Indirect tank fed cylinder installation

[pistonbroke1957]

I came across one of the above yesterday and there does not appear to be an open vent.
The cylinder is fed from a tank approx 12 metres above the cylinder in a separate building.
There is an A.A.V. and P.R.V on top of the cylinder.
Have never seen an installation like this before as it just doesn't look right to me.
A. Has anyone seen an installation like this before.
B. Can a new cylinder be installed with the same pipework configuration.

 

[CBW]

Are you sure it’s not an unvented cylinder? Is the tank still live and connected?

 

[pistonbroke1957]

chris.
The tank is live and connected and the cylinder is definitely tank fed as there is no mains cold water supply in the plant room

 

[fixitflav]

Can a new cylinder be installed with the same pipework configuration.

If the system has worked OK till now, I don't see why not. Usually there is a vent pipe opening over the cold water tank, but somebody has saved some pipework by using an AAV instead. Of course a new cylinder has to be good for the 12m head, and the PRV set pressure, preferably with a margin. Just had a quick look on the web and the first one I saw was for 10m maximum.