Expansion tank addition

I have seen that recommendation, but have never understood why. They say it makes an accumulator tank unnecessary, but I don't know why they warn not to use one.

It won't replace an accumulator tank for me until it lets us flush the toilet all night without the pump coming on, like our 2 gallon tank does.

I've been a residential pump/watersystems installer/dealer for many years and have a question I just can't fathom on the accumulator system. My MH pump is one of the variable speed ones that warns against using an accumulator. Why?

rjxj wrote:

Bobbo wrote:
Actually, it makes NO difference where you put it in the water line, as long as it is in the cold water line. Mine is under the kitchen sink, about as far as it can be from the pump and the water heater. The cold water doesn't care whether it flows left to right from the pump, or right to left from the accumulator tank.

Note that I have a bypass valve so I can keep the pink stuff out of the tank, and a shut-off valve so I can flush the water out and pink stuff in to that line.

Could you possibly have a problem if it freezes and there is residual water between the valve and what's still in the tank stem? I mounted mine with the fitting at the bottom so even if I use air pressure or pink it will be fully protected. Maybe you have already been through freeze cycles so just asking.

It has gone through 10 degree weather with no ill effects. Any residual water that freezes will expand into the bladder of the tank, which will hold 2 gallons, so there is plenty of expansion room. You do realize that the tank is empty before I cut off the bypass? The only water is the ounce that is between the cut-off valve and the nozzle of the tank.

While the fitting at the bottom is ideal, it is not required. It has worked just fine like it is for 6 years.

And no, you don't need the fitting at the bottom to get out all the water. If the air bladder is pressurized higher than the pump cut-on pressure, it will completely empty the tank before the pump cuts on.

Pressure tank design

Tanks

Any precharged tank will pretty much empty no matter how it's mounted because of the air pressure on the bladder. As the air pressure in the tank compresses or collapses or crumples up the bladder it moves toward the fitting end, pushing the water out. However it should be mounted with the fitting at the bottom for more complete evacuation when blowing out or adding pink. It's not gravity that is forcing the water out, it's the air pressure in the tank.

Go down to the video " Flotech tanks what is a precharged tank"


Concept

The plumbing should be at the bottom of the tank so it can be drained completely. Having the tank half full from the beginning will have only half the effect, causing twice as many pump starts.

Bobbo wrote:
Actually, it makes NO difference where you put it in the water line, as long as it is in the cold water line. Mine is under the kitchen sink, about as far as it can be from the pump and the water heater. The cold water doesn't care whether it flows left to right from the pump, or right to left from the accumulator tank.

Note that I have a bypass valve so I can keep the pink stuff out of the tank, and a shut-off valve so I can flush the water out and pink stuff in to that line.

Could you possibly have a problem if it freezes and there is residual water between the valve and what's still in the tank stem? I mounted mine with the fitting at the bottom so even if I use air pressure or pink it will be fully protected. Maybe you have already been through freeze cycles so just asking.

Actually, it makes NO difference where you put it in the water line, as long as it is in the cold water line. Mine is under the kitchen sink, about as far as it can be from the pump and the water heater. The cold water doesn't care whether it flows left to right from the pump, or right to left from the accumulator tank.

Note that I have a bypass valve so I can keep the pink stuff out of the tank, and a shut-off valve so I can flush the water out and pink stuff in to that line.

Yes it can and does reduce electrical power consumption - How much?
That depends

Start up current on the typical water pump is HUGE but lasts for only a few thousands of a second. So it all depends on how many on/off cycles you are saving. Power consumption is only one of the several benefits. Noise reduction and pump longevity (heat reduction from constant on/off cycling) are are few more of the many benefits.

When a motor starts it draw a large amount of power to get up to running speed. So by putting in an accumulator tank you are cutting down the number of times the pump starts, there for saving a small amount of power. How much, I don't know. I wouldn't think very much.
But like others have said that tank is a very nice addition.

Dusty