OT - Home Water Pump

This a bit OT but I figure there is a wealth of knowledge here.

I recently connected a large water tank and what I believe is a constant pressure pump to my house.
According to Pump Name Plate it is approx. 50 litres/min.
If I open tap located close to pump (tap is larger that house taps and is new and was added at same time as pump & tank) the pump happily kicks in and delivers contstant flow. The house is approx 20 metres from the Pump & tank. When I use ANY single tap in the house the pump starts and stops frequently. With most taps I can live with this but the Shower is a problem. I have found that if I turn on the Shower, the Bath Tap and the wash basin tap then the pump continues to run.
I think that pumps delivers too much flow for the house, the way I see it I have 2 choices.
1: Get a smaller pump (Pump Flow better matches what house can actually use)
2: Fit a Pressure accumulator between House & Pump so that reduce flow from House "bleeds" pressure from accumulator and pumps starts/stops as it needs to maintain pressure in accumulator without me leaping out of the shower due to pressure/flow fluctuations.

Anyone out there have better/smarter solution ?

Hi Dua


Can you provide a little more information about your set-up?

what pump is it make/model? and do you have pump curve for it?

How do you control start and stop the pump? (controller make/model)

How do you control the level in the breaktank and does it interact with the pump controller?


Adding a accumulator is always a good idea(a must even) if the pump is fixed speed, this will help reduce the number of start/stops cycles, there will be a max number of start/stops pr hour for the pump

/fryman

Pressure and Flow are proportionate
For a constant pressure you need to limit flow below maximum.
place a bucket under the shower head / bath tap run the water until full.
most buckets are 4.5 ltrs. @ 50 ltrs per minute it should fill in less than 6 second approx.

with any pressure pump system an accumulator is always a good Idea.

are you using a low flow shower head.

I assume your are not on a city water supply

I tested shower flow with a twenty litre esky. Flow WAS approx. 9 litres/min before I removed flow restrictor. I have access to City water supply, but with lots of shedding water tanks seemed like a good idea.
I'm guessing (esky is back in son's boat) that with flow restrictor removed shower flow may be around 20 L/min.

I would prefer to NOT get a smaller pump as then I may experience problems when demand is high(shower & dishwasher etc.)

Is the pump very noisy when you try to run shower.
50 l/m reguires pipe sizing accordingly.
I have forgotten the equation - too early in the day.
- inside diameter of pipe
- PI
- area of a circle
basically ltrs/mn needs flow allowing ltrs per min.
if the oriffices are too small you will never reach the flow.
@ 9 ltrs per minute up to 20 ltrs per minute
it is probably the size of your pipes.
the biger the pipe the higher the flow

this has inuendoes - let's not go there.

I live in a rural area where I and all of my neighbors get their water from wells. I've never seen a home well water system that didn't have an accumulator.

Same with me. Every home out here has a private well and an accumulator holding the water. Then out of there it feeds the house. I cannot see any reason why you would not want an accumulator to keep pressurized water in your system without the pump having to run.

This solves the on/off you get when you are using water away from the system. It also allows you a storage of water in case the power goes out.

Been there done that, a few times:

Your pump start pressure is bouncing your pressure switch. It needs a shock absorber, which can be accomplished by locating the tank as close as possible to the pump, use big pipe, manifold to the tank, and carefully locate the pressure switch and check valve so that the surge hits the tank first.

The tank needs to be near the well head especially if you have too much pump for your discharge line diameter and length.

If it's a bladder type tank with a few years on it, and there is ANY silt in the well, the bladder can literally stick itself closed. This happened to me a year after I solved the low flow short cycling issue and nothing else had changed. Only buy tanks with a bolt on flange on the bottom ,so you can get out the air ratchet and cleaned the mud out of it and unstick it. Those with welded bungs are harder to fix, you need a big relief hole on the air side.

All this assumes you matched your bladder air pressure chart and pressure switch settings.

I replace a 1/3hp submersible with a 1hp 5 years ago it's 30 meters away from the house, and I have had the tank in three different locations. With the worn out 1/3hp pump, the tank was fine in the kitchen where the dishwasher used to sit.

With the big pump, i had to move it back to well head. It is about 20gal I think, small rebuildable bladder tank at the well head. I bought the $30 1" brass tank tee and put the pressure switch on a 6" copper pipe nipple sticking straight up at the farthest downstream port.

I then put a 33 gallon tank under the cabinet and had 40-60psi at 30gpm throughout the house until my lack of good filtration caused the big tank to "mud-weld" itself shut and become a lawn ornament. The pressure is still good, but the flow was much better with both tank.

That's when I learn never to buy a bladder tank without a removable flange on the bottom. You can't pull a 2 foot diameter leaking rubber balloon (1/4" thick) through a 1" NPTF fitting.

Here's my thread on a related subject:

http://www.plctalk.net/qanda/showthread.php?t=61911

I need to update that thread with some fresh pics, but I am holding out until I finish my Star Trek doors on the front porch with the Click Steve gave me...have everything I need to build the automatic sliding door except for two DC micro cables about 5 meters long and a 10' stick of 1" angle iron, and about a solid 6 hours free daytime. The solid 6 hours is the hardest part to acquire.

Paul, I gotta couple of those cables if you need em let me know. the 6 hours, I have no idea where to get those. LOL

No sir, you have been kind enough. I just need to get out my credit card and go to automationdirect.com...I don't have to go out in the cold 40mph wind gusting to 60 to accomplish that before I crash...get up at 3:30, work 5-1:30, go out to eat and watch football all day, come home and hang tile, repeat...I get three days off next weekend though, and surely, I will get the doors working, actuators or not.

Ian - It works fine (I can have a good long shower) if I open all 3 taps in the bathroom, so I assume that any pipework between the house and pump is sized OK. Problem seems to be that the flow I need to achieve requires me to have multiple taps open.

Steve & Tharon - Here (Oz) we are seeing more and more of these "constant" flow pumps. I But I do like the idea of an accumulator if only for the fact that it reduces the number of starts.

you may need to bypass the unused flow back to your tanks

Dua Anjing said:

Ian - It works fine (I can have a good long shower) if I open all 3 taps in the bathroom, so I assume that any pipework between the house and pump is sized OK. Problem seems to be that the flow I need to achieve requires me to have multiple taps open.

Steve & Tharon - Here (Oz) we are seeing more and more of these "constant" flow pumps. I But I do like the idea of an accumulator if only for the fact that it reduces the number of starts.

Click to expand...

The accumulator is a requirement. Your pump duty cycle will be exceeded without it, unless it's a jet pump with a return line.

Tell us more about the location and type of pump you are using?

Even before I replaced the worn out pump, it would occasionally short cycle like that, and making the pipe nipple for the pressure gauge longer seemed to help, but then more likely to freeze in the winter here too. I seriously thought about installing two timing relays to limit duty cycle minimums on mine in the winter the first time my tank was acting up, but I didn't have the materials for that and I live 20 miles from anywhere, so I just played plumber in the 20 degree cold all day instead.

Steve Bailey said:

I live in a rural area where I and all of my neighbors get their water from wells. I've never seen a home well water system that didn't have an accumulator.

Click to expand...

Nor would you want one. The pump would end up running whenever there was a call for flow. A good way to wear out a pump.

I grew up on a well system and when (not if) the bladder in the pressure tank ruptured, the pump would cycle every time there was a call for water.

Dad wasn't mechanically inclined, so it was left up to me to change out the pressure tank (and water heater) at the ripe age of fourteen.

I learned quite a bit from these repairs, the most important one being that pipe dope is essential for the fittings on gas lines.

That, and don't check for gas leaks with a lighter...

Tell about your next project. You're gonna burn that pump out by Wednesday without a bladder tank volume accumulator.