On 20 Aug 2006 22:15:01 GMT, "Bob Eager" wrote:

On Sun, 20 Aug 2006 22:01:51 UTC, "Alan Holmes"
wrote:


"Graham" wrote in message ...
What are the advantages and disadvantages of gate valves and full-bore
Ball valves for mains water, and isolating parts of a CH system.

A ball valve is to set the level of water in a header tank, a gate valve is
use to shut off or allow a flow of water.

Two completely different uses.

Not the ball valve he means. The construction is similar to the small
service valves one should fit in the feed to things. A rotating
spherical shell in a spherical chamber, with holes that rotate in line
with the pipes to open, and reverse to close.

A "globe" valve in fact. If there is sediment in the water a globe
valve is probably better, since a gate valve may have difficulty
seating properly in the presence of sludge.

--
Frank Erskine
Sunderland