LETS TALK GPM why and Where? How Much PSI is to much or To Little

[tomtucson]

I meant runoff of the sidewalk, not the property! We hook up 2 hoses to run 2 machines. Very rarely have any water issues with 50 gal tanks, the actual spray time is so fast. Larger tanks will be part of the new system.

 

[Christopher]

I really could have used a huge surface cleaner today, had a huge driveway to wash and the main surface cleaner died on the job, a pressure hose blew out a foot from the end and I had to finish the job with the classic with modified handle so it was not too bad.

That 48" surface cleaner would have worked great on this job.

 

[CL Scott]

Horizontal cleaning depends on my environment and wash water control hazards

If I washed houses I would want a fire hose

Oct event San Diego free free text me for more details !!

Funny you say that about the fire hose... I fill up at fire stations quite often. While talking to one fireman "the squad pump guy", he tells me those trucks run at about 200 gpm for an average fire, and have to potential to hit 1500 gpm... Imagine that...

 

[Ron Musgraves]

Funny you say that about the fire hose... I fill up at fire stations quite often. While talking to one fireman "the squad pump guy", he tells me those trucks run at about 200 gpm for an average fire, and have to potential to hit 1500 gpm... Imagine that...

View attachment 26544

Someone Built a Fire Truck Once

 

[ABC]

Yeah. My hot water is 4 gpm. I'm looking to get 8-10 gpm. The question is hot or cold. Of course there's about $4k in price to add hot water. Sounds like adding a cold 8-10 gpm is the way to go all the way around - saves the higher investment, saves the ongoing investment - on chems!

You are going to outgrow your trailer in about 15 minutes CL. lol.
Don't forget that there are products known as "Hot Boxes" that connect to whatever unit you are using after matching the specs.
They run around 12-15 hundred $$$$$. That's a big savings if you go in that direction with a 10gpm unit.

 

[CL Scott]

You are going to outgrow your trailer in about 15 minutes CL. lol.
Don't forget that there are products known as "Hot Boxes" that connect to whatever unit you are using after matching the specs.
They run around 12-15 hundred $$$$$. That's a big savings if you go in that direction with a 10gpm unit.

I'll be sure and let you know before I cash out.

 

[tomtucson]

You are going to outgrow your trailer in about 15 minutes CL. lol.
Don't forget that there are products known as "Hot Boxes" that connect to whatever unit you are using after matching the specs.
They run around 12-15 hundred $$$$$. That's a big savings if you go in that direction with a 10gpm unit.

Adrian are you talking used? Thats a low price for 8+ gpm, I could use one.

 

[Paul Kassander]

Like Jerry said there are a lot of variables. First thing to consider is the work you are going to do and what is all involved. Hood cleaning for example really never over 5 gpm and most of the time 4 gpm. pressures can range from 1500 psi to 4000 depending on the job and what you are cleaning. For most Residential work I would suggest nothing less than 4 gpm but 5-8 gpm is ideal...pressure range from 1500 to 3000 psi. More gpm is better but you also need to take into account your water source and buffer tank capacity working faster is no good if you have to stop and wait for the water to catch up every 2 min.... Fleet washing 5-8gpm is ideal pressures from 2000-3500. I don't recommend more than 8gpm on fleets because you can only move so fast when washing a vehicle and water is gold. Most locations don't have water or it is far far away from where you do the work so you only have what you can carry and you don't want to waste it. And runoff can be a concern if you need to recover that's a lot to haul back. For sidewalk cleaning 5-10 gpm at 3500-4000 psi in most cases the 5 gpm is adequate but the gpm will go up the more surface area you have to clean. For a parking structure 10 gpm is ideal you will be able to push the dirt further and faster and cover much more ground actually using less water. ...there are really a ton of other factors involved as well so its tough to make a one size fits all but as a general rule I tell people don't go less than 5 gpm and try to stay between 2500 and 3500 psi and you can do just about anything you want.

 

[JDhomeservices]

You are going to outgrow your trailer in about 15 minutes CL. lol.
Don't forget that there are products known as "Hot Boxes" that connect to whatever unit you are using after matching the specs.
They run around 12-15 hundred $$$$$. That's a big savings if you go in that direction with a 10gpm unit.

Where are you finding hotboxes for that price?

Sent from my DROID RAZR using Tapatalk

 

[snagtooth]

OK yeah.. this is a HUGE topic, and EVERYone needs to understand the basics AND variables..
as there are SOooo many variables

start here.. water flow restriction in 100ft of HP hose with fittings..
5. gpm in 3/8 is about 100psi in 300ft of hose with 3500psi unit @3200psi, 4000psi y= 3700psi.. =grafitti removal (@ 200 degr.)
6.5gpm .. .. is about 200psi in 300ft of hose with 3500psi yields 2900psi, 4000psi y= 3400psi.. =gum removal .. (.. " " )
8. gpm .. .. is about 300psi in 300ft of hose with 3500psi yields 2600psi, 4000psi y= 3100psi.. =sidewalk cleaning ( " " )
10 gpm .. .. is about 400psi in 300ft of hose with 3500psi yields 2300psi, = house washing

8. gpm in 1/2 is only 60psi in 300ft of hose with 3500psi yields 3320psi, 4000psi y= 3820psi
10.gpm .. .. is about 90psi.. and a fuel savings of about 30% over "squeezing it" through a 3/8" hose.
14.gpm .. .. is about 150psi

next is relative effectiveness..
generally.. Flow is about "WorkSpeed" and pressure is about "Quality of Clean"
..but by "delivery of" effectiveness..
you're better off with 6.5gpm at 4000psi than 8 @ 3500 .. and you will save HP fuel .. 6.5@4000= 18.2hpC 8@3500= 19.6hpC
..but..
if you want to use 1/2" for the first 200ft, and go 100ft more with 3/8"..
.. 8gpm@3500psi delivers 3100psi ..so 8gpm is better than 6.5gpm@3500 delivering 3200 from 3500psi unit,
.. but if a 6.5gpm 4000psi unit, which has delivery of 3400psi in the lighter 3/8" hose..
we're going to talk heating-fuel costs..
using 6.5gpm@4000psi system costs you about 10% less gasoline, and 20% less diesel to heat it.
..If running 20gl of fuel per day, that's about $20. back in your pocket ! every day !
that's a $5000 vacation, per machine every year !
..and you pull the lighter hose !

So.. are you a 5ft10" 180lb man, or 6ft2" and 230lb ?
performance can relatively "kick yer A$$" if you don't do the math,
and "the lack of performance" .. can hack yer profit$

If you want to own efficiency.. CALL ME !
I will NEVER waste your time, nor a nickle of your money.

I always say "the Jobsite tells YOU what it needs"
and.. don't waste fuel and HP on "mis-delivered" flow.

So for you guys that will add you criticisms and suggestions in here..
make sure your examples of "performance" include..
what size, and how much hose is on your reel,
and how much fuel you buy to do the example day's work.

Time is money, but efficiency is about keeping more of it.

Jerry where do you get some of your tech formulas from? Will you share your source for some of the formulas you use on your tech wizardry? Thanks