From my first response: "they (the water company) should be able to let you know if their existing supply line/meter can provide enough water for your new needs." Can't get much clearer than that, unless one cannot read and understand English.
Assistance with Commercial Toilet on 3/4" meter supply line.
- Thread starter BriarHouseBrew
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Folks, the only thing we'd like to do here is help out this member. I've had to edit and delete many unnecessary comments. Please let's keep this thread on track.
Yes, keep it on track. Don’t get distracted by people guessing and leading you down a dead end asking stupid questions to the wrong people.
And again for the record.
A 3/4” main into the building is not large enough for direct flush fixtures and to supply a building. It’s the bare minimum for a house and in some jurisdictions 1” is the minimum size for a home.
We’re talking about a commercial business.
No need to call anyone and ask stupid questions.i
Why is that so controversial on this thread ?
A 3/4” main into the building is not large enough for direct flush fixtures and to supply a building. It’s the bare minimum for a house and in some jurisdictions 1” is the minimum size for a home.
We’re talking about a commercial business.
No need to call anyone and ask stupid questions.i
Why is that so controversial on this thread ?
There’s no need to call the water company about that.
It simply Ain’t gunna werk bubba…..
In concept, this seems easy. In fact, I tried using the same philosophy with NG gas lines as a way to bypass the needed pressures, and my idea failed miserably. It is all about volume vs. pressure, and static pressure. There is alot of design and engineering behind volume and pressure.
The water company is not bound by plumbing code. They can flow 25 gallons a minute through 5/8 copper tubing at 120 psi. They can exceed the allowable flow velocity of the pipe. It doesn’t matter to anyone but them.
The customer is responsible for the piping on the outlet side of the meter and IS bound by plumbing code.
3/4” pipe is simply not large enough to supply a commercial building. It’s can supply roughly 12gpm and it’s flow velocity shouldn’t exceed approx. 8 fps. Or you’ll get erosion wear.
Pressure inside the building can’t exceed 80 psi.
The only 3/4” pipe that has been confirmed in this thread is the original posters main water service coming into the building. So that’s why I said it’s a waste of time to call the water company about THAT pipe.
It’s silly to even be discussing a 3/4” building main with direct flush valve toilets. When pigs fly……..
The customer is responsible for the piping on the outlet side of the meter and IS bound by plumbing code.
3/4” pipe is simply not large enough to supply a commercial building. It’s can supply roughly 12gpm and it’s flow velocity shouldn’t exceed approx. 8 fps. Or you’ll get erosion wear.
Pressure inside the building can’t exceed 80 psi.
The only 3/4” pipe that has been confirmed in this thread is the original posters main water service coming into the building. So that’s why I said it’s a waste of time to call the water company about THAT pipe.
It’s silly to even be discussing a 3/4” building main with direct flush valve toilets. When pigs fly……..
Hopefully a call to the water department, will allow the owner to be convinced that his pipe sizing is inadequate and recommend and offer advice on upgrading the system.
Volume and pressure have a relationship.
Static pressure is not a true reflection of how much volume of water is available.
You could have 80 psi static and open the tap and get a dribble after the initial pressure drop. Classic pipe restriction. Dynamic pressure 0
When you open a tap the relevant information is two fold. How many GPM are you getting and what dynamic pressure (flow condition pressure ) do you have. Flow velocity is also relevant but assuming the system was sized correctly initially, that won’t be a problem.
As the volume decreases under high load, the dynamic pressure takes a dump with it. So there’s your relationship.
When you flush one or several direct flush valve type fixtures at once the systems volume can be depleted and the dynamic flow pressure drops below the fixtures ability to close itself. The valves use water pressure to act upon a diaphragm via an orfice to close.
If not enough volume is supplied, the valve will stay in flush mode and run continuously until the pressure/volume increases to the minimum flow requirements of the valve.
In order to stop the fixture or fixtures from continuously running the dynamic pressure must be restored to above the minimum working pressure of the flush valve. The only way to do that is to manually turn the stop valves off to the fixtures so the system can build pressure.
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With natural gas you don’t have to worry about flow velocity in regards to pipe erosion but depending on where valves and fittings are placed in the system, the turbulence can affect pressure regulators and in turn cause some appliances to throw trouble codes, namely tankless water heaters.
Static, dynamic pressure is the same concept as with water. Appliances have a minimum inlet pressure, typically expressed in Inches of water column. (IN.W.C. )
Static, dynamic pressure is the same concept as with water. Appliances have a minimum inlet pressure, typically expressed in Inches of water column. (IN.W.C. )
You lost me at your first word...."volume"!
Maybe that is why is decided to strap on a gun for 25 years and deal with criminals, instead of becoming a plumber?
Maybe that is why is decided to strap on a gun for 25 years and deal with criminals, instead of becoming a plumber?
And to think, this all comes about because the crew likes to stand up and classically miss the bowl when peeing and they don't like cleaning around the tank. Any commercial grade WC with Sloan Flushmate solves the pipe size issue with NO REPIPING WHATSOEVER.
Twowax, your patience is so generous. I just don't have that kind of patience.
Twowax, your patience is so generous. I just don't have that kind of patience.
BriarHouseBrew
Member
wow.
ok, so hope to clear things up a bit and sorry for any frustration this has caused and i REALLY appreciate the time you all have taken for responses. I know better and i should have been a lot more precise with what my needs are.
these would be the items that could potentially be used all at the same time:
Two single stall restrooms, 1 toilet each, 1 sink each.
1 hand sink at the tasting room bar
1 small capacity, low volume dishwasher
1 water tap @ 1/2" line
the brewhouse will be utilized during non business hours.
The City (small rural community) is bumping up my meter to a 1", best i could get. I am running 1" pex thru the building and branching/reducing size where needed to water heaters, sinks, etc. I am hoping this works...if not...i will go with the flush mate(pretty sure that was the recommended item). Also should have mentioned, this was a gut of a 1912 building, bring back new lines coming in and going out. The bump up to the 1" helps me in the brewhouse so...no harm/foul there.
I am not a plumber, just a DIYer...I have enjoyed the knowledge you all have shared, much respect for all the knowledge tradesmen have.
ok, so hope to clear things up a bit and sorry for any frustration this has caused and i REALLY appreciate the time you all have taken for responses. I know better and i should have been a lot more precise with what my needs are.
these would be the items that could potentially be used all at the same time:
Two single stall restrooms, 1 toilet each, 1 sink each.
1 hand sink at the tasting room bar
1 small capacity, low volume dishwasher
1 water tap @ 1/2" line
the brewhouse will be utilized during non business hours.
The City (small rural community) is bumping up my meter to a 1", best i could get. I am running 1" pex thru the building and branching/reducing size where needed to water heaters, sinks, etc. I am hoping this works...if not...i will go with the flush mate(pretty sure that was the recommended item). Also should have mentioned, this was a gut of a 1912 building, bring back new lines coming in and going out. The bump up to the 1" helps me in the brewhouse so...no harm/foul there.
I am not a plumber, just a DIYer...I have enjoyed the knowledge you all have shared, much respect for all the knowledge tradesmen have.
As everyone responding to this post has agreed that the 3/4" line and the 3/4" meter is too small, and the city has agreed to increase the size of the meter to 1" as that is the best you could get, the only issue is the dynamic pressure that will be at the flush valves to allow them to operate. And only 2 flush valves, you are less likely to have multiple flushes. But as you are starting at 80-90 psi from a normal city water supplied system, and running 1" PEX for 50 feet, it is highly unlikely that you would develop 55 psi pressure drop in those 50 feet even with them both flushing at the same time. As such, you will still end up with over 25 psi dynamic pressure at the flush valve, which is more than enough for the flush valve to operate.
I think you are good to go.
I think you are good to go.
I think someone better add up the fixture units per code if it’s being inspected if the original poster wants his flushometers to operate correctly. 
Key points of interest :
How many fixture units are being served ?
What type of fixtures are being served and how many ?
How many fixture units can 1” pex serve according to code 610.10 with the known static pressures and meter size.
Better call Saul……
I’m not sure which plumbing code the OP follows but according to the UPC 1” will not carry the load.
Good day sirs.
Key points of interest :
How many fixture units are being served ?
What type of fixtures are being served and how many ?
How many fixture units can 1” pex serve according to code 610.10 with the known static pressures and meter size.
Better call Saul……
I’m not sure which plumbing code the OP follows but according to the UPC 1” will not carry the load.
Good day sirs.
If you don’t have code book…..
Monett MO, where BriarHouseBrew is located, uses IPC.
IPC excerpts follow:
Yes, there is a sink in each restroom that will increase the WSFU by 3. And yes, there is a bar sink located someplace in the piping system. ANd yes at 37 GPM the velicity will be about 12 fps. But the duration is for a matter of seconds not minutes. And with the conditions listed, and the fact BriarHouseBrew is under IPC, this design seems entirely satisfactory.
IPC excerpts follow:
Yes, there is a sink in each restroom that will increase the WSFU by 3. And yes, there is a bar sink located someplace in the piping system. ANd yes at 37 GPM the velicity will be about 12 fps. But the duration is for a matter of seconds not minutes. And with the conditions listed, and the fact BriarHouseBrew is under IPC, this design seems entirely satisfactory.
It would fail inspection if the code is followed.
It may not operate 100%. Things like this are my bread and butter.
When those flushvalves get starved for water is a revolving door, they run forever. They can’t turn off because the pressure drop, pressure can recover because the valves running constantly. It’s a catch 22. I’ve seen it MANY times. Sometimes a bladder tank can be a hack work around…..sometimes not.
Pex fittings are restricted flow fittings and pex has a lower flow velocity than copper dictated by code.
Peace and love everyone…….peace and love
It may not operate 100%. Things like this are my bread and butter.
When those flushvalves get starved for water is a revolving door, they run forever. They can’t turn off because the pressure drop, pressure can recover because the valves running constantly. It’s a catch 22. I’ve seen it MANY times. Sometimes a bladder tank can be a hack work around…..sometimes not.
Pex fittings are restricted flow fittings and pex has a lower flow velocity than copper dictated by code.
Peace and love everyone…….peace and love
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There’s a 1” copper street 90, same size of 1” copper.
Beside it on the right is a 1” expansion pex coupling.
Compare the two internal diameter.
Crimp type fittings offer even MORE restriction than the expansion fittings pictured.
Beside it on the right is a 1” expansion pex coupling.
Compare the two internal diameter.
Crimp type fittings offer even MORE restriction than the expansion fittings pictured.
With a seating capacity of 49 and an outdoor courtyard at a brew house, I think those 2 flushomters are in for a workout. 
