Long & thin goes too far in & doesn't please the ladies,
Short & thick just does the trick for manufacturing babies!!!
Why are all expansion vessels so cr#p!!
- Thread starter Richardthe3rd
- Start date
Long & thin goes too far in & doesn't please the ladies,
Short & thick just does the trick for manufacturing babies!!!
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Who knows in the future there is a different material better than rubber, rubber is porous
Boiler and vessel manufacturers are a clueless bunch....these calculations are wrong in that they assume a high hot working pressure is acceptable....they make no allowance for the drop in air/nitrogen charge over the course of a year of 2 between checks. There's also no allowance made for the setting of a higher than ideal cold pressure due to misunderstanding by users.
Say for instance your cold pressure is 1 bar. For a reliable and sensible pressure increase I size the vessel for no more than a 0.5 bar increase when hot. Then the system is not subjected to a high fluctuation in pressure each time the heating's on and there is a significant margin left (between hot working pressue and the safety going off) as the vessel loses air over the course of a year or 2 before vessel re-charging.
It's now become a joke with manufacturers sticking 6 litre vessels in their boilers. Hot pressures are going well beyond 2 bar and if the vessel is not checked each year there's a good chance of the safety opening after just a couple of years. In addition it only takes a user (and plenty of installers) overpressurising through lack of understanding and the situations even worse.
This is a 15 litre vessel fitted to the Vaillants of 40 odd years ago (the sine). Made by W&P and quality...but nowadays it's no longer acceptable for a boiler maker...it's gotta be cheap cheap cheap so 6 or 8 litres and a diaphragm thick as a balloon.
http://www.boilerparts.co.uk/Uploads/VAILLANT/181001.jpg
Say for instance your cold pressure is 1 bar. For a reliable and sensible pressure increase I size the vessel for no more than a 0.5 bar increase when hot. Then the system is not subjected to a high fluctuation in pressure each time the heating's on and there is a significant margin left (between hot working pressue and the safety going off) as the vessel loses air over the course of a year or 2 before vessel re-charging.
It's now become a joke with manufacturers sticking 6 litre vessels in their boilers. Hot pressures are going well beyond 2 bar and if the vessel is not checked each year there's a good chance of the safety opening after just a couple of years. In addition it only takes a user (and plenty of installers) overpressurising through lack of understanding and the situations even worse.
This is a 15 litre vessel fitted to the Vaillants of 40 odd years ago (the sine). Made by W&P and quality...but nowadays it's no longer acceptable for a boiler maker...it's gotta be cheap cheap cheap so 6 or 8 litres and a diaphragm thick as a balloon.
http://www.boilerparts.co.uk/Uploads/VAILLANT/181001.jpg
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Simplistic answers are generally wrong or at best incomplete.
Of course manufacturers want to make boilers and sell them but you can't buck the market which knows the price of everything but not the value.
All you have to do is make a two and a half grand boiler that lasts for 30 years and find enough people to buy it and get it put in and serviced properly.
If boilers are crap it's because it's a cr*p world.
Of course manufacturers want to make boilers and sell them but you can't buck the market which knows the price of everything but not the value.
All you have to do is make a two and a half grand boiler that lasts for 30 years and find enough people to buy it and get it put in and serviced properly.
If boilers are crap it's because it's a cr*p world.
This may have something to do with running acidic water through them. Imagine how long hi-fi or digital cameras would last if they had to be condensing.
My world is far from cr.p matey. You speak for yourself!!
That's got to be one of the daftest comparisons I've heard in a long time.
It's not a comparison you b*rk.
I do speak for myself and I read what you write, your opinions and comments; your world does not seem that far from crap, perhaps it commutes to here
Trying to get back to basics!
The manufacturers design their boilers for a typical smaller three bed semi with a heat loss of about 8-9 kW average heat loss.
At the correct low water content radiators for that power output the smaller expansion vessel is quite adequate. That keeps the boiler price down and gives a competitively priced product.
The manufacturers make it very clear that in some cases an additional external vessel is required.
But few installers ever read the instructions or even consider if an additional vessel is needed and certainly don't price for one.
The old Sine 18 is rather amusing to me because its odd design creates a boiler which can carry on working to an extent with several faults. Most of those which I go to repair have more than one fault.
Even the Response 80/120 will provide DHW when the DHW flow switch has failed if the CH is turned on.
Tony
The manufacturers design their boilers for a typical smaller three bed semi with a heat loss of about 8-9 kW average heat loss.
At the correct low water content radiators for that power output the smaller expansion vessel is quite adequate. That keeps the boiler price down and gives a competitively priced product.
The manufacturers make it very clear that in some cases an additional external vessel is required.
But few installers ever read the instructions or even consider if an additional vessel is needed and certainly don't price for one.
The old Sine 18 is rather amusing to me because its odd design creates a boiler which can carry on working to an extent with several faults. Most of those which I go to repair have more than one fault.
Even the Response 80/120 will provide DHW when the DHW flow switch has failed if the CH is turned on.
Tony
I do speak for myself and I read what you write, your opinions and comments; your world does not seem that far from crap, perhaps it commutes to here
Well, if your life is crap; stop writing sh.t on dead beat forums, get out more & change you crappy life. There's a wonderful world out there just waiting for you son, go & grab some!!
I'm not the tw.t that wrote the drivel, you are!!
No, so that makes you just the tw*t then.
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