# whats more important in plumbing, pressure or volume?



## abudgetplumb (Aug 22, 2011)

in my 2nd year of apprenticeship, our teacher asked us "whats more important in plumbing, pressure or volume?" what do you think.


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## nhmaster3015 (Aug 5, 2008)

I think you need a different teacher


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## user4 (Jun 12, 2008)

abudgetplumb said:


> in my 2nd year of apprenticeship, our teacher asked us "whats more important in plumbing, pressure or volume?" what do you think.


Vacuum.


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## Tommy plumber (Feb 19, 2010)

Depends on the situation and what you are trying to accomplish...:yes:


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## Airgap (Dec 18, 2008)

Pressure= chained to kitchen table....Less tiring, I vote yes.

Volume= Door to door canvassing....Too much walking, I vote no.


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## abudgetplumb (Aug 22, 2011)

that's how the Q was presented 2 us. overall, what's more important


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## Widdershins (Feb 5, 2011)

T&M, cordless, on the flange and putty.


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## Redwood (Sep 8, 2008)

Should have been a multiple choice poll with an it depends as the 3rd choice...


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## easttexasplumb (Oct 13, 2010)

I have heard as you get older your pressure gets lower.


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## user4 (Jun 12, 2008)

easttexasplumb said:


> I have heard as you get older your pressure gets lower.



And if you eat too much cheese you can't fart.


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## TX MECH PLUMBER (May 27, 2011)

The health and welfare of the public!! That's your most important responsibility ! Not enough pressure get a pump and tank. Not enough volume get tank and pump... Lol. Both are important. It's a trick question....


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## plbgbiz (Aug 27, 2010)

abp: *"Mr. Teacher, I believe I am close to the answer, but I have to ask you a question first"*

teacher:_ *"OK Mr. Student, let's hear it"*_

abp: *"Since high pressure water hits you harder and high volume water gets you wetter, to answer your question I first have to know if you want to be hit hard or if your just all wet."*


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## SewerRatz (Apr 25, 2009)

Just FYI Chicago has a high volume low pressure system.


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## Tommy plumber (Feb 19, 2010)

abudgetplumb said:


> in my 2nd year of apprenticeship, our teacher asked us "whats more important in plumbing, pressure or volume?" what do you think.


 




Tell the teacher if he's trying to wash a big turd down a vertical stack, then pressure isn't needed...only volume...:laughing:

And if he wants water on the 100th floor of the World Trade Center, then pressure is what he needs...and not much volume...:yes:


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## U666A (Dec 11, 2010)

There should be an answer that says "I just hate green circles! "


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## abudgetplumb (Aug 22, 2011)

our teacher told us, volume was(overall) because if you have volume you can have pressure but good pressure does not ensure good volume


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## Redwood (Sep 8, 2008)

abudgetplumb said:


> our teacher told us, volume was(overall) because if you have volume you can have pressure but good pressure does not ensure good volume


Plenty of volume sitting in the reservoir...

But if there isn't enough pressure to push it up the hill to your home you will never see volume....:whistling2:


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## rocksteady (Oct 8, 2008)

It's like asking "what's more important, current or voltage?" You need both, one without the other is useless in a practical real world plumbing system. Having an olympic sized swimming pool in your back yard won't get water to flow out of your shower head.





Paul


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## BROOKLYN\PLUMB (May 21, 2010)

abudgetplumb said:


> in my 2nd year of apprenticeship, our teacher asked us "whats more important in plumbing, pressure or volume?" what do you think.


I really thought you were talking sales 
I think your teacher is an idiot that is the stupidest question ever why don't you ask him which is more important in combustion fuel or oxygen


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## SewerRatz (Apr 25, 2009)

I still say volume of water is more imprtant since you can use booter pumps in the building to get pressure. I always wonder how they get any pressure in the Highrises in Chicago. Wish one day I could have a look at how its all plumbed. Most of Chicago you will see 35 PSI.


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## nhmaster3015 (Aug 5, 2008)

some people say that there is no such thing as a dumb question. they would be wrong. There are plenty of dumb questions. This is one of them.


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## Associated Plum (Nov 4, 2008)

Single story residence, galvanized house piping on water, rusted up on the inside, static pressure @ house 65psi.

Turn on lavatory faucet everything looks great, but open another faucet and hardly any water comes out. The pressure is still the same, yet there is not enough volumne to feed both faucets.

2.5 showerheads work fine, but take out the restrictor and they work better. Why because of more volumne not pressure.

Client call al the time and tell us they do not have enough pressure, when it is actually a volumne problem


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## plumb nutz (Jan 28, 2011)

Do like the question nor the poll... Pressure is needed to move the volume, volume is needed to supply the fixtures, hence required supply requirements with minimum working pressure... 
The two go hand in hand...


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## njoy plumbing (May 19, 2009)

At 51, I will vote pressure. It takes forever to have a piss.


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## PLUMBER_BILL (Oct 23, 2009)

njoy plumbing said:


> At 51, I will vote pressure. It takes forever to have a piss.


I voted pressure. All work is designed on pressure. Correct pipe sizing giveg you volume. Try to flush a sloan 1'' piping @ 2 psi.

Did it work?


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## cityplumbing (Jun 12, 2010)

I think in a plumbing system you need both pressure and volume and I think there both equally important.


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## nhmaster3015 (Aug 5, 2008)

You're thinking too much :laughing:


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## U666A (Dec 11, 2010)

nhmaster3015 said:


> You're thinking too much :laughing:


I agree... I've gone cross-eyed!

:laughing:


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## stillaround (Mar 11, 2009)

SewerRatz said:


> I still say volume of water is more imprtant since you can use booter pumps in the building to get pressure. I always wonder how they get any pressure in the Highrises in Chicago. Wish one day I could have a look at how its all plumbed. Most of Chicago you will see 35 PSI.


I serviced lake shore drive for several years...for 25-35 story they pumped the water up to the top floor and starting with 2" each tier then reduce the size of the riser every several floors till the ground floor where a 3/4" return on the hot was. So they pumped up in a large volume pipe and let gravity help on the drops...each 5 floors had a swing joint made of 4 elbows and it was galvanized pipe...pressure at the laundry rooms on the ground or basement was around 125. It was called a downfeed system.
The swing joints used to rust closed and the temp of the hot was the tepid return temp and we knew to go to the next swing joint up from the problem floor and replace it.

Also Chicago required 1/2 od supplies and not 3/8ths...dont know if its still true.


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## ToUtahNow (Jul 19, 2008)

abudgetplumb said:


> that's how the Q was presented 2 us. overall, what's more important


There is really not a correct answer. If you have high volume but low pressure you need a storage tank and pump. If you have high pressure and low volume you need a storage tank and pump. I guess the correct answer might be which ever one you don't currently have.

Mark


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## ToUtahNow (Jul 19, 2008)

PLUMBER_BILL said:


> I voted pressure. All work is designed on pressure. Correct pipe sizing giveg you volume. Try to flush a sloan 1'' piping @ 2 psi.
> 
> Did it work?


Try flushing the same sloan valve with 40 psi @ .25 gpm.

Mark


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## grandpa (Jul 13, 2008)

PLUMBER_BILL said:


> I voted pressure. All work is designed on pressure. Correct pipe sizing giveg you volume. Try to flush a sloan 1'' piping @ 2 psi.
> 
> Did it work?


 
Bill has hinted at the correct answer here...which is that you cannot operate in a vacuum...using only one factor and completely ignoring the other. All the pressure in the world is not a good solution if the system cannot deliver volume...and huge volume is not help if you start with no pressure.

You could make a point that you could start with 500 psi, and pipe a house with 1/4" copper, and still get enough water to brush your teeth or fill a toilet. I say.... git'r done. Let us know how you like it.


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## AlbacoreShuffle (Aug 28, 2011)

easttexasplumb said:


> I have heard as you get older your pressure gets lower.


Thats true, and if your old enough , you can laugh, pee, sneeze and fart at the same time !


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## Widdershins (Feb 5, 2011)

AlbacoreShuffle said:


> Thats true, and if your old enough , you can laugh, pee, sneeze and fart at the same time !


 Just make sure you don't use the same tissue to blow your nose.


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## DUNBAR PLUMBING (Sep 11, 2008)

*No pressure, no volume... not in this galvanized piping*


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## Don The Plumber (Feb 14, 2010)

DUNBAR PLUMBING said:


> How to Remove a Galvanized Nipple in your Water Line - YouTube


 
Looks like you need to test those sales skills of yours, & sell them a repipe.:yes: They probably think this is the only rusty pipe in the plumbing system.:laughing:


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## swedishcharm21 (Oct 29, 2011)

You need BOTH. Neither is more or less important than the other. There are codes for both of these key ingredients. Pressure boosting and pressure reducing valves can correct a lot of issues and put you within limits. Correct pipe sizing helps a lot of things too. Obviously you would do your runs in 3/4 most likely and stub up to the fixture with 1/2. Usually your last 2 fixtures are with 3/4x1/2x1x2 tee. Also pre-existing systems that suffer these discrepancies can be caused from many issues Ie; Debris in supply line, clogged aerators, rusty crustys from galvanized causing obstruction, poor pressure form the city, poor quality fixtures....etc.

Either way, they are BOTH important. There are many ways to correct poor volume or pressure.


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## SimplePlumber (Feb 1, 2012)

abudgetplumb said:


> in my 2nd year of apprenticeship, our teacher asked us "whats more important in plumbing, pressure or volume?" what do you think.


I would guess it was presented to be a trick question. If it wasn't, it was poorly thought out or the context in which it was asked is missing.

My answer; neither.


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## Miguel (Aug 10, 2009)

Cheeze you guys. You all missed it! Payday is today... oh crap, it's NEXT Friday. Okay then, the next important thing is it all goes down hill.

Next question.


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## OldSchool (Jan 30, 2010)

SimplePlumber said:


> I would guess it was presented to be a trick question. If it wasn't, it was poorly thought out or the context in which it was asked is missing.
> 
> My answer; neither.


My answer is both because with out one or the other you got nothing

Sent from my portable office....yes I am at work


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## Miguel (Aug 10, 2009)

Okay I'm gonna double post once again but only because the poor lad is completely surrounded by master plumbers yet getting vague hints at best. Well the correct answer has been thrown out there more'n once but still only clear as mud.

Check this:
You have a toilet bowl with a trap full of water containing 1.34 litres of water as a trap seal only. It is a modern reverse trap siphon jet.
Connected to it is an 850 USG tank filled with water to a level equal to the height of the water in the bowl.

Next to it you have an identical toilet bowl containing the same amount of water. Connected to it is a vertical pipe rising to 642' and a tank containing no water. (The toilet bowls in both cases are 323 meters above sea level.

Which bowl will flushe the best?


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## Miguel (Aug 10, 2009)

OldSchool said:


> My answer is both because with out one or the other you got nothing
> 
> Sent from my portable office....yes I am at work


Waddayouknow? You've been drinking.


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## OldSchool (Jan 30, 2010)

Miguel said:


> Waddayouknow? You've been drinking.


What else am I suppose to do on a Friday night ... Other than have a few then go to some old lady house to help her out

Sent from my portable office....yes I am at work


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## OldSchool (Jan 30, 2010)

Miguel said:


> Okay I'm gonna double post once again but only because the poor lad is completely surrounded by master plumbers yet getting vague hints at best. Well the correct answer has been thrown out there more'n once but still only clear as mud.
> 
> Check this:
> You have a toilet bowl with a trap full of water containing 1.34 litres of water as a trap seal only. It is a modern reverse trap siphon jet.
> ...


I don't get it we are 2,000 ft above sea level

So who has been drinking?

Sent from my portable office....yes I am at work


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## Miguel (Aug 10, 2009)

:laughing:

Happy Friday, my brother.


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## OldSchool (Jan 30, 2010)

So lets put it this way

Seeing I am 2,000 ft above sea level

And I was providing water to Florida

And my water pressure was at 15 psi ... What would be the water pressure I was supplying to Florida?

Sent from my portable office....yes I am at work


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## Mississippiplum (Sep 30, 2011)

OldSchool said:


> So lets put it this way
> 
> Seeing I am 2,000 ft above sea level
> 
> ...


I'm at 12 ft above sea lvl here in fl 

Idk but that's ALOT of pressure.

sent from the jobsite porta-potty


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## OldSchool (Jan 30, 2010)

Mississippiplum said:


> I'm at 12 ft above sea lvl here in fl
> 
> Idk but that's ALOT of pressure.
> 
> sent from the jobsite porta-potty


Would it be?

There is variables

Sent from my portable office....yes I am at work


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## Miguel (Aug 10, 2009)

Mississippiplum said:


> I'm at 12 ft above sea lvl here in fl
> 
> Idk but that's ALOT of pressure.
> 
> sent from the jobsite porta-potty


3/4" PEX Sharbite'd together every 20' should give you enough friction loss to turn on a tap.


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## OldSchool (Jan 30, 2010)

Miguel said:


> 3/4" PEX Sharbite'd together every 20' should give you enough friction loss to turn on a tap.


That's about what I figured

Sent from my portable office....yes I am at work


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## DUNBAR PLUMBING (Sep 11, 2008)

Don The Plumber said:


> Looks like you need to test those sales skills of yours, & sell them a repipe.:yes: They probably think this is the only rusty pipe in the plumbing system.:laughing:


 

10 grand, they already know I'll be starting at the floor of the basement to the rooftop.


They're waiting for an income tax check and I'm in the till.


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## Don The Plumber (Feb 14, 2010)

DUNBAR PLUMBING said:


> 10 grand, they already know I'll be starting at the floor of the basement to the rooftop.
> 
> 
> They're waiting for an income tax check and I'm in the till.


 
10 grand?:confused1:

What are you using, pex?:laughing:

These people still have a wash basin, with seperate hot & cold bib faucets, from 1940, & now they're going to all of a sudden, come up with, & spend, 10 K? I am betting that when they get that tax return check in hand, those plumbing pipes are gonna seem pretty boring, to spend all that money on.

I'll believe it when your done, & paid in full.:yes: Let us know. You probably gotta open up some walls, ceilings, &/or floors, if this is multi story? So they got lots of expenses too, after your done. Good luck!


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## SimplePlumber (Feb 1, 2012)

OldSchool said:


> My answer is both because with out one or the other you got nothing
> 
> Sent from my portable office....yes I am at work


The question was... whats *more* important in plumbing, pressure *or* volume?

We answered the same question two different ways but still saying the same thing.

Neither are *more* important...as in, they are equally important. :thumbsup:


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## Good Enuff P&H (Mar 24, 2012)

*Yikes !!*



DUNBAR PLUMBING said:


> How to Remove a Galvanized Nipple in your Water Line - YouTube


So are you done there or will you be re piping anything else?
Are the faucets wide open in the video?
At least if you need get to the tub valve you have that handy duct tape access panel.


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## CentralPlumbing (Jan 22, 2009)

abudgetplumb said:


> in my 2nd year of apprenticeship, our teacher asked us "whats more important in plumbing, pressure or volume?" what do you think.



Here is an interesting article you may find useful on water pressure vs volume.

http://www.keidel.com/resources/water/w-vol.htm


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