Newbie needing help (Surface Cleaner Question)


You have a 4000 psi machine. On the chart look along the top and you’ll see “psi”. The numbers below are how many gpm the nozzle puts out. So, since you have a 4000 psi machine, and your surface cleaner has a 2 nozzle bar, you want to follow down until you see “2” (2 nozzle x 2 gpm = 4 gpm which is what your machine puts out). Once you find the 2 follow it all the way to the left and you get your nozzle size. The gpm won’t always be exact. In your case instead of 2 it’s going to be 2.12. 2502 is the correct size. (25 is the degree or fan of the spray. 2 is the nozzle size. that’s where 2502 comes from). If you were to use the 2504 each #4 nozzle puts out 4 gpm. (Follow the number 4 to the right and up to the 4500 psi. It’s 4 gpm). If you used a 4 gpm in each nozzle that’s 8 gpm total which is twice as much as what your machine puts out.

I’d probably take it back and tell the guy he should’ve sold you a 16" As mentioned above they recommend 4" per each gpm. Either that or bring your machine too and tell him to get it to work. If it doesn’t work correctly he pretty much has to take it back as long as you haven’t had it all that long. If some place sold me something that didn’t work correctly I guarantee they’re going to make it right. Most decent businesses would be more than happy to make it right.


So when looking at this chart I have figured out Thanks to you guys how to see the right tip on the chart. But how do you know what the tip is on the chart for example 2502 is for 4000 4gpm??


You just look at the last 2 numbers in the nozzle size. As mentioned earlier, a 2502 is a 25° spray pattern with #2 orifice. For sizing nozzles on surface cleaners, first divide your flow rate from the machine by the total number of nozzles on the cleaner. (You can do the division later, but I think this makes a little more sense for newbies)

So in your case 4gpm/2nozzles=2gpm going to each nozzle.

Then look at the nozzle chart to see how much pressure you want hitting the concrete. 4000 psi can be overkill for residential concrete. So you might want to go with next size up, 2.5 orifice nozzles (look for 25025/2502.5 nozzles). That would drop your pressure down around 2500 psi



? So if the surface cleaner is 4000 psi and having the regulator wide open is to much for residential shouldn’t I just dial back on the regulator??Or do you just leave your machine wide open and change tips??


The green or yellow flexzilla?
Are they both the same?


Change the tips to change the pressure, as long as you’re still using one that gets you 4 gpm.

Green flexzilla serves me well.


leave the unloader wide open and use tips to change pressure on surface


Ok so I went back he actually changed out for the 16 inch no has 25002 tips on it it so I should be good to do residential then?


It is also for 4gpm


Thank you very much. I was wondering cause one guy told me that 4000 psi could be to much for residential. So I can change the pressure of my unit for surface cleaner by getting different tips.


Yes it is he didn’t give me a hassle at all. So with the 25002 tips I should be perfectly fine to do anything residential?


So looking at chart if I wanted 3500 psi chart shows 1.87 and nozzle 2 how do I learn what what the tip number is to order?


Which size nozzles came with the 16"?


Just noticed in your picture that the down stream injector is on your machine try removing it from the
line when using the surface cleaner. it should run the surface cleaner better…




Thank you


The 16 inch came with 25002


Should you be sizing nozzles for your max operating PSI or more towards your max operating GPM?
For residential, which is more cleaning power, greater PSI or greater GPM?
Is there a golden number for PSI you should work from, sizing your nozzles for the greatest GPM at that rule of thumb PSI?
IE: If 2500 PSI is the magic number for residential concrete cleaning, then you would work to get the optimum GPM while maintaining that magic 2500 PSI?


Your gpm should never change. If your running a 8@3500 machine you should always be pushing out 8gpm the only thing that will change is how much pressure you want to be hitting the surface. the pressure hitting the surface is done through the nozzles, but the nozzle size should always allow max flow. Never go down to nozzles that would restrict the flow of your machine.

I have my surface cleaners set up to run about 1800 psi(or lower depending on hose length). It really does not take much pressure to clean concrete, plus it allows me to wash other sufaces without having to changes the nozzles out every time. You dont need max psi to clean most things.

I think people get to caught up in the numbers, your pressure will change depending on a lot of factors and trying to have it “perfect” will just lead to frustration.