On Jul 26, 7:39*pm, "Dave Plowman (News)"
wrote:
In article
,
* wrote:

Since a pressure vessel isn't exactly rocket science, is this the case?
Header tanks *- or rather the ball valves - do give trouble too.
Pipework is pressurised, so more prone to leaks.

So your cold water main leaks? *Oh - a header tank system is pressurized
too by the head of the tank.

Open headers can be turned down to a slow dribble, yes they can
overflow, but it doesnt stop the system working and an exterior
dribble is not too urgent to fix.

The point was if you have a leak the open system will continue to supply
water for that leak - the pressurized one can't.

You said that in the last post. And I then said...