Water pressure/volume via well

[Richard]

In my journey to size/obtain a water softener, I have been told I need to find out my hardness (12 grains) AND I need to know the flow of my water.

Hmm..how to test?

Here's what I did and I'm looking for any obvious (or not so obvious /forums/images/graemlins/crazy.gif) flaws in my thinking or math.

I have a whole house filter after my pressure tank. I ran water until my pump ran & turned off (should be at high pressure now)

I shut the ball valves on either side of my filter and removed it.

I placed what turned out to be too small of a bucket underneith it and turned the water on. /forums/images/graemlins/blush.gif Please, no one ask me about the water GUSHING into the said bucket and ricocheting back out of said bucket all over me and the floor.

Cleaned mess up and started all over again getting a larger (6 or 7 gal??) bucket. Put bucket under the still vacant water filter and turned handle on for 6 seconds. Water GUSHED into pail.

I then turned water off and took a four cup (32 oz) measuring cup and started to bail the bucket out (of course after taking it outside, although with all the water already all over the place no one could have seen any different /forums/images/graemlins/tongue.gif)

I measured approximately 13.5 measuring cups (quarts) out, or (for a minute, multiplied by 10) 135 quarts. Divide 135 by 4/qts to gallon I got 33.75 GALLONS per minute /forums/images/graemlins/confused.gif
/forums/images/graemlins/confused.gif

I thought I had a 10gpm pump at the well and it's been explained to me that they will size it to TRY to get 10gpm at the HOUSE (and not well). So, to do that, they might put a higher powered pump in at the well and by time you get to house, you MIGHT have 8 gpm or you might have 13 gpm if they did their calculations near 'nuff.

33 gallons???????? Seems a bit off relative to 10 gpm

(I DO have over a 100 gpm well so it's possible they DID put a larger pump in to take advantage of that but they never told me they did)

So, does 33 gpm after the pressure tank make sense? The gauge was reading around 42/45 psi as best I could tell in light with the angle I had. I have 3/4 copper exiting the tank and again, this was taken through the oriface of the filter (no idea if it's 3/4 or not).

thoughts??

/forums/images/graemlins/confused.gif

 

[GaryQWA]

Your pump probably didn't run during the time you collected the water. The water came from the pressure tank which provides the pressure and volume of water while the pump is off. Use of the filter is what we would call an open discharge; an unrestricted flow and will provide more volume than if you had used a faucet.

The pump curve chart for your pump would show you that although the pump is rated at 10 gpm at whatever hp, it will provide much more water than 10 gpm unless the discharge is at the high end of its curve. As an example, your pump is set at 350' and has a 1 hp motor. At that depth, minus the static water level of 30', it may be capable of 30 gpm at a height (read head) of maybe 100' and at 60 psi. But if the static water level falls to say 100', it may only be able to deliver 13 gpm to 100' at 60 psi.

Try this for a more detailed explanation.
Pump tutorial

Gary Slusser

 

[Richard]

Let me rephrase that to see if I got the gist of it.

Pump is rated to deliver 10 gallons to a height of 100' (what ever that height contains to get out of well, up hill/other)

If the pump is 100' down then the math ought to work out near to 10 gpm.

now, if the pump is only at 50' depth, then it can deliver higher volume at the same outlet because it's pushing effort is less, therefore it can push more water/faster.

If the pump was placed 125' down, then it might only deliver 8 gpm because of the additional weight/height that it has to push to get water to same outlet.


close enough?

And your presumption that the well was off during my 'shower' is correct. As best as I know, it never came on.

Thanks for the info and I guess I need to get the wifey to select her faucets so I know the flow rate for the rainforest (shower).

 

[_RaT_]

It would not matter if the pump was 1000' down IF the depth of the water in the well is at or near the top of the well. That head pressure of water is what is also important. Typically a pump is designed for the water depth in the well as well as GPM needed. Make sure you are checking the pump GPM and not the combined from the pressure tank and pump. We have a pump at 100', we get 20 GPM from a 3/4 HP pump. pump.

 

[turnkey4099]

</font><font color="blue" class="small">( In my journey to size/obtain a water softener, I have been told I need to find out my hardness (12 grains) AND I need to know the flow of my water.

Hmm..how to test?

Here's what I did and I'm looking for any obvious (or not so obvious /forums/images/graemlins/crazy.gif) flaws in my thinking or math.

I have a whole house filter after my pressure tank. I ran water until my pump ran & turned off (should be at high pressure now)

I shut the ball valves on either side of my filter and removed it.

I placed what turned out to be too small of a bucket underneith it and turned the water on. /forums/images/graemlins/blush.gif Please, no one ask me about the water GUSHING into the said bucket and ricocheting back out of said bucket all over me and the floor.

Cleaned mess up and started all over again getting a larger (6 or 7 gal??) bucket. Put bucket under the still vacant water filter and turned handle on for 6 seconds. Water GUSHED into pail.

I then turned water off and took a four cup (32 oz) measuring cup and started to bail the bucket out (of course after taking it outside, although with all the water already all over the place no one could have seen any different /forums/images/graemlins/tongue.gif)

I measured approximately 13.5 measuring cups (quarts) out, or (for a minute, multiplied by 10) 135 quarts. Divide 135 by 4/qts to gallon I got 33.75 GALLONS per minute /forums/images/graemlins/confused.gif
/forums/images/graemlins/confused.gif

I thought I had a 10gpm pump at the well and it's been explained to me that they will size it to TRY to get 10gpm at the HOUSE (and not well). So, to do that, they might put a higher powered pump in at the well and by time you get to house, you MIGHT have 8 gpm or you might have 13 gpm if they did their calculations near 'nuff.

33 gallons???????? Seems a bit off relative to 10 gpm

(I DO have over a 100 gpm well so it's possible they DID put a larger pump in to take advantage of that but they never told me they did)

So, does 33 gpm after the pressure tank make sense? The gauge was reading around 42/45 psi as best I could tell in light with the angle I had. I have 3/4 copper exiting the tank and again, this was taken through the oriface of the filter (no idea if it's 3/4 or not).

thoughts??

/forums/images/graemlins/confused.gif )</font>

The problem is that you didn't measure the pump output, you measured the tank output in a free flow situation. To get what you were after you need to measure the flow prior to the tank with the pump running. You could measure it after the tank with the pump running but there could be some small difference between the two locations.

If you still have the original documents for the pump, what you need should be listed.

Harry K

 

[Richard]

(not arguing, I'm just ignorant of this stuff)

Shouldn't the pump be able to fill the tank faster than the tank can discharge? /forums/images/graemlins/confused.gif

In other words, if the above is true, I'd have even MORE flow with the pump running?

Seems to me it'd have to be that way or else you could easily starve the system.

no?

Would you find it better/more accurate if I were to connect a hose to the bib just prior to tank entry?

Bad thing with that, it uses a gate valve and as opposed to the ball valve, I don't think the gate valve could as quickly flipped on/off to get an accurate measure of flow unless perhaps I let it go for a longer sample period.

 

[_RaT_]

The pump would have a tough time being able to not only replenish the pressure tank, but be able to supply a fully opened 3/4" or larger pipe. If it is replenishing the pressure tank as well as supplying all the water an open 3/4" or larger line can supply, you have a well oversized pump. Remember, the tank simply holds "pressure", not water even though there is water in it. Much of that tank is air. You can see where the bladder is attached by looking at the indentation about 1/3 of the way up the tank. Above that is air when in the at rest state. The whole concept is sometimes difficult to grasp, but when a well is drilled, you typically get a pump designed for not only the wells capacity which is foremost, but also what your going to do. For dometic needs, 10 GPM can be enough. For irrigation, the sky's the limit. Homes that have less then 2 GPM from their wells around here require a holding tank. I know of several folks here at TBN that get less then that and don't use holding tanks so that means a shower and a toilet or a kitchen sink etc will compete for that water, a situation I'd prefer to avoid. The head and size of the pump typically expressed in HP will ultimitely determine just how much water a well can produce at a given point expressed in GPM. How long it can do it is determined by how quickly the ground water enters the well drilling through the fractures. That rate can vary throughout the year.

 

[GaryQWA]

"Shouldn't the pump be able to fill the tank faster than the tank can discharge?"

For most water uses, yes it will, but for peak demand flows, it depends on how the pump was sized and where it is set in the well and then, where the static water level is.

"In other words, if the above is true, I'd have even MORE flow with the pump running?"

Remember, the pump comes on just before the tank is fully emptied, so at peak demand you probably won't. And at those times, the well is drawn down meaning the static water level is lower and the pump has to work harder which relates to it delivering less gpm.

"Seems to me it'd have to be that way or else you could easily starve the system. no?"

That would mean the pump is not sized or set correctly as per that tutorial I included previously.

"Would you find it better/more accurate if I were to connect a hose to the bib just prior to tank entry?"

A hose with a substantially lesser ID than your plumbing ID won't tell you what you need to know to correctly size a softener, but it can get you close and you can add to that gpm.

"Bad thing with that, it uses a gate valve and as opposed to the ball valve, I don't think the gate valve could as quickly flipped on/off to get an accurate measure of flow unless perhaps I let it go for a longer sample period."

Have someone run water until the pump kicks on and time and collect water from then out of the filter housing. Or, remove the hose end sprayer and bend the hose shut and use that as the 'valve' instead of the plumbing stop valve.

BTW, in a 6" well, you have 1.47 gal/ft of water above the pump inlet. The recovery rate of a rock bore well (usually) doesn't come into play until the pump gets the water level down to the pumping level IF the pump was set based on that, which it should have been sized and set at 10-20' off the bottom of the well to allow use of all the storage. Many 6" rock bore wells have a 2-5 gpm recovery rate and provide water to the average home for decades without problems, or the addition of a tank/cistern. But adding more water uses such as sprinkler systems can cause serious problems that the original design, well or pump isn't capable of serving.

Gary Slusser

 

[GaryQWA]

Try this for better understanding of gpm and hp of submersible pumps/

http://tinyurl.com/9hlsd

Gary Slusser

 

[Highbeam]

You need to take the pressure tank out of the equation and pull water from the line between the well and the pressure tank. This strictly measures the rate at which your well system makes water to be treated. The rate will start out a little higher and should taper down to a lower consistent level if the well/pump combination was sized as not to dry the well.


The pressure tank adds all sorts of jive to the measurements. Measuring flow as you did was not a correct reflection of well production rate.

A typical fixture uses about 2.5 gpm. A typical 5/8 utility water meter allows about 15 gpm into a home at 50-70 psi.