1 1/2" water line?

[Eric H]

I have an existing 4 bay SS that is being converted to 3 SS and 2 IBA. The existing water line is 1 1/2". Will a 1 1/2" line provide 62 GPM at 90 psi? I told the contractor to I wanted to upgrade to 2" based on recommendations from my distributor but it looks like it will be more costly than originally anticipated. I found a chart the show a 1 1/2" pipe will flow 82 GPM but this doesn't take into consideration any restriction from meters, back flow devices and pressure regulators.

The info from Badger meters says their 1 1/2" meter will handle 120 cpm http://www.badgermeter.com/Badger-Files/PDFs/Water-Utility/RDM-LG-00060-EN.pdf?

Looking for some real life experience here...the guy from the city simple said "You should be all right"

 

[MEP001]

It should be okay if there's a consistent pressure of 90 psi, but it's borderline. I assume you're going with two touchless autos? I can tell you from "real life experience" that the guys here who built with two auto bays wish they'd just added another self serve instead.

 

[Greg Pack]

Depends on the area system health. Static pressure when there is no flow means little. Residual pressure when water is flowing will be more important. With a 1.5 inch, there is not a lot of room for error or much friction loss. every time water make a change in direction it loses energy. On top of what you mentioned, softeners can cause a 15psi loss at rated flow rates.

You can cheat a bit with some autos by keeping the big valves partially closed to keep the pressure form dropping. Open it just enough to keep up with the wash. The auto holding tank serves as an additional reserve.

Some hints will be to look at the color of the closest fire hydrant. Most department color code their hydrants. If it has a green bonnet, it has been flow tested to at least 1000-1500 gpm. A blue is 1500 GPM or greater. Orange is 500-1000 and red is 500GPM or below.

Bottom line You might be borderline on busy days. I prefer a bigger pipe, but a booster pump and tank may be worth looking into. At least go ahead and plan room and the electrical space for one.

 

[Randy]

I’d replace the water line with 2” poly and have the meter replaced with a 2” meter. The meter is very important as it will restrict the flow more than one would think. If the water line is galvanized steel pipe then you’re going to have problems. Pumps and holding tanks are a real pain to deal with.

 

[robert roman]

“Will a 1 1/2" line provide 62 GPM at 90 psi?,….told the contractor to I wanted to upgrade to 2" based on recommendations from my distributor but it looks like it will be more costly than originally anticipated.”

That’s not an easy question to answer.

For example, distributors estimate full load amps when designing the system. Similarly, they use gallon per minute specifications for equipment and systems to estimate total water consumption for the site.

For example, a basic touch-less machine may specify 1” water line at 40 PSI and usage rate of 22 GPM. However, across range of wash times, 3 to 5 minutes, total consumption may be 50 to 70 gallons.

Whereas a basic friction machine may specify 1” water line at 40 PSI and usage rate of 22 GPM. However, across range of wash times total consumption may be 35 to 45 gallons.

So, if the distributor is recommending 2” water line, the reason must be he is concerned the site may run short on volume of water (GPM) with 1.5”.

At standard pressure, the difference in volume of water (GPM) between 1.5” and 2” line is 75 percent.

Based on investment you are making, why compromise outcome by trying to jury rig the system.

Follow best practices and spend the cheese.

 

[rph9168]

I agree with Randy and Robert. I think you would be pushing your luck with a 1 1/2" line. The last thing you want to happen is to run out of water on and automatic.

 

[soapy]

I have one location that has 2 IBA touchless and 3 SS bays that is fairly busy that uses a 1 1/2 inch water line. I added some additional holding tanks to each IBA, about 75 gallons per IBA. This gives me plenty of water to run on the busiest days with no problems. You can spend $200 for holding tanks and operate without problems. Another solution is a repressuraization pump that will actually draw more water through your water line but I would just add more water storage capacity for your IBA.

 

[Jeff_L]

Are you open to another idea? I feed both my IBA's with 2" pipes from my holding tanks. Thus, I don't depend on the city. My holding tanks are primarily fed by the reject from my spot free system, but they also have a 1/2" tap water line activated by a float on those busy winter days. Never had an issue of running out of water my "tank" is seven 55gal drums on their side, on a rack, tied together via PVC connections. They are usually about 1/3 full at all times.

 

[Greg Pack]

Are you open to another idea? I feed both my IBA's with 2" pipes from my holding tanks. Thus, I don't depend on the city. My holding tanks are primarily fed by the reject from my spot free system, but they also have a 1/2" tap water line activated by a float on those busy winter days. Never had an issue of running out of water my "tank" is seven 55gal drums on their side, on a rack, tied together via PVC connections. They are usually about 1/3 full at all times.

Yeah, with a a big enough tank, you could run off a residential line on many sites.

fifteen years ago I built a wash, and in the latter stages we discovered relatively low water pressure. The main was in the middle of the street, and it would cost some serious money to run a a bigger line. I just gated back the auto float valve and disconnected the low pressure switch on the RO. I ran like that for several years with no major issues, and it was a busy site, with the single auto averaging over 2K cars per month.

 

[Eric H]

Plumber and I did a nonscientific flow test this morning. I left out of my origional post that the 1 1/2" waterline then goes thru a 3/4" water meter and then is 1 1/4" for the pressure regulator and backflow preventer. Surprisingly, we were able to get +/- 50 gallons per minute! We are going to install a 2" backflow, regulator and 1 1/2" meter and retest before we pour the floor and repave. As long as we have enough flow we should be all set.
I'll let you know how it goes. Thanks for the help

 

[Waxman]

Plumber and I did a nonscientific flow test this morning. I left out of my origional post that the 1 1/2" waterline then goes thru a 3/4" water meter and then is 1 1/4" for the pressure regulator and backflow preventer. Surprisingly, we were able to get +/- 50 gallons per minute! We are going to install a 2" backflow, regulator and 1 1/2" meter and retest before we pour the floor and repave. As long as we have enough flow we should be all set.
I'll let you know how it goes. Thanks for the help

with the touchfrees, the water used by your main pump is not 'on demand' from city water; pumps are fed by a holding tank that regenerates as level in that tank drops.

since you got 50 gpm with your test, i would run with that and leave the option open to store more water in reserve for your touch frees. I can get you the 150 gal. totes that are stackable for very little money and that would be more than enough to hold in reserve and recover while both machines crank out washes this winter.

 

[mrfixit]

The problem is significant pressure loss. When every device is running at the same time. If your depending on city pressure... If you've got softeners, ro, ect. Its easy for one thing to restrict the volume or draw down.. When one auto kicks one you may loose half your pressure. If your regulating down to even it out flow may be slow.

Pressure drop, if you can control that you may be OK. 50 gpm to one device at 80psi(?) city pressure = 25g to each auto at 40 psi.. Keep dividing it out, unless you go holding tanks.

With 11/2 line, Softeners are probably the biggest restrictor if they are not sized properly.. I think most company's have a tendency to undersize as they don't understand how much water we use on busy days. They look at your line and just install a 1 1/2 system when it may take more tanks to get you the real flow during peak time *while regenerating. We have 2 kinetico cp 213s od's = 4 resin tanks and it maxes at 52gpm

Nothing worse than later wishing you put in 2". What if you want to add something.. Then your struggling or putting in more holding tanks..

I have 1 1/2 and I am having another 1 1/2 installed from the main just for my auto. Its been a lot of headaches for years because they didn't use 2" ! If it were two inch they would have used a bigger softner for example and had less restriction as well.

We should be peaking at 80gpm. But I don't seem to get more than 52 in real life according to the 2" smart meter.. That's when production drops and we start to run out of water.

10 years from now your gonna kick yourself. When you find the cause to your problems... Real experience.. Never undersize pipe. Some day....

While your conditions may be different than mine that is our experience. Ymmv

 

[cap732000]

I had the same problem I did what has already been mentioned I have a big poly holding tank and it has done me we'll! Cfcw is spot on In his assessment in my opinion!@

 

[mac]

A couple of things to think about. It used to be common to run all of the water through a softener. I now just use the soft water to feed the chemicals and the RO. You'll save a lot of salt and shouldn't hurt the wash quality. I also don't think it's a good idea anymore to put in two touchless machines. The new friction ones will clean better and use much less water.

 

[pgrzes]

I have a 4" line from the main, probably about 150 yards away. From the 4"line it comes into my equip room at a 1 1/2" line. 1- Washworld HV, and 7 self serve bays. 2 ro units. On a busy day I have major problems. I have about 500 gallons of reclaim and reject water stored in attic. On a busy that all disappears. I am looking into running a second 1 1/2" line into my self serve equip. room. If I can tee off of the 4" line it should provide more then enough water. I have 2 equip rooms separated by 3 self serve bays. Unfortunately I cant share ro and spot free water between the 2 rooms. (not yet anyway) If you can go bigger do it now not later!!!