How do I know if we really need an accumulator tank?

josrulz · #1 (**permalink**) 10-26-2010

Our fresh water system has a 1 QT accumulator tank, which appears to be original to our 1984 boat. The water pump is definitely not original, and you can tell from the mounting locations that it's a replacement.

I recall reading somewhere that certain types of water pumps need an accumulator tank, while others (perhaps more modern pumps?) do not. However, I don't recall the criteria there.

The reason I ask is that the accumulator's location makes the leftover space in the compartment somewhat unusable. If it were removed or relocated, I might be able to use the space for something else.

So anyway, how do I tell if the pump I have requires the accumulator, of if it's just a nice-to-have? The pump is a ShurFlo 2088-423-344. Just for the record, if I need the accumulator, then so be it. Just thought I should ask.

Thanks!
-J

jackdale · #2 (**permalink**) 10-26-2010

An accumulator is nice as it keeps the system pressurized. Otherwise, the pump comes on every time you turn on a tap / faucet.

josrulz · #3 (**permalink**) 10-26-2010

Quote:

Originally Posted by jackdale

An accumulator is nice as it keeps the system pressurized. Otherwise, the pump comes on every time you turn on a tap / faucet.

Mine kind of does that anyway, which makes me wonder how effective it is. But of course maybe it would be a lot worse without it.

I was reading up on pumps--is it the variable speed pumps that don't need the tank? I'm pretty sure mine's not variable.

sailingdog · #4 (**permalink**) 10-26-2010

Second what Jackdale said, though with some of the newer variable pressure pumps, which are quieter, it isn't as much of an issue.

Faster · #5 (**permalink**) 10-26-2010

You may have lost the air charge on the accumulator... there's usually a schrader fitting to pump up the bladder.. if that's leaked out you will have lost the pressure pad that makes the thing work..

We have a pretty good sized one and it's nice not to have the pump come on every time you open the tap. To fill a regular kettle our pump comes on about 3 times for a few seconds each time...

hellosailor · #6 (**permalink**) 10-26-2010

"there's usually a schrader fitting to pump up the bladder.. "
And after all these years, the bladder may have ruptured. If the accumulator tank is in the way, it might be worth replacing it with one that's installed someplace more convenient for your needs. As long as it is in between the pump and the tap, the exact location isn't critical. they're not very expensive. (Or at least, they weren't.)

josrulz · #7 (**permalink**) 10-26-2010

Quote:

Originally Posted by hellosailor

"there's usually a schrader fitting to pump up the bladder.. "
And after all these years, the bladder may have ruptured. If the accumulator tank is in the way, it might be worth replacing it with one that's installed someplace more convenient for your needs. As long as it is in between the pump and the tap, the exact location isn't critical. they're not very expensive. (Or at least, they weren't.)

You both may be right about the bladder and/or the air at least. I found a spec sheet online for the accumulator tank dated 1980. So it's an old model for sure. The pump is working just fine, so perhaps relocation/replacement of the tank would suit my purposes, providing me the space I need where I need it. I can think of a location or two that might work...

PorFin · #8 (**permalink**) 10-26-2010

Jos,

Here's a tip on recharging the accumulator tank: Kill the power to the pump, then open a faucet to let the system drain all current pressure. Leave the faucet open, then start pumping air into the accumulator tank with a bicycle pump (we've got one of those 12v auto emergency air pumps that works like a champ.) You should then see or hear more water coming out of your faucet as the water stored in the tank flows out. Once the water stops, and the tank gets up to the proper air pressure, then close the faucet and turn your water pump back on. It should run for a short burst then stop once all your water lines equalize.

scottyt · #9 (**permalink**) 10-26-2010

my boat has a home made acculator. I made it, it is made out of a 2 inch pvc trap with a drain on the bottom. I screwed in a hose barb in to the drain, then extended the sides up about 6 inches and capped them off. it holds about 6 cups of air, and will let me get about 3 cups of water with the pump off. now i do once or twice a season have to pull the hose off the barb and let it refill with air, but i can live with that for the cost of about 5 bucks.

yes they make a lot of difference, as with out the air tank my pump cycles every 3 or 4 mins, with a new pump ( ie the pump does no lose pressure ), with it cycles every 2 hours or so.