On Jul 19, 10:21*am, Andy Dingley wrote:
On Jul 18, 8:07*am, harry wrote:

There is a problem with all boiler feed water pumps and that is
cavitation.

Utter ********. Cavitation is a problem of _low_ pressure in pumps,
sufficient to form bubbles (i.e. "cavities"). *The one thing we know
about a boiler feedwater pump of any form is that it has to work at
around boiler pressure. Whilst the Giffard injector stops working with
hot water, heat isn't a big problem for pumps.

Well old son I ran steam boilers for thirty years with many sorts of
boiler feed pumps. I have seen all manner of mishaps and failure.
The cavitation takes place on the suction side of the pump as even a
half wit such as yourself would realise with a momentst hought.
Cavitation is the commonest reason for boiler feed pump failure.
The pressure it works at depends on the control system for boiler
water level but often rises very considerably above boiler pressure.
You only theory men need to keep quiet.