Accumulator tank info

[Alan de Enfield]

1 minute ago, magnetman said:

 

 

There is an option to ask questions on the midland Swindlers site. I wonder if the question "Excuse me sir/madam, could you please tell me whether the water inside this is in a rubber bladder or contained within the metal shell." would be met with a knowledgeable response. 

 

I'm sure if you spoke to the manufactures 'customer services' they'd help - would you expect to go intom Tesco (other supermarkets are available) and ask a similar technical question ?

[magnetman]

18 minutes ago, rusty69 said:

Tracy is knowledgeable, and has already stated what the answer is. 

 

Is the Jabsco item the one mentioned in the original question? I just added it as a piece of randomly available marine equipment. 

 

 

[rusty69]

3 minutes ago, magnetman said:

 

Is the Jabsco item the one mentioned in the original question? I just added it as a piece of randomly available marine equipment. 

 

 

I don't know what type it is. Probably @carp-addictis the best person to ask. 

[magnetman]

I don't see how one can find out the type without cutting the thing open anyway. It seems to be an impossible thing to judge. 

 

 

[rusty69]

Maybe an xray. 

[magnetman]

I've got x-ray specs somewhere but I don't think it goes through enamel or steel. 

 

Some random YouTube person needs to get one of this and put a saw on it. 

 

 

Drill a very small hole near the bottom of the tank and see if air or water comes out. If it is air then it must be a bladder with water in it. If it is water then the water must be contained in the steel shell. 

 

I'm still intrigued about the potable and non potable situation if the water is in a bladder.  

[rusty69]

I nominate you for the job. 

[Tony Brooks]

14 minutes ago, magnetman said:

 

Is the Jabsco item the one mentioned in the original question? I just added it as a piece of randomly available marine equipment. 

 

 

 

Or even non-marine equipment. I am sure Tracy is correct in the majority of cases, especially those with the inlet fitted into what looks like a screw on cover plate, but I am sure I have seen ball-shaped one with the two halves apparently swaged together. that suggest to me they have a diaphragm between the two halves so the water is not inside a bladder.

 

I think potable types use an HDPE bladder or some such group of letters, rather than straight rubber.

[MtB]

2 hours ago, Tracy D'arth said:

To be completely clear, there should never be any water in the steel can. All the water is contained in the rubber bladder and the air between can and bladder controls the inflation of the bladder by the water pump. You will find contradictory information which is wrong.

 You need a new accumulator. 

 

Meanwhile over in "The Combustion Chamber" forum for registered gas engineers, the arguments about this grumble on bad-temperedly. Some hold as you do, the water is always in the bladder, others hold that both types are available. Still further there is a skool of thought (held remarkably aggressively by some) that in 9 out of 10 cases of water coming from the valve it is residual condensation, and if it must simply be drained out and the vessel re-pressurised and put back into service. This camp holds that most pressure vessels are replaced needlessly by fools who don't understand how they work.

 

Moving on, some are made with removeable bladders. They have a plate with a ring of bolts around the water connection. Others have a diaphragm in the centre and can be identified by a crimped band around widest part of them. Still more have the two halves welded together and no obvious way of getting the bladder in. One day when I get a round tuit, I'll slice a few dead ones open for a proper look.

 

 

[Tony Brooks]

27 minutes ago, MtB said:

Still further there is a skool of thought (held remarkably aggressively by some) that in 9 out of 10 cases of water coming from the valve it is residual condensation, and if it must simply be drained out and the vessel re-pressurised and put back into service. This camp holds that most pressure vessels are replaced needlessly by fools who don't understand how they wor

 

Well, yes, that would work for a while. It is just replicating a bladder/diaphragm free version for a while. I am sure there have been bladder/diaphragm free versions sold into the marine trade, but usually very small ones and part of a pump package. I have also heard of people doing Bizzardesque things like using old pop bottles as an accumulator with just air at the top of the inverted bottle.

Edited January 21, 2023 by Tony Brooks

[rusty69]

Bizzardesque would make a fantastic addition to the English language. 

 

It would need a definition though. Preferably including the word meccano. 

Edited January 21, 2023 by rusty69

[carp-addict]

For what its worth heres a pic of the tank

 

As there is no writing on I am unsure what the size is  

Measurements are approx 17cm width 28cm

 

 

[carp-addict]

Thinking  this may be ok as a replacement

 

https://www.toolstation.com/expansion-vessel-potable/p41665?utm_source=googleshopping&utm_medium=feed&utm_campaign=googleshoppingfeed&mkwid=_dc&pcrid=&pkw=&pmt=&gclid=Cj0KCQiAt66eBhCnARIsAKf3ZNFfTvVjdBVpUkHq8tI_jFLTdK5GTtY2MPIHtxtF8KTQtlM56c9Ob-caAm13EALw_wcB&gclsrc=aw.ds

 

Thoughts ?

[Tony Brooks]

Yes.

[system 4-50]

I tested my house accumulator and water came out.  I decided the diaphram had failed so I replaced the accumulator.  When I took the old one off, a ton of rusr came out and the rubbery bit was found to be spilt. No condensation was apparent.

[carp-addict]

44 minutes ago, Tony Brooks said:

Yes.

Thanks Tony

[Tracy D'arth]

Clarification.

 

There are bladder and diaphragm types.

Most of the bladder ones have a bolted flange at the bottom, water connection, end and in theory you can replace the bladder. In practice it is pointless as if the bladder has failed there is water in the steel can which will be rusting away. Its probably not cost effective either, even if you could find a new bladder. All the water should be in the bladder. Air in the can.

 

The diaphragm ones are generally bigger sizes and intended for sealed pressurised central heating systems, usually red painted.

There may be a definite welt around the middle where the diaphragm is attached.

OR

They are small round stainless steel items intended as shock arrestors on cold water systems . Similar construction

All the water should be under the diaphragm. Air above in the can.

 

Neither types are exclusive, there are cross overs in construction and use.

 

Potable water ones have the correct rubber composition for potable water, usually HDPE. Heating system ones may not be so.

The can does not need to be stainless steel.

 

However, categorically, if there is water coming out of the air valve the rubber has failed, end of.

 

Then there is the simple plastic air bottle which may or may not have an air valve, has no rubber inside. Usually quite small and will need removing and emptying occasionally.

[carp-addict]

On 24/01/2023 at 06:39, Tracy D'arth said:

Clarification.

 

There are bladder and diaphragm types.

Most of the bladder ones have a bolted flange at the bottom, water connection, end and in theory you can replace the bladder. In practice it is pointless as if the bladder has failed there is water in the steel can which will be rusting away. Its probably not cost effective either, even if you could find a new bladder. All the water should be in the bladder. Air in the can.

 

The diaphragm ones are generally bigger sizes and intended for sealed pressurised central heating systems, usually red painted.

There may be a definite welt around the middle where the diaphragm is attached.

OR

They are small round stainless steel items intended as shock arrestors on cold water systems . Similar construction

All the water should be under the diaphragm. Air above in the can.

 

Neither types are exclusive, there are cross overs in construction and use.

 

Potable water ones have the correct rubber composition for potable water, usually HDPE. Heating system ones may not be so.

The can does not need to be stainless steel.

 

However, categorically, if there is water coming out of the air valve the rubber has failed, end of.

 

Then there is the simple plastic air bottle which may or may not have an air valve, has no rubber inside. Usually quite small and will need removing and emptying occasionally.

Thank you for taking the time out to explain and I did use your method of taking a little air out until the pump  kicked in.

I have today replaced the accumulator and it did have flanges on the bottom so if needed you can change the bladder, Not very cost effective at all

One removed I put it into the sink to drain out and what was very noticeable was the rubber residue left around the plug hole

Even more alarming was once I started to shake the water out the colour was a brown rusty colour

 

Any how Job Done 

 

Thanks all