Water supply / pressure problems - suggestions?

[ByronBob]

Rat

Could he put a shallow well pump in with the W/A pipe on the intake side and put a bladder tank with an 80 gallon retention tank on the supply side? I thought with shallow well pumps the intake water was dead. I didn't know if he could do something like this or not?

 

[_RaT_]

Personally, if I have a supply that is good and it's just a matter of increasing pipe size, that is what I would do and forget anything to do with a pump. Pumping water can be expensive especially if you use it to irrigate. Increasing the pipe to 2" may cost 3 or 4 times more then putting in 1" PVC but it's still pretty cheap.

I have yet to ever use a shallow well pump. Out here they are pretty much obselete. A standard irrigation boost pump will supply a tremendous supply of water and can actually draw water if no pressurized supply is available. They are typically limited to about 60 PSI. Where I live I have a well for my domestic needs and have what is called ditch water for my irrigation. It is untreated snow runoff where the pressure is captured and brought to us in large pipes. We tie into it for a given charge and supply. We buy it in miners inches. A miners inch is about 11 gpm. Our pressure is about 120 PSI. It is a great and effective way to irrigate, something we need to do here in California in the summer as after May, we just don't get any rain. Some folks get the water but no pressure and must pump. To do even a few acres is very costly and can add about $300 or more to your electric bill each month.

 

[EastTexFrank]

Dave, the easiest way I've found to think about it is that your 30 gpm pump will put out 30 gpm with zero pressure on the outlet side. As you add pipe to the outlet side this creates a pressure loss when you pass water through it. Think of this pressure loss in the pipe as a back pressure against the pump and you will see why the flow drops. If the outlet line is too small or too long the pressure losses within the pipe can be higher than the pump is capable of putting out and there will be no water coming out the end of the line.

A positive displacement pump is usually a high pressure pump and will generally keep pumping until it blows something up, either the discharge lines, shut-off valve or itself. That's why they are usually fitted with a pop-off valve to bleed the pressure down before it becomes a "bomb". Centrifical pumps, on the other hand, are lower presuure pumps that will put out their maximum working pressure and then quit producing. You can shut the valve on a discharge line and it will pressure up the line to it's max working pressure and continue to spin to keep it at that pressure. That continued spinning with no throughput builds up heat and leads to burn out.

I don't know if this will be of any help. /forums/images/graemlins/confused.gif

 

[fractal]

</font><font color="blue" class="small">( Look at it this way. Try blowing water through a garden hose and then try blowing it through a straw. )</font>

More importantly for him is the following.

Head down to your local home store. Find two identical looking 1/2 inch hoses, one 25 ft and the other 50 ft. Peer around and make sure noone is watching. Wrap your lips around the metal end of the 25 footer and blow. Do the same to the 50 footer. Maybe a 100 footer if you can find one.

Feel the difference?

That "back pressure" or "resistance" limits flow. Your flow is a combination of pressure and volume. Decrease flow and you decrease one or the other or both.

This is basic physics and applies to a huge number of fields. It applies to water pipes. It applies to electrical wiring, both for your mains power wiring and your cable tv.

You ARE going to have losses. That is unavoidable. You can either crank up the initial pressure/voltage/signal so the you have the desired pressure/voltage/signal at the desired flow/current or you can increase the size of the pipe/wire/cable to reduce the loss. Alternately you can boost the pressure/signal one or more places along the transmission path.

If it were me, I would run bigger pipe. You are way undersized. A single booster pump risks bursting the pipe close to the pump. It has got to cost a lot more to install multiple booster pumps than it would cost to upgrade the pipe. It DEFINATELY costs more to maintain multiple booster pumps than to ignore a bigger pipe.

 

[_RaT_]

A great example. Around my place, if I use 75' of 5/8" hose (I only have one) on my largest RainBird impacthead which uses about 12 GPM, my throw is drastically dimished. When I go to my 3/4", it gets back to the diameter it can achieve. If I tie two 3/4" hoses together there is a noticeable drop. If you ever have been to a park or golf course, typically you will see 1" hoses and often times well over 100'. I can guarantee you it is not because they enjoy dragging the extra weight around.

"Find two identical looking 1/2 inch hoses, one 25 ft and the other 50 ft. Peer around and make sure noone is watching. Wrap your lips around the metal end of the 25 footer and blow."

Do you know where that end has been? /forums/images/graemlins/grin.gif

 

[Caddyshack]

Hi guys... Forgive me bringing up an old post but wanted to give you an update. We had a plumber check out our supply issues and they recommended we use a booster pump to improve pressure. I did the research myself and purchased a lesser expensive solution to see if we got good results. If this hadn't of worked, I would resort to trenching a new supply line.

On Saturday, a friend of mine helped me to install one of these Davey Pumps in my basement. We used the HS18-30HT1 model which is rated at 22+ GPM. The pump is very quiet and provides ample pressure and volume for our home. We are very happy at this point that filling a bath tub takes only about 4 minutes.

It doesn't address my supply issues to have water available to me for use when the municipal supply is interrupted but I plan to address that later this year.

Thank you again for all your help and input.

Ron