On Fri, 18 Nov 2005 20:00:11 -0500, "Robert11"
wrote:

Hi,

On the inlet cold water pipe to the typical cylindrical, vertical, gas
fired hot water heater:

Are most plumbed in with a globe valve, so the water to it can be completely
shut off ?

I saw a diagram where they said to use a gate valve.
This doesn't make much sense to me, as although a gate valve would allow a
consideably greater flow thru it when wide open (less p drop), the globe
style allows for a full shutoff, if needed.

Our new water heater seems to have a lesser flow thru it than our old one of
ten yrs ago.
Wife is quite upset.
On looking thru the web, I came across this gate valve picture.

So, which style is commonly used for this application, these days ?

Also, are these new heaters supplied with any kind of "Energy-Saving"
restriction like so many newer shower heads ? Any thoughts on why the
thruput flow might be lower on the newer one (same size, different mfg.) ?

Thanks,
Bob

I use ball valves for everything now. I've just found them to be
higher quality and more reliable. Gate valves are intended to be
fully on or fully off. Ditto the other posters comment to put one on
both inlet and outlet.

I have noticed that some gate valves are not "full flow" meaning the
bore through the valve is less than the pipe ID. If this type of
valve was used, that could limit flow, but I doubt you'd notice it if
only one faucet was in use. This is also true of ball valves, you
have to make sure it is a "full flow" type. You can tell just by
sighting through the valve while it is open (before it's installed, of
course). If the bore is more than a little less than the ID of the
pipe, it will restrict flow somewhat.

I am not aware of any flow restrictions in new heaters. If you
notice reduced flow after changing out the heater, it may be that your
aerator screen at the faucet has gotten plugged by "gunk" released
when the piping was disturbed to change out the heater. This is not
unusual when plumbing is disturbed. Try unscrewing the aerators and
cleaning the screens. New heaters often have bits of junk in them from
manufacturing as well, and if the installer didn't flush the tank a
little through the drain, then those bits could be plugging the
screens as well.

HTH,

Paul