Loathed or not they appear to consider it necessary to include anti vac in their system. How many other manufacturers include anti vac ?. Maybe it is mandatory to provide an anti vac function in an unvented cylinder and it just isn't mentioned.
Vented / unvented cylinders, pros and cons
- Thread starter bernardgreen
- Start date
Loathed or not they appear to consider it necessary to include anti vac in their system. How many other manufacturers include anti vac ?. Maybe it is mandatory to provide an anti vac function in an unvented cylinder and it just isn't mentioned.
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Face it Bernard. You've dig yourself yet another hole.
A cylinder rated to 8 bar or more is hardly going to develope a vacuum big enough to collapse it.
Anyway... How addressing all the other issues you are ignoring despite your protestations.
Face it Bernard. You've dig yourself yet another hole.
A cylinder rated to 8 bar or more is hardly going to develope a vacuum big enough to collapse it.
Anyway... How addressing all the other issues you are ignoring despite your protestations.
8 bar is the rating for positive pressure.
Positive pressure tries to expand the cylinder, the wall are being stretched, they will not therefor crumple.
Negative pressure tries to contract the cylinder, the walls need to shrink, they will bend inwards .
I do not know the negative pressure that will cause a cylinder to start to crumple inwards. I suspect for a copper cylinder it is far less than the positve pressure rating.
My apologies, I received the document and URL in an e-mail.
The bold print added hidden formatting charactors. try http://lomaxtraining.co.uk/ and search the site.
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Have you compared deflection pressures of the two?
Takes a fair bit in a SS Unvented.
Without evidence of collapsing cyclinders, or plausible examples if what would cause it, I call it as a null argument.
However, on cylinders with internal air bubbles, having draw offs significantly below the cylinder can cause the air to be depleted by syphonage.
Takes a fair bit in a SS Unvented.
Without evidence of collapsing cyclinders, or plausible examples if what would cause it, I call it as a null argument.
However, on cylinders with internal air bubbles, having draw offs significantly below the cylinder can cause the air to be depleted by syphonage.
QUOTE from Solfex installation guide.
Anti Vacuum Valve
Important
- failure to follow the drain down procedure will invalidate the waranty.(see page 22)
NEVER
drain the cylinder of hot water and then close all cylinder inlets and outlets.
REASON
as the air remaining in the cylinder cools the pressure inside the cylinder will fall below atmospheric and cause the cylinder to implode.
NEVER
close the cold main and drain the cylinder via any tap connected to it.
REASON
as the water drains, the pressure inside the cylinder may decrease below atmospheric and this will cause the cylinder to implode.
To stop the possibility of this occurring by accident an ANTI VACUUM VALVE should be fitted in the hot water take off pipe.
This will balance the cylinder’s internal and atmospheric pressures and eliminate this risk.
Available from Gledhill part number GT056
End Quote
by e-mail from an owner of a Solfex cylinder.
Is the fitting of an anti vac valve a requirement of BS12897 or just a manufacturer's application of science and common sense
Anti Vacuum Valve
Important
- failure to follow the drain down procedure will invalidate the waranty.(see page 22)
NEVER
drain the cylinder of hot water and then close all cylinder inlets and outlets.
REASON
as the air remaining in the cylinder cools the pressure inside the cylinder will fall below atmospheric and cause the cylinder to implode.
NEVER
close the cold main and drain the cylinder via any tap connected to it.
REASON
as the water drains, the pressure inside the cylinder may decrease below atmospheric and this will cause the cylinder to implode.
To stop the possibility of this occurring by accident an ANTI VACUUM VALVE should be fitted in the hot water take off pipe.
This will balance the cylinder’s internal and atmospheric pressures and eliminate this risk.
Available from Gledhill part number GT056
End Quote
by e-mail from an owner of a Solfex cylinder.
Is the fitting of an anti vac valve a requirement of BS12897 or just a manufacturer's application of science and common sense
None of that has anything to do with operational failure.
Which is your whole reason for disliking them.
Which is your whole reason for disliking them.
It also implies the anti Vac valves are not fitted as standard.
The amount of safety equipment necessary and the need to ensure that safety equipment will operate when necessary is a big dis-advantage when compared to the inherently safe vented system.
But if the manufacturer of a stainless steel ( the more robust ) cylinder make a point of recommending them ?
Do you have a copy of BS EN 12897, does it refer to the fitting of anti vac valves ?
I don't as it happens. But if it was required it would be sold with the cylinder as with all the other safety devices REQUIRED.
If it was a requirement, it would have been made more prominent in all the other manufacturers literature.
Certainly was not brought up in any of the exams or training I have attended in the 15 years I have been G3 certified .
If it was a requirement, it would have been made more prominent in all the other manufacturers literature.
Certainly was not brought up in any of the exams or training I have attended in the 15 years I have been G3 certified .
Not mentioned in OSO literature.
Not mentioned in stelflow literature.
Not mentioned in Vaillant literature
Wow.... It is mentioned in Albion literature...
Which is common sense and not to do with imploding tanks.
Which is common sense and not to do with imploding tanks.
Not mentioned in any Heatre Sadia literature.
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