Here is a somewhat more esoteric question. I have to snake around some
stuff, and I can do it with two 90 degree elbows, or two "45" degree
elbows. In the end, will using the 45 elbows give noticably increased water
flow? The pipe goes into a shower valve that is 1/2 inch, and the interior
of the valve is even more restricted, so I'm thinking in this case it won't
make any difference.

But out there in the real world where we bend this way and that way, does
it matter how sharp the bend is wrt water volume?

On Feb 10, 4:14*pm, Zootal wrote:
Here is a somewhat more esoteric question. I have to snake around some
stuff, and I can do it with two 90 degree elbows, or two "45" degree
elbows. In the end, will using the 45 elbows give noticably increased water
flow? The pipe goes into a shower valve that is 1/2 inch, and the interior
of the valve is even more restricted, so I'm thinking in this case it won't
make any difference.

But out there in the real world where we bend this way and that way, does
it matter how sharp the bend is wrt water volume?

Don't worry about it.

But I can tell you're an obsessive type, so if you want, you can look
up the equivalent friction loss of a 90 degree and 45 degree elbow
with regard to pipe diameters in a fluid dynamics book at the library
or on Google books if you don't believe me. From what I recall,
neither is significant, and you won't notice a difference.

Worry about low-flow shower heads instead.

On Feb 10, 4:23*pm, mike wrote:
On Feb 10, 4:14*pm, Zootal wrote:

Here is a somewhat more esoteric question. I have to snake around some
stuff, and I can do it with two 90 degree elbows, or two "45" degree
elbows. In the end, will using the 45 elbows give noticably increased water
flow? The pipe goes into a shower valve that is 1/2 inch, and the interior
of the valve is even more restricted, so I'm thinking in this case it won't
make any difference.

But out there in the real world where we bend this way and that way, does
it matter how sharp the bend is wrt water volume?

Don't worry about it.

But I can tell you're an obsessive type, so if you want, you can look
up the equivalent friction loss of a 90 degree and 45 degree elbow
with regard to pipe diameters in a fluid dynamics book at the library
or on Google books if you don't believe me. *From what I recall,
neither is significant, and you won't notice a difference.

Worry about low-flow shower heads instead.

I just happened to have it he Reg 90 degree elbow = 0.92 to 3.6
feet of pipe (depending on joint type geom.)
Reg 45 elbow = .45 to .71 feet of pipe (depending on joint geom.)

I studied this about 25 years ago, when I was taking some
fire protection courses. The 45 are far less restrictive.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Zootal" wrote in message
. 97.131...
Here is a somewhat more esoteric question. I have to snake
around some
stuff, and I can do it with two 90 degree elbows, or two
"45" degree
elbows. In the end, will using the 45 elbows give noticably
increased water
flow? The pipe goes into a shower valve that is 1/2 inch,
and the interior
of the valve is even more restricted, so I'm thinking in
this case it won't
make any difference.

But out there in the real world where we bend this way and
that way, does
it matter how sharp the bend is wrt water volume?

"Stormin Mormon" wrote in message
...
I studied this about 25 years ago, when I was taking some
fire protection courses. The 45 are far less restrictive.

You are aware that the OP is talking about elbows, and not wives, right?
--
EA


--
Christopher A. Young
Learn more about Jesus
www.lds.org
.


"Zootal" wrote in message
. 97.131...
Here is a somewhat more esoteric question. I have to snake
around some
stuff, and I can do it with two 90 degree elbows, or two
"45" degree
elbows. In the end, will using the 45 elbows give noticably
increased water
flow? The pipe goes into a shower valve that is 1/2 inch,
and the interior
of the valve is even more restricted, so I'm thinking in
this case it won't
make any difference.

But out there in the real world where we bend this way and
that way, does
it matter how sharp the bend is wrt water volume?

mike wrote in
:

On Feb 10, 4:14*pm, Zootal wrote:
Here is a somewhat more esoteric question. I have to snake around
some stuff, and I can do it with two 90 degree elbows, or two "45"
degree elbows. In the end, will using the 45 elbows give noticably
increased wat
er
flow? The pipe goes into a shower valve that is 1/2 inch, and the
interio
r
of the valve is even more restricted, so I'm thinking in this case it
won
't
make any difference.

But out there in the real world where we bend this way and that way,
does it matter how sharp the bend is wrt water volume?

Don't worry about it.

But I can tell you're an obsessive type, so if you want, you can look
up the equivalent friction loss of a 90 degree and 45 degree elbow
with regard to pipe diameters in a fluid dynamics book at the library
or on Google books if you don't believe me. From what I recall,
neither is significant, and you won't notice a difference.

Worry about low-flow shower heads instead.

I am cursed with curiosity for just about everything... ggg what if...?
what if ... ? what if ... ?

"Zootal" wrote in message
. 97.131...
mike wrote in
:

On Feb 10, 4:14 pm, Zootal wrote:
Here is a somewhat more esoteric question. I have to snake around
some stuff, and I can do it with two 90 degree elbows, or two "45"
degree elbows. In the end, will using the 45 elbows give noticably
increased wat
er
flow? The pipe goes into a shower valve that is 1/2 inch, and the
interio
r
of the valve is even more restricted, so I'm thinking in this case it
won
't
make any difference.

But out there in the real world where we bend this way and that way,
does it matter how sharp the bend is wrt water volume?

Don't worry about it.

But I can tell you're an obsessive type, so if you want, you can look
up the equivalent friction loss of a 90 degree and 45 degree elbow
with regard to pipe diameters in a fluid dynamics book at the library
or on Google books if you don't believe me. From what I recall,
neither is significant, and you won't notice a difference.

Worry about low-flow shower heads instead.

I am cursed with curiosity for just about everything... ggg what if...?
what if ... ? what if ... ?

Proly not the biggest deal, but certainly two 45s are more elegant.
Slightly more expensive than one 90, but certainly more correct.
And the effect of pressure loss will be proportional to flow -- truly
insignificant with a low-flo shower head, perhaps noticeable in something
like a high-flo garden hose..
90s in air conditioning have a pretty substantial effect, and 45s would be a
good idea there.
--
EA

Zootal wrote:

Here is a somewhat more esoteric question. I have to snake around some
stuff, and I can do it with two 90 degree elbows, or two "45" degree
elbows. In the end, will using the 45 elbows give noticably increased water
flow? The pipe goes into a shower valve that is 1/2 inch, and the interior
of the valve is even more restricted, so I'm thinking in this case it won't
make any difference.

But out there in the real world where we bend this way and that way, does
it matter how sharp the bend is wrt water volume?

The more bend, the more velocity loss which is perceived as low pressure
when a faucet is open. It is beneficial to minimize the amount of bends
in a run of pipe. If a large number can not be avoided, stepping up to
the next larger pipe size will help compensate for the restrictions.

Zootal wrote:

I am cursed with curiosity for just about everything... ggg what
if...? what if ... ? what if ... ?

Talk about self-referential...

Have you ever wondered why you wonder about so much? It could take a
lifetime to discover that answer.

"Pete C." wrote in message
ter.com...

Zootal wrote:

Here is a somewhat more esoteric question. I have to snake around some
stuff, and I can do it with two 90 degree elbows, or two "45" degree
elbows. In the end, will using the 45 elbows give noticably increased
water
flow? The pipe goes into a shower valve that is 1/2 inch, and the
interior
of the valve is even more restricted, so I'm thinking in this case it
won't
make any difference.

But out there in the real world where we bend this way and that way, does
it matter how sharp the bend is wrt water volume?

The more bend, the more velocity loss which is perceived as low pressure
when a faucet is open. It is beneficial to minimize the amount of bends
in a run of pipe. If a large number can not be avoided, stepping up to
the next larger pipe size will help compensate for the restrictions.

I just built a shower with 1/2" copper. It feeds 3 shower heads. If I had to
do it again, I would feed it with 3/4" to the valve. It is OK but the
pressure could be better. If you turn off one of them, the other two are
better. My shower valve is a 1/2" feed too with a small opening inside the
valve. I thought that using the bathtub feed which is larger would
compensate as it is larger than the shower outlet in the top of the valve,
but it is still lacking on volume and pressure.

R



--- news://freenews.netfront.net/ - complaints: ---

On Feb 10, 6:14*pm, Zootal wrote:
Here is a somewhat more esoteric question. I have to snake around some
stuff, and I can do it with two 90 degree elbows, or two "45" degree
elbows. In the end, will using the 45 elbows give noticably increased water
flow? The pipe goes into a shower valve that is 1/2 inch, and the interior
of the valve is even more restricted, so I'm thinking in this case it won't
make any difference.

But out there in the real world where we bend this way and that way, does
it matter how sharp the bend is wrt water volume?

Common sense would be that two 45s are better than two 90s. But if
they area only to feed a shower head, I don't think even the pickiest
person would be able to tell the difference.

Zootal wrote:
wrote in
:

On Feb 10, 4:14 pm, wrote:
Here is a somewhat more esoteric question. I have to snake around
some stuff, and I can do it with two 90 degree elbows, or two "45"
degree elbows. In the end, will using the 45 elbows give noticably
increased wat
er
flow? The pipe goes into a shower valve that is 1/2 inch, and the
interio
r
of the valve is even more restricted, so I'm thinking in this case it
won
't
make any difference.

But out there in the real world where we bend this way and that way,
does it matter how sharp the bend is wrt water volume?

Don't worry about it.

But I can tell you're an obsessive type, so if you want, you can look
up the equivalent friction loss of a 90 degree and 45 degree elbow
with regard to pipe diameters in a fluid dynamics book at the library
or on Google books if you don't believe me. From what I recall,
neither is significant, and you won't notice a difference.

Worry about low-flow shower heads instead.

I am cursed with curiosity for just about everything...ggg what if...?
what if ... ? what if ... ?
Hi,
To me I wouldn't worry about it. Do you sleep good in the night?

I am cursed with curiosity for just about everything...ggg what
if...? what if ... ? what if ... ?
Hi,
To me I wouldn't worry about it. Do you sleep good in the night?


Like a baby :-)

Better than a baby - my kids always woke up at all odd hours of the night.
Maybe like a log would be a better analogy.

Zootal wrote:
I am cursed with curiosity for just about everything...ggg what
if...? what if ... ? what if ... ?
Hi,
To me I wouldn't worry about it. Do you sleep good in the night?


Like a baby :-)

Better than a baby - my kids always woke up at all odd hours of the night.
Maybe like a log would be a better analogy.
Hi,
Oh, man, you're blessed. One of 3 important health indicator.
The other two are eating well and eliminating well.

Tony Hwang wrote in
:

Zootal wrote:
I am cursed with curiosity for just about everything...ggg what
if...? what if ... ? what if ... ?
Hi,
To me I wouldn't worry about it. Do you sleep good in the night?


Like a baby :-)

Better than a baby - my kids always woke up at all odd hours of the
night. Maybe like a log would be a better analogy.
Hi,
Oh, man, you're blessed. One of 3 important health indicator.
The other two are eating well and eliminating well.


I was pretty busy tonight, so I didn't get a chance for dinner until late.
I had a bowel of cottage cheese, and another bowl with kimchi, kimchi
radish, and a few slices of some summer sausage left over from Christmas. I
can hear the EEEWWWs already....

I'll decline to comment on the third health indicator :-)

On Feb 10, 5:03*pm, Zootal wrote:
mike wrote :





On Feb 10, 4:14*pm, Zootal wrote:
Here is a somewhat more esoteric question. I have to snake around
some stuff, and I can do it with two 90 degree elbows, or two "45"
degree elbows. In the end, will using the 45 elbows give noticably
increased wat
er
flow? The pipe goes into a shower valve that is 1/2 inch, and the
interio
r
of the valve is even more restricted, so I'm thinking in this case it
won
't
make any difference.

But out there in the real world where we bend this way and that way,
does it matter how sharp the bend is wrt water volume?

Don't worry about it.

But I can tell you're an obsessive type, so if you want, you can look
up the equivalent friction loss of a 90 degree and 45 degree elbow
with regard to pipe diameters in a fluid dynamics book at the library
or on Google books if you don't believe me. *From what I recall,
neither is significant, and you won't notice a difference.

Worry about low-flow shower heads instead.

I am cursed with curiosity for just about everything... ggg what if...?
what if ... ? what if ... ?- Hide quoted text -

- Show quoted text -

Per mike's research, it appears that 2 45 are so close to identical to
1 90 that....

In any case, the additional 'drag' on your flow will be so small as to
not be noticeable unless system pressure is so low as to be considered
a failure anyhow.

Harry K

On Feb 10, 9:36*pm, Zootal wrote:
Tony Hwang wrote :

Zootal wrote:
I am cursed with curiosity for just about everything...ggg * what
if...? what if ... ? what if ... ?
Hi,
To me I wouldn't worry about it. Do you sleep good in the night?

Like a baby :-)

Better than a baby - my kids always woke up at all odd hours of the
night. Maybe like a log would be a better analogy.
Hi,
Oh, man, you're blessed. One of 3 important health indicator.
The other two are eating well and eliminating well.

I was pretty busy tonight, so I didn't get a chance for dinner until late..
I had a bowel of cottage cheese, and another bowl with kimchi, kimchi
radish, and a few slices of some summer sausage left over from Christmas. I
can hear the EEEWWWs already....

I'll decline to comment on the third health indicator :-)

I feel for anyone sleeping with you

Harry K

Zootal wrote:
I am cursed with curiosity for just about everything...ggg what
if...? what if ... ? what if ... ?
Hi,
To me I wouldn't worry about it. Do you sleep good in the night?


Like a baby :-)

Better than a baby - my kids always woke up at all odd hours of the night.
Maybe like a log would be a better analogy.

I once told this gal that she wouldn't want to sleep with me.
She asked why not, I answered, because I sleep like a baby, I
wake up crying every two hours and want to nurse.

TDD

Zootal wrote:
Tony Hwang wrote in
:

Zootal wrote:
I am cursed with curiosity for just about everything...ggg what
if...? what if ... ? what if ... ?
Hi,
To me I wouldn't worry about it. Do you sleep good in the night?

Like a baby :-)

Better than a baby - my kids always woke up at all odd hours of the
night. Maybe like a log would be a better analogy.
Hi,
Oh, man, you're blessed. One of 3 important health indicator.
The other two are eating well and eliminating well.


I was pretty busy tonight, so I didn't get a chance for dinner until late.
I had a bowel of cottage cheese, and another bowl with kimchi, kimchi
radish, and a few slices of some summer sausage left over from Christmas. I
can hear the EEEWWWs already....

I'll decline to comment on the third health indicator :-)

Capture the result, it's a good form of alternative energy.

TDD

On Feb 10, 7:35*pm, "Stormin Mormon"
wrote:
I studied this about 25 years ago, when I was taking some
fire protection courses. The 45 are far less restrictive.



They quote the flow restriction of the various fittings by the amount
of equivalent pipe length they add. And while the 45s are
individually about 5x less restrictive, you do need to then use two of
them and the net effect in the given application isn't enough to make
any noticeable difference. For example, a 1/2" 90deg elbow is
equivalent to 3.6 feet of pipe. A 1/2" long radius 90 is equiv to
2.2 feet. A regular 45 elbow is .7 feet.

So, using two 45's, you get 1.4 feet versus 3.6 feet, saving
equivalent to 2.2 feet of additional pipe run. If you used a long
radius 90 elbow, you'd only be saving .8 feet of equiv pipe.

Those numbers were for screwed fittings, but similar effects are going
to apply to copper as well.

http://www.engineeringtoolbox.com/re...gth-d_192.html

"Existential Angst" wrote in message
...
"Zootal" wrote in message
. 97.131...
mike wrote in
:

On Feb 10, 4:14 pm, Zootal wrote:
Here is a somewhat more esoteric question. I have to snake around
some stuff, and I can do it with two 90 degree elbows, or two "45"
degree elbows. In the end, will using the 45 elbows give noticably
increased wat
er
flow? The pipe goes into a shower valve that is 1/2 inch, and the
interio
r
of the valve is even more restricted, so I'm thinking in this case it
won
't
make any difference.

But out there in the real world where we bend this way and that way,
does it matter how sharp the bend is wrt water volume?

Don't worry about it.

But I can tell you're an obsessive type, so if you want, you can look
up the equivalent friction loss of a 90 degree and 45 degree elbow
with regard to pipe diameters in a fluid dynamics book at the library
or on Google books if you don't believe me. From what I recall,
neither is significant, and you won't notice a difference.

Worry about low-flow shower heads instead.

I am cursed with curiosity for just about everything... ggg what if...?
what if ... ? what if ... ?

Proly not the biggest deal, but certainly two 45s are more elegant.
Slightly more expensive than one 90, but certainly more correct.
And the effect of pressure loss will be proportional to flow -- truly
insignificant with a low-flo shower head, perhaps noticeable in something
like a high-flo garden hose..
90s in air conditioning have a pretty substantial effect, and 45s would be
a good idea there.
--
EA


Personally, I always use a 45 degree elbow when I have a choice. For example
to change directions and elevations at the same location, such as when a
pipe is traveling parallel to and between joists and must make a 90 degree
turn and drop below the joists, I always use the 45 to angle down to below
the joist and then a 90 to turn across the bottom of the joist. If I am
going around something such as another pipe where one would need 4 90s to
get around the obstruction, I always use 4 45s to accomplish it, if the
obstruction is only slight, I will try to use "street" 45s to accomplish the
offset. To me it looks better, it does improve the water low and also
reduces noise at a high water flow.

"EXT" wrote in
anews.com:


"Existential Angst" wrote in message
...
"Zootal" wrote in message
. 97.131...
mike wrote in

:

On Feb 10, 4:14 pm, Zootal wrote:
Here is a somewhat more esoteric question. I have to snake around
some stuff, and I can do it with two 90 degree elbows, or two "45"
degree elbows. In the end, will using the 45 elbows give noticably
increased wat
er
flow? The pipe goes into a shower valve that is 1/2 inch, and the
interio
r
of the valve is even more restricted, so I'm thinking in this case
it won
't
make any difference.

But out there in the real world where we bend this way and that
way, does it matter how sharp the bend is wrt water volume?

Don't worry about it.

But I can tell you're an obsessive type, so if you want, you can
look up the equivalent friction loss of a 90 degree and 45 degree
elbow with regard to pipe diameters in a fluid dynamics book at the
library or on Google books if you don't believe me. From what I
recall, neither is significant, and you won't notice a difference.

Worry about low-flow shower heads instead.

I am cursed with curiosity for just about everything... ggg what
if...? what if ... ? what if ... ?

Proly not the biggest deal, but certainly two 45s are more elegant.
Slightly more expensive than one 90, but certainly more correct.
And the effect of pressure loss will be proportional to flow -- truly
insignificant with a low-flo shower head, perhaps noticeable in
something like a high-flo garden hose..
90s in air conditioning have a pretty substantial effect, and 45s
would be a good idea there.
--
EA


Personally, I always use a 45 degree elbow when I have a choice. For
example to change directions and elevations at the same location, such
as when a pipe is traveling parallel to and between joists and must
make a 90 degree turn and drop below the joists, I always use the 45
to angle down to below the joist and then a 90 to turn across the
bottom of the joist. If I am going around something such as another
pipe where one would need 4 90s to get around the obstruction, I
always use 4 45s to accomplish it, if the obstruction is only slight,
I will try to use "street" 45s to accomplish the offset. To me it
looks better, it does improve the water low and also reduces noise at
a high water flow.



Ah, there is something I hadn't thought of. How much more likely are the
pipes to hammer because of 90 degree elbows, versus 45? I would bet that
45's are quite unlikely to cause hammering problems. though two 45's in a
row might hammer just the same as a 90. Just guessing - I'm way outside
of my area of expertise here. I don't want to do plumbing long enough to
actually get good at it :-P

On Feb 11, 8:20*am, wrote:
On Feb 10, 7:35*pm, "Stormin Mormon"

wrote:
I studied this about 25 years ago, when I was taking some
fire protection courses. The 45 are far less restrictive.

They quote the flow restriction of the various fittings by the amount
of equivalent pipe length they add. * And while the 45s are
individually about 5x less restrictive, you do need to then use two of
them and the net effect in the given application isn't enough to make
any noticeable difference. * * For example, a 1/2" *90deg elbow is
equivalent to 3.6 feet of pipe. * A 1/2" long radius 90 is equiv to
2.2 feet. * A regular 45 elbow is .7 feet.

So, using two 45's, you get 1.4 feet versus 3.6 feet, saving
equivalent to 2.2 feet of additional pipe run. * *If you used a long
radius 90 elbow, you'd only be saving .8 feet of equiv pipe.

Those numbers were for screwed fittings, but similar effects are going
to apply to copper as well.

http://www.engineeringtoolbox.com/re...t-length-d_192....

But the OP said 2-90's or two 45's

On Wed, 10 Feb 2010 18:14:08 -0600, Zootal
wrote:

Here is a somewhat more esoteric question. I have to snake around some
stuff, and I can do it with two 90 degree elbows, or two "45" degree
elbows. In the end, will using the 45 elbows give noticably increased water
flow? The pipe goes into a shower valve that is 1/2 inch, and the interior
of the valve is even more restricted, so I'm thinking in this case it won't
make any difference.

But out there in the real world where we bend this way and that way, does
it matter how sharp the bend is wrt water volume?


There are several factors that help or hinder water flow. The area
of study is called "fluidics" and often taught in mechanical
engineering courses. For home plumbing, it probably doesn't matter if
you use 45 or 90 degree elbows. I prefer the 90-degree bend and only
use the 45-degree elbow if required.

Long radius 90 have less resistance, though I'm
not sure if they are made.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Phisherman" wrote in message
...
On Wed, 10 Feb 2010 18:14:08 -0600, Zootal
wrote:

Here is a somewhat more esoteric question. I have
to snake around some
stuff, and I can do it with two 90 degree elbows,
or two "45" degree
elbows. In the end, will using the 45 elbows give
noticably increased water
flow? The pipe goes into a shower valve that is
1/2 inch, and the interior
of the valve is even more restricted, so I'm
thinking in this case it won't
make any difference.

But out there in the real world where we bend
this way and that way, does
it matter how sharp the bend is wrt water volume?


There are several factors that help or hinder
water flow. The area
of study is called "fluidics" and often taught in
mechanical
engineering courses. For home plumbing, it
probably doesn't matter if
you use 45 or 90 degree elbows. I prefer the
90-degree bend and only
use the 45-degree elbow if required.

On Feb 11, 12:48*pm, "hr(bob) "
wrote:
On Feb 11, 8:20*am, wrote:





On Feb 10, 7:35*pm, "Stormin Mormon"

wrote:
I studied this about 25 years ago, when I was taking some
fire protection courses. The 45 are far less restrictive.

They quote the flow restriction of the various fittings by the amount
of equivalent pipe length they add. * And while the 45s are
individually about 5x less restrictive, you do need to then use two of
them and the net effect in the given application isn't enough to make
any noticeable difference. * * For example, a 1/2" *90deg elbow is
equivalent to 3.6 feet of pipe. * A 1/2" long radius 90 is equiv to
2.2 feet. * A regular 45 elbow is .7 feet.

So, using two 45's, you get 1.4 feet versus 3.6 feet, saving
equivalent to 2.2 feet of additional pipe run. * *If you used a long
radius 90 elbow, you'd only be saving .8 feet of equiv pipe.

Those numbers were for screwed fittings, but similar effects are going
to apply to copper as well.

http://www.engineeringtoolbox.com/re...t-length-d_192....

But the OP said 2-90's or two 45's- Hide quoted text -

- Show quoted text -

Yes, I missed that he was considering two 90's, because in many cases
you would use one 90 or two 45s to achieve the same direction
change. So re-doing the math, he's save about 6 ft equivalent of
pipe. Which means all other things being equal, I'd use the two 45's.

On Feb 10, 7:35*pm, "Stormin Mormon"
wrote:
I studied this about 25 years ago, when I was taking some
fire protection courses. The 45 are far less restrictive.

--
Christopher A. Young
Learn more about Jesus
*www.lds.org
.

"Zootal" wrote in message

. 97.131...
Here is a somewhat more esoteric question. I have to snake
around some
stuff, and I can do it with two 90 degree elbows, or two
"45" degree
elbows. In the end, will using the 45 elbows give noticably
increased water
flow? The pipe goes into a shower valve that is 1/2 inch,
and the interior
of the valve is even more restricted, so I'm thinking in
this case it won't
make any difference.

But out there in the real world where we bend this way and
that way, does
it matter how sharp the bend is wrt water volume?

If 45's are less restrictive than 90's, then the smooth curves of Pex
must be even better.

On Feb 11, 5:31*pm, "Stormin Mormon"
wrote:
Long radius 90 have less resistance, though I'm
not sure if they are made.

--
Christopher A. Young
Learn more about Jesus
*www.lds.org
.

"Phisherman" wrote in message

...
On Wed, 10 Feb 2010 18:14:08 -0600, Zootal



wrote:
Here is a somewhat more esoteric question. I have
to snake around some
stuff, and I can do it with two 90 degree elbows,
or two "45" degree
elbows. In the end, will using the 45 elbows give
noticably increased water
flow? The pipe goes into a shower valve that is
1/2 inch, and the interior
of the valve is even more restricted, so I'm
thinking in this case it won't
make any difference.

But out there in the real world where we bend
this way and that way, does
it matter how sharp the bend is wrt water volume?

There are several factors that help or hinder
water flow. * The area
of study is called "fluidics" and often taught in
mechanical
engineering courses. *For home plumbing, it
probably doesn't matter if
you use 45 or 90 degree elbows. * I prefer the
90-degree bend and only
use the 45-degree elbow if required.

SM-

They are still made (long sweep copper tube elbows) & are available
(at a minimum) at McMaster.

When I wonder if something is "available", I use McMaster as an
"existence check".
If McMaster has it, it's got to be available elsewhere as well,
probably for less.
If I'm in a hurry or dont want to research another source, I buy it
from McMaster.

Pay with a CC and purchase before noon, I can have it before end of
business that day or early the next day.


I used to say......... "if it ain't in the McMaster catalog, it
probably doesn't exist and you probably don't need it anyway."

cheers
Bob

Thank you for your kind wisdom. Isn't that like
Ralphs Pretty Good Grocery. I heard that on Prarie
Home Companion, years ago. I seldom listen to NPR
(National Liberal Radio). But it was on, the one
time I was visiting my Dad.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"DD_BobK" wrote in message
...

SM-

They are still made (long sweep copper tube
elbows) & are available
(at a minimum) at McMaster.

When I wonder if something is "available", I use
McMaster as an
"existence check".
If McMaster has it, it's got to be available
elsewhere as well,
probably for less.
If I'm in a hurry or dont want to research another
source, I buy it
from McMaster.

Pay with a CC and purchase before noon, I can have
it before end of
business that day or early the next day.


I used to say......... "if it ain't in the
McMaster catalog, it
probably doesn't exist and you probably don't need
it anyway."

cheers
Bob

In article , "Stormin Mormon" wrote:
Thank you for your kind wisdom. Isn't that like
Ralphs Pretty Good Grocery. I heard that on Prarie
Home Companion, years ago. I seldom listen to NPR
(National Liberal Radio). But it was on, the one
time I was visiting my Dad.

When are you going to fix your newsreader configuration so it puts your sig at
the bottom where it belongs?

In . 97.131,
Zootal typed:
"EXT" wrote in
anews.com:


"Existential Angst" wrote in message
...
"Zootal" wrote in message
. 97.131...
mike wrote in



On Feb 10, 4:14 pm, Zootal wrote:
Here is a somewhat more esoteric question. I have to snake around
some stuff, and I can do it with two 90 degree elbows, or two
"45" degree elbows. In the end, will using the 45 elbows give
noticably increased wat
er
flow? The pipe goes into a shower valve that is 1/2 inch, and the
interio
r
of the valve is even more restricted, so I'm thinking in this
case it won
't
make any difference.

But out there in the real world where we bend this way and that
way, does it matter how sharp the bend is wrt water volume?

Don't worry about it.

But I can tell you're an obsessive type, so if you want, you can
look up the equivalent friction loss of a 90 degree and 45 degree
elbow with regard to pipe diameters in a fluid dynamics book at
the library or on Google books if you don't believe me. From
what I recall, neither is significant, and you won't notice a
difference.

Worry about low-flow shower heads instead.

I am cursed with curiosity for just about everything... ggg what
if...? what if ... ? what if ... ?

Proly not the biggest deal, but certainly two 45s are more elegant.
Slightly more expensive than one 90, but certainly more correct.
And the effect of pressure loss will be proportional to flow --
truly insignificant with a low-flo shower head, perhaps noticeable
in something like a high-flo garden hose..
90s in air conditioning have a pretty substantial effect, and 45s
would be a good idea there.
--
EA


Personally, I always use a 45 degree elbow when I have a choice. For
example to change directions and elevations at the same location,
such as when a pipe is traveling parallel to and between joists and
must make a 90 degree turn and drop below the joists, I always use
the 45 to angle down to below the joist and then a 90 to turn across
the bottom of the joist. If I am going around something such as
another pipe where one would need 4 90s to get around the
obstruction, I always use 4 45s to accomplish it, if the obstruction
is only slight, I will try to use "street" 45s to accomplish the
offset. To me it looks better, it does improve the water low and
also reduces noise at a high water flow.



Ah, there is something I hadn't thought of. How much more likely are
the pipes to hammer because of 90 degree elbows, versus 45? I would
bet that 45's are quite unlikely to cause hammering problems. though
two 45's in a row might hammer just the same as a 90. Just guessing -
I'm way outside of my area of expertise here. I don't want to do
plumbing long enough to actually get good at it :-P

Not likely to make any difference, I don't think. Hammering is more the
effect of quickly turning a faucet off quickly which lets the water's
inertia try to move the whole pipe system and thus "hammers". If anything,
90 would improve it by adding some damping or slowing to the "hammer"
action.

HTH,

Twayne



--
--
Newsgroups are great places to get assistance.
But always verify important information with
other sources to be certain you have a clear
understanding of it and that it is accurate.

In . 97.131,
Zootal typed:
Here is a somewhat more esoteric question. I have to snake around some
stuff, and I can do it with two 90 degree elbows, or two "45" degree
elbows. In the end, will using the 45 elbows give noticably increased
water flow? The pipe goes into a shower valve that is 1/2 inch, and
the interior of the valve is even more restricted, so I'm thinking in
this case it won't make any difference.

But out there in the real world where we bend this way and that way,
does it matter how sharp the bend is wrt water volume?

As long as the end-of-the-line is short in distance and smaller in diameter
than the source up to that point, it's always going to be fine unless
something odd comes into play. And especially if you leave the lo-flow
restrictor in place - heck, you could probably feed that with 1/4" pipeG!
Personally, first thing I do with a shower is remove the restrictor
especially if it's one of the temperature-monitoring non-scald types, which
is about all you can buy today. I love that constant temp setting; let them
flush the toilet and run the washer; all I see is a difference in water
pressure but no temp changes of more than barely noticeable.

HTH,

Twayne



--
--
Newsgroups are great places to get assistance.
But always verify important information with
other sources to be certain you have a clear
understanding of it and that it is accurate.