ok.

did i violate some plumbing forum protocol or what?

Perhaps your description is a bit vague

With the almost nil inlet pressure created by the static pressure in the tank, combined with the friction of the pipe between the tank and house, a booster pump would not work.

You will need a well pump such as a jet pump with tank & switch.

Not enough info there to offer much more advice

you are absolutey incorrect. i don't need a well pump.

i still like this site though, because of people like lazypup and the irish dude, they have character and know what the heck they are talking about, (unlike others who offer opinions dressed up as fact)

BTW the pump i need, no thanks to you, is an MQ 3 -45 made by grundfos.

ciao (that's italian, just in case it was too vague. :) )

Contrary to my esteemed colleague zl700, I don't find the description vague at all. On the other hand, I see a number of questions that were not mentioned.

Obviously the tank is open to atmosphere and is only used as a storage vessel. Why not seal the tank and allow the deep well pump to generate the required pressure to the structure? Allowing of course that the tank is certified as a pressure tank ,which I doubt because a 2500gal pressure tank is an extremely expensive piece of equipment.

The average family of four consumes 300 to 350gal/day. Why have a 2500gal tank? Is this house built in an arid region where the well may not consistently produce thereby requiring water to occasionally be brought in by tank truck?

The post says the source of supply to the structure is 5' below the outlet of the tank and they measured 2.5psi at the source. Water exerts 0.434psi per vertical foot static head pressure therefore the level of water above the point of entry was 5.76' above the point where the pressure was measured. If the point of entry is 5' below the tank as stated that means there was only 9" of water in the tank at the time of the measurement; assuming of course that both the 5' figure and the meter used to test the pressure are accurate.

Based upon the fact that they have a 2500gal above grade tank I am assuming that this structure is in the sun belt where freezing is not a issue. From this I conclude that the supply line from the tank to the structure is buried at the code minimum depth of 12" below average terrain and no doubt the "Main Water shutoff valve" where they made the pressure measurement is in a vault on the main line, also 12" below grade. If we then consider a house on slab, with the slab a mere 6" above grade, the floor of the structure would be 18" above the main water line. If we then allow 36" vertical height for the kitchen cabinet, and assuming the kitchen faucet spout is 4" higher than the counter top the kitchen sink spout is only 11" below the water level in the tank and the pressure at the kitchen sink is presently about 0.35psi assuming no friction loss in the piping. This also means that if they turn on the shower the water will rise about 1/2way up the shower riser and no water will reach the shower head.

The post says they have 1-1/2" CPVC from the tank to the main water shutoff valve. Sight unseen I would bet that is PVC, not CPVC. CPVC is made to the IPS (iron pipe standard) in both sched.40 and sched.80 but it is generally only available through a commercial plumbing supply by special order and although it is code certified for residential water supply, most local codes will not permit sched.40CPVC because it is exactly the same size as PVC and when making repairs homeowners tend to use PVC fittings. Cod prohibits gluing dissimilar types of pipe or fittings together. The CPVC commonly used in residential construction is CPVC-CTS. CTS indicates that it is made to the Copper Tube Standard.

1-1/2" is fantastic because with a demand of 17.5FU, even at maximum flow there would be almost no friction loss, however the 3/4" PEX from the shutoff into the structure will not pass code. 3/4" pipe is rated for a maximum of 9.5FU's. At 17.5FU's the code minimum is 1". This is extremely important in this application because a 3/4" line only has about 1/2 the cross sectional area of a 1" line. (The volume of a 3/4" line is actually 0.56% the volume of a 1" line.)

The actual volume of flow is determined by the size of the orifice in the faucet or valve where the flow is occurring, however, even though the volume of flow will remain the same, the velocity of flow in would be nearly twice as fast in a 3/4" line as it would in a 1" line and as the velocity of flow increases Friction head loss increases exponentially not to mention that pipe wall erosion occurs when the velocity of flow exceeds 10ft/sec in copper or 12ft/sec in plastic pipe.

AS zl700 has already mentioned, a "boost pump"' will not work in this application because there is not sufficient static head pressure to meet the "inlet pressure" requirements of a boost pump.

The only solution I see would be to install a "shallow well Pump" and pressure tank. Shallow well pumps can work with an inlet pressure that is minus 12psig.

Lazypup,

You are right the pipe is pvc not cpvc.

The tank is not a certified pressure tank.

Everything is underground at a minimum of 18" below grade.

I went to the property yesterday and while I was there my neighbor happened by and I mentioned my pump issue to him. The long and short of it is that he took me to his place and showed me the tank and pump system he uses, which, it turns out, is identical to the system I am installing. He uses a Grundfos MQ 3-45. With one expection, his supply into the house is one inch, where mine is only 3/4 inch. The only problem I now have is increasing my supply line into the house to 1 inch. Fortunately I have not buried the trench from tank to house yet!

I am confused about one thing, however, it is the way pump terminolgy gets tossed around. The manfacturer calls the MQ series pump a booster pump, but it seems to me that the characteristics make it a shallow well pump. By that I mean it has a lift capacity of 25 ft. Wouldn't that make it a shallow well pump? Maybe it is both. In any case i've seen it work at 0 psi inlet pressure, it seems to me that is should also work at at least -10 psi inlet pressure given that it can lift water up 25 ft of pipe?)

in any case, thanks!

Thanks

zl700, I like short concise and to the point. No need to write a book.

People who ask advice and then insult have been looking at wax rings too long.

Theotherone is awfully touchy being that you asked.

You see the majority of pressure boosting pumps require a minimum inlet pressure to be capable of boosting, thus my comment on inlet static pressure.

So you stumbled upon the Grundfos MQ, great! But you do know it is a simple shallow well pump? (which I suggested you would need) that can double as a pressure booster in many applications if applied carefully, such as max inlet psi is 45 or you will blow the seal and send water into the electronics compartment.
So don't feel so sure about yourself and be so all-knowing, after all you asked the simple question.

Your last post was a backpedaling because of Lazypups confirmation of my original statement?

theotherone

In regards to your question about pump terminology, I too was a bit curious so I pulled down the specifications manual on the Grundfos MQ series pumps.

Although they are officially designated by the manufacturer as "Boost Pumps", and primarily used in that application, it would appear that they are in fact a hybrid that has both the characteristics of a boost pump and a shallow well pump.

Generally "Boost pumps" are used for two distinct purposes;
In a residential application they are used when the municipal main static head pressure is less than the code-required minimum of 45psi.

A vertical inch column of water weighs 0.434lbs (Vertical Static Head) and consequently one PSI of pressure will lift a vertical inch column of water 2.304'.

In commercial applications when building a high-rise structure often the static head pressure from the municipal main is not sufficient to push water up to the upper floors so boost pumps are installed throughout the building to assist the lift.

Even though boost pumps are used where the existing static head pressure does not meet code-minimum none-the-less as was previously stated by zl700, boost pumps generally require a minimum of 10psi inlet pressure and in most cases they require the inlet supply line to be one nominal trade size larger than the code minimum for the demand of the structure.

On the other hand, the Grundfos boost pumps are designed to be used in applications where you cannot achieve 10psi minimum inlet pressure, such as when pumping from a tank such as yours and even though they are officially designated by the manufacturer to be boost pumps, it appears that the Grundfos MQ series are in fact technically a shallow well pump, which means that they will operate with a negative inlet pressure. In fact, the Grundfos manual states that in applications where the inlet pressure exceeds or is likely to exceed 10psi they require a PRV (pressure reducing valve) on the inlet line to limit the inlet pressure to 10psi or less.

thanks lazypup,

alphonse and zl ditto head can go pound sand.

is that clear and concise enogh for you to understand you sarcastic pricks?

seems you got it fixed, I thought I would answer couple questions I saw

Well pumps only have a discharge connection, if this pump your using has an intake connection and discharge connection and is placed inline between the tank and house then it's a booster pump.

All pumps have lift, which is called head pressure or feet of head, you can't have pressure without head. Even your tank has head pressure. At 5 foot evelevation your tank would have 5 x 2.31= 11.55
Your loss in psi is due to friction loss in the pipe. The smaller the pipe the more friction loss so its good your upping the size of the pipe where you can.
have a good day

Quote"Well pumps only have a discharge connection, if this pump your using has an intake connection and discharge connection and is placed inline between the tank and house then it's a booster pump."

WRONG-that statement is as full of beans as a good pot of Mexican chili. If a shallow well pump has no inlet line pray tell how does the water get up to the pump? Perhaps it jumps up?

Submersible Well pumps only have a discharge connection, that is.

zl700

i wholeheartedly agree that submersible well pumps only have a discharge line, but I think you would agree that not all well pumps are submersible.

lol
You seem to be very informed person lazy. I really don't wish to provide a 2 pager on a simple answer. This is why I did not mention an special notes saying that I was talking about an intake connection and not an intake access point/inlet. (well other than typing it)