"Bob Wheatley" wrote

Yes, Paul's post was factual. But he's not a plumber.

Maybe that's the reason why he was able to see the problem I was having
integrating what I had read (about pipe diameter affecting pressure) with
what I was merely "being told" in black-and-white terms as being otherwise
(without explanation or discussion). The plumbers were completely silent in
response to my implied requests for help in reconciling what they were
telling me, with what I had read and recalled for them, such as, "The
plumber and the plumbing designer rely on the internal diameter of the water
delivery pipes to control water pressure" (Bob Vila). By giving me the raw,
not paternalistically oversimplified, theoretical information [i.e not
merely what the 'doctors' judged to be all that the little 'patient' need
concern himself with] Paul was able to help me make logical sense of what I
was "being told" with respect with what I had previously read.


A plumber knows that it is unlikely that you have a 100' of 1/2" pipe
supplying a tub valve or any other kind of valve. Making his 3 pound
pressure drop a mathematical improbability.
A typical house will have 3/4" or 1" coming from the meter or supply
source and enter the house in those sizes and not reduce until the last 2
or 3 fixtures. Because those fixtures are typically a bathroom there will
"generally" be 3/4" within 20' to 30' of the farthest bathroom in a
typical house. The point being here that increasing the pipe size would
result in possibly a 1 pound pressure drop increase or less. Probably
less. Whatever actual flow rate is gained would not be humanly detectable.

I think Paul's explanation made this quite apparent.

Because the ports in a typical valve are generally only between 1/8" to
1/4" to allow the water to flow through, you can upsize until you turn
green and the weakest link will always be the valve.

It was to clarify specifically just this question that I posted my query
here in the first place.

If you have good pressure everywhere else in the house then you need to
take apart the offending valve and make sure it has no obstructions.
Re-piping is a waste of time, money, and effort unless you know the piping
system is obstructed with some sort of build up.


Was it not you who said that larger pipes will nonetheless deliver greater
volume (providing the corresponding capacity valves, etc.)?

The industry standard (in the states) is 1/2". It works
just fine on every valve I've installed for thirty years.

Yes, that is the industry standard here in Canada too (for houses). But
I've long noticed in commercial buildings (like the hospital where I work)
they have 1" pipes leading directly to things like toilets. These toilets
(without a tank) flush prodigious amounts of water in just a second or two.
Unless there is more to these systems than meets my eye, it would appear to
me that larger diameter pipes do allow more water to get through quicker.

I thought I read in one of the previous posts where someone brought up
your valve. That's the key. If you've tried changing showerheads and/or
removing water savers then I'd recommend that you go out and buy
yourself a brand new Moen pressure
balancing valve and install it. I thought someone else suggested
adjusting your PRV (pressure reducing valve) I have no idea if you
have one or not,


Just the one that reduces/regulates the pressure for the entire
household.


You may want to have a professional look at this.
It would be my number 1 suspect.


Being strapped with paying on a huge mortgage (huge only because entry level
property values are staggeringly high here in Vancouver) while earning only
a very modest income, I just can't afford to hire a reputable plumber for
anything that isn't an emergency. So I have little choice but to just try
my best at being as handy and knowledgeable a 'jack-of-all-trades' as I can
be in responding to my house's needs.

Ken