DHW cylinder

[BH]

Have finally said good-bye to Tony blair to come and live in Italy, so i am renovating an old barn here.
I have put in a double coil cylinder for wood stove and solar, the cylinder is heavy gauge steel to 8bar.
With the wood stove I am obviously having open vented system but here they tend not have cold water supply tanks...its straight of the mains.
Can any one tell me is it ok to plumb the mains straight into the cylinder or does the mains pressure keep pushing water out of the cylinder vent?

Many Thanks
Brian, sitting on terrace in sun shine

 

[chrishutt]

If the tank is rated to 8 Bar, it must be OK for normal mains pressure, but you need to check on Italian regulations for such things. I Doubt if uncontrolled heat sources can be connected to an unvented cylinder.

 

[Paul Barker]

I seem to remember from my unvemted notes that they have a different attitude on the contenent. They deal with expansion with temperature by letting it flow out via the tundish from the expansion valve. You will have to check local rules about qualifications and standards, but you could be right.

 

[BH]

If the tank is rated to 8 Bar, it must be OK for normal mains pressure, but you need to check on Italian regulations for such things. I Doubt if uncontrolled heat sources can be connected to an unvented cylinder.

Cheers for that but think I might have misled you.
The cylinder will be vented but need to know mains straight in is ok or hase to have cold feed tank
Cheers

 

[silverback]

You can not have a vented mains fed cylinder, a mains fed cylinder is a closed system, with expansion vessel and safety devices, if you are having a vented cylinder it has to be tank fed, there is no other way.

 

[Paul Barker]

I don't think they use expansion vessels on the continent, just let he expansion leak out, less concerned about water wastage over there. But agreed an open vent on a mains fed cylinder is a fountain.

 

[BH]

You can not have a vented mains fed cylinder, a mains fed cylinder is a closed system, with expansion vessel and safety devices, if you are having a vented cylinder it has to be tank fed, there is no other way.

Thanks very much silverback

 

[slippyr4]

You can not have a vented mains fed cylinder, a mains fed cylinder is a closed system, with expansion vessel and safety devices, if you are having a vented cylinder it has to be tank fed, there is no other way.

Not if your vent pipe is very very long!!!!

 

[silverback]

About the height of the Empire State Building might do it

 

[chrishutt]

443 metres? No way, a vent pipe of 50 metres would suffice for mains pressure of 5 Bar. Just use galvanised cables anchored to concrete bases to stabilise it in high winds.

 

[meldrew's_mate]

443 metres? No way, a vent pipe of 50 metres would suffice for mains pressure of 5 Bar. Just use galvanised cables anchored to concrete bases to stabilise it in high winds.

That seems a bit silly, if you're going to go to the trouble of installing stabilising cables why not do the job properly and put a CWS tank up there too. I'd probably try to recoup the expence of this by selling space on the supports to mobile phone co.s, especially if it's in a mountainous region.

Seriously though, don't forget to buy high pressure taps, and change the bog nozzle(s)