Forest Girl
Well-Known Member
Mine is the 1 litre model. It leaks from the joint where top half meets bottom half. Is a new gasket available and if so, where from? Thanks everyone. All advice gratefully received.
Jabsco accumulator tank repair
- Thread starter Forest Girl
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charles_reed
Well-Known Member
If it's leaking it hasn't been working for a long time. "Repair" after this length of time isn't really an option.
The accumulator, has a rubber bladder inside, under pressure from (usually nitrogen) from the gas around it in the main chamber - if you look at the top there is a Schrader valve with which you should top up the pressure on the bladder (to vary the water pressure in your system).
I'd suggest you order another, fit that (it's a simple screw-off and then on) and, in future check the pressure in the unit at least annually. Failure of the bladder usually occurs when the atmosphere inside the unit drops low enough for the bladder to touch the side of the container. From memory the 1-litre "Mini-Par-Mate" has been long-since discontinued but have a look on this site www.jabscoshop.com/spare-parts/
Space to fit the replacement would be the biggest concern, I believe the screw-fitting is the same. When mine went I replaced the whole unit as the built-in pressure switch also packed in and couldn't be replaced.
They're usually expensive, but reasonably good service - once you've ascertained what you want I'd order from ASAP Supplies.
NormanS
Well-Known Member
Don't know, but it might well be a simple "O" ring. Take it apart and have a look. Rubber O Rings are widely available from engineers suppliers.
Marsupial
Well-Known Member
The jabsco stuff is very expensive, you could fit one of these if you have the space (dont worry about the volume - it will work)
http://www.ebay.co.uk/itm/2-litre-a...tEquipment_Accessories_SM&hash=item2a2c5b2afd
superheat6k
Well-Known Member
vyv_cox
Well-Known Member
My previous motorhome had an accumulator like that one, or maybe even smaller and cheaper, in a system that was pretty much identical to a yacht one. It used a Par Max3 pump, galley, heads and shower hot and cold supplies. Perfectly OK.
David2452
Well-Known Member
The plastic one is probably fine, but anything red is not for potable water, they are used in hot water systems and heating.
NormanS
Well-Known Member
Well, the one in my boat with a Johnson pump is red. It would be installed when the boat was built in 1992. Maybe the colour convention is a later development?
David2452
Well-Known Member
All sorts of stuff gets fitted to boats and I doubt there is a convention as there are no regs so you can do much as you like, I will only use WRAS vessels for potable water, they are often silver or white but the WRAS approval is the main consideration.
Edit for pedantry, when I say WRAS I mean WRAS approved for potable water.
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l'escargot
Well-Known Member
The older 1 litre Jabscos didn't have a membrane but couldn't be dismantled so if it is leaking it is a replacement job as well.
Marsupial
Well-Known Member
David2452
The plastic one is probably fine, but anything red is not for potable water, they are used in hot water systems and heating.
coo
I thought they were red because they were under pressure.
I ve only ever seen red ones on domestic water supplies, heating system expansion vessels (they have a different pressure rating but I am sure its just a label) and boats and caravans. And out here, Turkey, they are widespread as many homes run on well water with a pump and accumulator.
And since when has a hot water system not been part of a potable water system?
BUT I do admit to being out of the HVCA (B&ES) industry since 1988 I agree things change and paint manufacturers must have a field day.
The plastic one is probably fine, but anything red is not for potable water, they are used in hot water systems and heating.
coo
I thought they were red because they were under pressure.
I ve only ever seen red ones on domestic water supplies, heating system expansion vessels (they have a different pressure rating but I am sure its just a label) and boats and caravans. And out here, Turkey, they are widespread as many homes run on well water with a pump and accumulator.
And since when has a hot water system not been part of a potable water system?
BUT I do admit to being out of the HVCA (B&ES) industry since 1988 I agree things change and paint manufacturers must have a field day.
David2452
Well-Known Member
Never to my knowledge, I meant hot water heating systems, Turkey is hardly a shining example of regulation (or it's enforcement anyway
) and not even part of the EU.
nigelmercier
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Anyone care to explain how they work? I thought I had an accumulator, but I suspect it is just a device to keep the pump primed. [Later] It's a Comet Pressure Equalizer: http://i77.photobucket.com/albums/j...81a74239b89cb95dde13_zpsa4631836.jpg~original
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concentrik
Well-Known Member
My (jabsco) unit exploded. Black plastic shards in every corner of the lazarette. I didn't have a replacement handy, nor could I find one locally so I just linked the hoses.... and so it has stayed for the last year. The H&C works perfectly well without it, no 'cycling', so I'm not sure what it was doing in the first place!
vyv_cox
Well-Known Member
They rely on the fact that whereas water is effectively incompressible, air is not. Water pressure from the pump enters the accumulator downstream of it and compresses the air above the water, or the membrane, assuming the tap is closed. When the tap is opened the air expands, driving water out until the pressure falls below the set pressure on the pump switch. Overall effect is to smooth the flow and avoid the pump cutting in for every drip of water.
nigelmercier
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- Live in Kent, boat in Canary Islands
Thank you. So they don't necessarily have a means to compress the air manually?
I've put a link to a picture in my question above. Is this an accumulator? If so, they are pretty cheap at a caravan shop.
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vyv_cox
Well-Known Member
Yes, that's the simplest type. No diaphragm, which means they have to be mounted as shown. The ones with a Schrader valve are usually the diaphragm type. The valve allows a little more tuning than your version but essentially both will work equally well.
David2452
Well-Known Member
The one in the picture has (seems to have) no means of matching the accumulator pressure to the system pressure so not so much use as a true accumulator and more a "smoother" , mind you most proper ones are not adjusted annually or indeed on installation to the correct pressure anyway, so probably no matter anyway. I have yet to find one adjusted correctly on a service visit and they might as well not be there, well almost. The accumulator should be set at around 3PSI below pump cut out pressure and that should be done with no pressure in the water system, preferably with Nitrogen s that is what is in most potable accumulators ex factory.
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charles_reed
Well-Known Member
The ITT units are quite sophisticated - nothing like the units being demo'ed in this thread. I've had quite a few "run-ins" with boat pressurised water systems and having a genuine accumulator makes a tremendous difference to showering and reduces the pump running time. However it will always work without one in the circuit.
I've found that 1.2bar on the system filled, gives the best result - as it's interdit to take a pressurised vessel on an aircraft, I've always had to empty and then pump them up. Regular servicing is a must. I live on the boat 6/12 of the year and check the pressure on arrival and before leaving (x2 a year).
The last accumulator I bought (admittedly trade) cost me <£20 and is well worth that price in making sure the hot/cold water mix is right.
David2452
Well-Known Member
Indeed, the right size, correctly matched to the pump pressure bears no relation to the undersized, mal adjusted bits of kit found aboard most boats, as I wrote earlier, they may almost as well not be there, OK they stop a bit of cycling but not the job they really could do.
