Accumulator tanks

[BradKW]

Are all accumulator tanks basically the same thing, or are there good/better/best choices?

My Googling seemed to only turn up different flavors of this SHURFLO ACCUMULATOR TANK and I thought I'd ask before looking further...thanks!

 

[highdesertranger]

that's is what I run. I have had it since the early 90's so about 25 years old. I have to pump it up about once a year now, so it must have a small leak. but for 25 years I would recommend it. yes they all work on the same principle. if you see that add and look under bought together they have the strainer. run that too, I have mine right on the intake of the pump. the strainer comes apart easy and the screen is stainless steel, so you can clean and reuse. I bought the strainer, pump, and accumulator tank all at the same time in the early 90's so I highly recommend Sureflo. highdesertranger

 

[ahh_me2]

I have been looking into these for awhile also, and I found out a few things,

#1- They are easy to make (bladderless)
#2- Store bought are usually the bladder type

Many acreages around here use them, although they are of a larger size.

The ones for RV usage are quite a bit smaller, but they all do the same thing, that is
they allow a certain amount of water to be used without the pump coming on.

They typically increase the longevity of the pumps as they are not cycling as often.

I am planning on getting one although I was going to get this Shurflo model

 

[GotSmart]

how much do you want to spend?  For a better selection look up pressure tank.

http://www.ebay.com/bhp/stainless-pressure-tank

 

[BradKW]

Do the pressure tanks require a compressor or some additional piece?

This is the pump I have: SHURflo 2088-474-144 Standard Demand Pump 24VDC

I want something that will provide a decent shower flow, but not interested in a compressed air system...

 

[ahh_me2]

The tanks are pre-pressurized, as HDR said, they do need topping up occasionaly, as they can/will leak a small amount of air.
They are usually set aroun 30-35 psi.
You can pressurize them with a bicycle pump

 

[Trebor English]

When the water heater heats up the water the water expands. There needs to be a place for the expansion to go. The accumulator serves as an expansion space.

 

[highdesertranger]

the expansion tank goes in right after the water pump on the main feed.  it has nothing to do with the water heater.  here is a simple diagram,



highdesertranger

 

[rvpopeye]

When filling a sealed off water heater tank the air will compress at the top and provide the expansion space.
It will eventually dissipate into the water and then you have a "waterlogged" tank which is detected by water dribbling out of the pressure relief valve , just drain it and refill as above to replace the air pocket.

 

[ccbreder]

A water heater tank does not need an expansion space. Cold in at the bottom, and hot out at the top. No air left. The said tank here is for the whole system and should be required for a system with a water pump.

 

[masterplumber]

A water heater tank does not need an expansion space. Cold in at the bottom, and hot out at the top. No air left. The said tank here is for the whole system and should be required for a system with a water pump.

Agreed with one caveat, if the water heater is in a sealed system it will need a small expansion tank or the T&P (safety valve) will constantly be dripping. The reason for this is water expands when heated. In a house without a check valve on the main, the excess pressure just backs up into the city main. If you add a check valve, which some water departments are doing to keep to protect the city water supply from any contaminants in the house system backing up into the city system, you need to add an expansion tank. So in a mobile application, if your supply tank is vented and you don't have a check valve anyplace between the tank and the water heater, you don't need an expansion tank, but an accumulator tank will help keep the pump from short cycling as others have said. If you have one of those older systems with a sealed tank that you pump up with air to pressurize, you most definitely need an expansion tank. 

Here's a short video that shows exactly what happens if you plug the T&P and don't have an expansion tank. And it's not just experimental, physics - people have died from these explosions. 

 

[ccbreder]

We started to use meter setters with check valves to protect our water system. They have to be double check. After 5 or so years, that program was discontinued due to maintenance costs on the check valves.