On 19/07/2011 23:43, Andy Dingley wrote:
Where is there a drop in pressure (required) where either (one of
which is also required) such a pressure drop approaches below
atmospheric pressures, or else the temperature is approaching the
steam temperature of the boiler?

There is a drop in pressure where the liquid accelerates on entering the
pump. According to Bernoulli's law, when a fluid speeds up its pressure
drops.

--
Jeremy Double {real address, include nospam}
Rail and transport photos at
http://www.flickr.com/photos/jmdoubl...7603834894248/