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Topic: Water Pump Accumulator Tank (Read 2162 times) previous topic - next topic

Water Pump Accumulator Tank

Having problem with my pump pulsating.  My assumption was no pressure on my accumulator tank.  I checked the tank pressure with a gauge and nothing.  I depressed the valve core and no air no water.  I removed the valve core and it came out in pieces.  With the pump on I used a small left hand drill and drill into the valve to snag any remains.  With the water pressure and the drilling the pieces came out along with tons of water.  I need to replace the tank. I found the Flojet tank tank from as low as $129 to over $200.  I found this accumulator tank through Walmart online at a great price.  It has a mounting base and will work great with a little hose modification.  The new tank is 1/2"npt and the old tank is 1/4"npt.


[fixed spelling error in title to help future searches  - Michelle]
John & Carm Morales

"We travel not to go anywhere, but to just go.  We travel for travel's sake.  Our great desire is to move."

Re: Water Pump Accumalator Tank

Reply #2 –
As long as it has a bladder, that tank will be just fine.  Set it to CUT-IN PSI minus 2 PSI with water pump off and system depressurized (open a faucet).  So, for most OE pumps about 23 PSI.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Water Pump Accumalator Tank

Reply #3 –
Brett, the tank is a
2 gallon 1/2" Female NPT
FDA Approved Rubber Diaphragm
Custom Wall Brackets Included
Applications
Residential Water Heaters
Water Storage Application Reverse Osmosis Expansion Tank
Max Liquid Pressure: 130 PSI Pre-Pressurized Air: 30 PSI
So are you saying I need to reduce the pressure from 30 PSI to about 23 PSI?
Thanks, John M
John & Carm Morales

"We travel not to go anywhere, but to just go.  We travel for travel's sake.  Our great desire is to move."

Re: Water Pump Accumalator Tank

Reply #4 –
Quote from: John Morales –
So are you saying I need to reduce the pressure from 30 PSI to about 23 PSI?
Thanks, John M

If your water pump has a cut in PSI of 25, then, yes 23 is the right PSI. Verify for your pump PN.

And, if it has been replaced with one of the new variable speed pumps they do not play well with accumulators, so none are needed.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Water Pump Accumalator Tank

Reply #5 –
Agree. My tank was set from factory at 50 psi, my pump shuts off at 48, so short cycled just like I did not have a tank. Bleed off to 40, now 10 to 20 seconds before pump comes on again.
Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.

Re: Water Pump Accumalator Tank

Reply #6 –
Quote from: wolfe10 –

And, if it has been replaced with one of the new variable speed pumps they do not play well with accumulators, so none are needed.


Variable speed pumps work fine with pressure tanks, if they are not used as pressure tanks LOL. I pressurized mine to ~85PSI. It then allows for expansion of heating water and prevents the hot water heater from "weeping" out the safety relief valve. I think my pump goes to around 75psi
1998 U270 34'

Re: Water Pump Accumalator Tank

Reply #7 –
Quote from: wolfe10 –

new variable speed pumps they do not play well with accumulators, so none are needed.


Please explain, are not needed is technically correct. but still beneficial as even variable speed motors have a typicaly have a minimum cooling rpm and short cycling is the number one cause IMO, of motor overheating and failure. I do not get the reasoning behind the "play well together" either.
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake

Re: Water Pump Accumalator Tank

Reply #8 –
Brett,
My pump has a cut in at 20 PSI 40 PSI cut out, so I need to set the tank pressure to 18 PSI to accomadate my cut in pressure.

Thanks, John M.
John & Carm Morales

"We travel not to go anywhere, but to just go.  We travel for travel's sake.  Our great desire is to move."

Re: Water Pump Accumalator Tank

Reply #9 –
Quote from: Old phart phred –
Please explain, are not needed is technically correct. but still beneficial as even variable speed motors have a typicaly have a minimum cooling rpm and short cycling is the number one cause IMO, of motor overheating and failure. I do not get the reasoning behind the "play well together" either.


It actually makes it worse. As pressure increases with the pump charging the accumulator, the pump slows and slows and slows and then runs a bit at super slow. With no accumulator, the pressure spikes quickly and the pump shuts off instantly.
1998 U270 34'

Re: Water Pump Accumalator Tank

Reply #10 –
My tank rusted through and leaked water - got a new one at Homedepot for 35usd. Works perfectly. I set prepressure just below the activation pressure of the water pump.

Cheers, Matt
1998 U270 3402 WTFE #5260
Cummins 8.3l - Allison MD3060
600W Solar :P

Re: Water Pump Accumalator Tank

Reply #11 –
Quote from: krush –
It actually makes it worse. As pressure increases with the pump charging the accumulator, the pump slows and slows and slows and then runs a bit at super slow. With no accumulator, the pressure spikes quickly and the pump shuts off instantly.
Thanks Krush, I see your point about flow/pressure spikes happening very quickly in a RV and there relationships with the variable speed pressure regulated pump. So I retract my statement about a accumulator tank being beneficial. Thanks as you and Brett are correct.
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake

Re: Water Pump Accumalator Tank

Reply #12 –
I installed a Shurflo 4008 not too long ago.  It is not a variable speed pump.  The instructions said a pressure tank was not required, so I initially hooked it up without the tank.  It worked fine, but since it comes on every time you use water, it "sounded" to me like it was working way too hard.  I then reconnected the pressure tank, and the pump operation seems a lot more "relaxed".  You can use the bathroom sink/flush the toilet in the middle of the night, and the pump (usually) does not have to instantly kick on.

Note:  I will add that when this pump does run, it is WAY quieter than our older pump.  A significant improvement in noise level!

The tank may not be required (with the 4008), but I prefer having one in the system.  I moved mine from the water pump bay to inside the coach, under the bathroom sink.  Gives me more room to work around the pump and watch for leaks in the bay.  8)
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Water Pump Accumalator Tank

Reply #13 –
Just installed a 4008,called Shurflo tech service just to verify the tank not needed.Will run pump without tank for now,the less connections the better.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Water Pump Accumalator Tank

Reply #14 –
Quote from: Chuck & Jeannie –
I installed a Shurflo 4008 not too long ago.  It is not a variable speed pump.  The instructions said a pressure tank was not required, so I initially hooked it up without the tank.  It worked fine, but since it comes on every time you use water, it "sounds" to me like it is working way too hard.  I then reconnected the pressure tank, and the pump operation seems a lot more "relaxed".  You can use the bathroom sink, or flush the toilet in the middle of the night, and the pump (usually) does not have to instantly kick on.

Note:  I will add that when this pump does run, it is WAY quieter than our older pump.  A significant improvement in noise level!

The tank may not be required (with the 4008), but I prefer having one in the system.  I moved mine from the water pump bay to inside the coach, under the bathroom sink.  Gives me more room to work around the pump and watch for leaks in the bay.  8)
Chuck..What size tank did you use under the sink.??? Any pics.??

Thx
Hans
Hans & Marjet
1995 U300 "Ben" (#4719)
3176B Cat,4060HD,Jake
SKP#139131
Motorcade#17579
2006 Honda Element (towed)

Re: Water Pump Accumalator Tank

Reply #15 –
Quote from: Hans&Marjet –
Chuck..What size tank did you use under the sink.??? Any pics.??
I used the tank that came in our coach when we bought it (3 years ago).  It was new at that time, and is still in good shape.  It is a Jabsco model 18810-0000 2 gallon bladder tank.  I made up a little aluminum bracket to "hang" the tank from the shelf under the sink.  Big band clamp goes around the tank and the water lines to help stabilize it, as does the (removable) piece of white foam.  Tied into the cold water line with SharkBite fittings.  In this position, I can still access the air valve on the bottom to check/add air.  The tank uses some formerly "unused" space, so worked out nicely.

JAB 188100000 Jabsco 18810-0000 2 Gallon Accumulator Tank - Water & Pressure...

One photo shows our now "wide open" water pump bay - much easier to work in there.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Water Pump Accumalator Tank

Reply #16 –
Ditto on tank from HomeDepot.  Replaced two years ago with no problems.
Tom and Linda
1995 U280SE #4636

Re: Water Pump Accumalator Tank

Reply #17 –
The next time someone has to replace a tank get the water worker tan tank for hot water, it has a different bladder and will last longer, the tank not only helps keep pressure on the system, it also takes care of the water expansion from the water heater.
The selected media item is not currently available.Bill&Doris 97 U270 36'
University of Parris Island Class of 66
Semper Fi  Build# 5174 MC#17094

Re: Water Pump Accumalator Tank

Reply #18 –
I have a WELLSAVER Model LET2 that is near new left over from my FT days.  If anyone can use it especially if you are in the ATL area its yours for the asking. When I replaced a pump in one of my FT's it was too large to fit in the space so I removed it although I had jest replaced it not long before.

Gary B