system has been in use for 6 years. Have never run out of water or had my well go dry.

I like having the pump indoors for maintenance and re-placement ease.

The wells in my area are artesian (will flow at grade level about 3 gallons per minute un-assisted) so I don't know if this pump would have enough suction if your well is not artesian.

I do have one old timer in my area that swears by the submersible pumps but most are above ground (basement/crawlspace).

Most importantly, I would talk to someone in close proximity to your location that you can ask about their system.

Good Luck!

A submersible pump would be preferable in your case since this dispenses with cooling equipment and shielding requirements, and a three phase system compatiable to your domestic supply using a simple electrical power transformer. The requirements for selecting your pump are relatively simple, however, you need to specify size of pipework from the pump to the tank, the head of water supply, the rate of supply required, whether you need intermittent feed (i.e. on demand feed) or constant feed from tank to supply point. Your tank size will also be important because the pump needs to be sized to a specific flow rate to provide a set volume of water over a set period of time, thus determining the operational running time of the submersible pump.

There are many companies that will supply you will suitable pumps, and indeed help you select the correct size of pump for your needs; alternatively you can get a design consultant that will survey, plan your layout and supply you with a full bill of materials including all necessary pipe fittings, pump type, electical equipment and installation instructions; which in the end would save you the frustration of working it out yourself and possibly getting it wrong, and they would provide you at small cost the full package that you require within the budget you have set aside for your project. A good link would be www.apexappliedexperience.co.uk

Good luck with your project, hope everything works out for you.

ARJ

A two stage pump has two pumps, driven by a single motor. Two stages will pump the water further but will not increase pressure.

Submersibles give slightly better performance because they push the water up, not pull it up, as an above ground pump would.

Above ground pumps are easier to work on.

KJK/USA gives good advice. Ask the locals.

Two stage pump means that the pump has two stages within (2 impellers in series)..... It increases the output pressure but not the volume flow (contrary to what you wrote).

For your info, if the well is 30' deep, the pump should really be a submersible since you cannot suck water from the surface at such a depth, when the level start to drop: practically 20' should be a max for ordinary surface pumps...

My well is 250' deep. My submersible well pump has been in use since 1983 and still works fine, (knock on wood). I can't give you any specifics on it, but I can say that in my experience the submersibles tend to be very reliable. The guy that built and owned my house before me had a 600 gallon tank sitting on the ground next to the well that fed the house. Once I got to taking a closer look at everything, I realized that the holding tank had no air bladder in it, therefore, every time the water was turned on in the house the well pump was kicking on, not good. After some research I ended up eliminating the original holding tank and installing a 52 gallon diaphragm pressure tank in the basement, everything is working great and hopefully I've extended the life of my submersible even further, since it isn't running as often.

The pump stages are designed to increase volume at low pressure. As the line pressure increases the load on the motor increases. Stage pumps are usually use to be able to use a smaller hp motor. To move a greater volume of fluid until the line pressure reaches some level then the stages start to drop out. In the ones I am familiar it's done with internal relief valves that just let the fluid recycle in that stage of the pump. In multistage pumps each stage is set for a different pressure. As the line pressure reach that pressure that stage drops out reducing the load on the motor.

Reciprocating, geared, etc are the mechanics of the pump and how it forces the water. Didn't think they would use a reciprocating pump for a well pump but anything possible. Reciprocating like a car engine piston goes down sucks in water. Goes up forces it out. Gear pump two round gear intermeshed. As they spin the the water is drawn in to fill the void. Carrying the water around until the teeth mesh again forcing the water out.

GA bigg

I too have installed a lot of domestic pumps and could not agree more with the advice given. If OP is worried about low yield he should consider a pumptec to shut the pump off and then restart automatically. If the well has lots of yield then it would not be required.

The pump will need to be submersible at the bottom of the well, 2 stage should give you sufficient discharge pressure to overcome the 38metre head - no surface pump can draw water up a 30metre well 10metres is very nearly a vacuum, you are asking a lot of any pump to draw (suck) that hard

Centrifugal pumps can only "lift" water a maximum of 30 feet- start to flash due to suction going sub-atmospheric after that.

That said- since this is residential, low load serving a storage tank above grade, you definitely want a multi-stage pump for smallest housing and highest pressure.

Your only other option is to use a jet pump to get it to grade and into some type of receiving tank then use a small base-mounted OR inline centrifugal to push it up to the storage tank.

Go with the submersible well pump as others have suggested prior to my posting as a ground-mounted centrifugal pump will not have the ability to suck the water if its level is deeper than roughly 30 feet.

There's a lot of very good submersible well pump manufacturers out there, but one of the best around with a strong tech support and warranty is the "Goulds Pump Company" headquartered out in western New York State. I forget the actual name of the town , but if you run a Google search you'll easily find the link you'll need. Another thing is that many well drillers throughout the country usually carry Goulds pumps and replacemnt parts. And don't forget about installing a properly sized "EXPANSION TANK" (with the proper switching control gear) on the discharge line of your well pump! If your house is like most homes in the USA, aim for a MINIMUM 5 GPM pump discharge.....but a larger discharge is much more desireable. Just don't make is so large as to cycle the pump off and on constantly as that'll wear out your pump. Aim for minimum pump run times of 1 minute or longer and 10 GPM discharge.

Signed CaptMoosie, LPE

Civil Engineer

Following the latest reply by CaptMoosie, it is evident that the submersible pump option really is the soluton (as per my original posting), the size and type of submersible pump quite rightly as per CaptMoosie's comments is important, since the reliability, performance and service life will be dictated by the pump selection and the conditions within the bottom of the well. Additionally, an again by what is being said, the selection of the tank size is important and the on-off cycling of the pump is crucial because of preventing damage or undue wear-and-tear on the pump.

Go with the suggestions within this forum, find a good highly rated supplier for your pump and whether you do the installation yourself or get someone to fit it for you, make the right choice and you'll never regret it.

Hope your project is successful and you have years of untroubled pumping!!

ARJ

a 3/4 hp jet pump running on 230 volts (if you have it) with a 1 1/4" suction and foot valve, should do fine. Use a 50 gallon pressure tank with a "tee package" (pressure guage there) (also set cut in pressure 2-3 lbs lower than dry pressure tank bladder, and a spring check valve on the output of the pump. Also use a clear double water filter package so you can see the quality of your water.

Install foot valve to the bottom, then pull it up 4 feet, then prove the well by running it and timing the gallons per min. it produces. If it draws down below the foot it will suck air and lose it's prime. (Lower the well point) If the water is dirty pull it up a bit. (takes some trial and error, but make sure it is piped so you can "prime the pump)

Thak you all for providing me valuable information and advise.

My compliments individualy to M/s Hendric, RDGRNR, KJK/USA, apexmaster, lynlynch, LAA Luke, kramart, ozzb, kevinm, engineerk9, energygod, CaptMoosie and Craig Muhonen.

As for you Mr. bigg; it is great to have met you - SALUTE!