Help me understand lowering pressure with nozzle size

Thank you

All good stuff right there.

Help me with this nozzle chart please! I just need to know what size orfice i need to ds a house on a 4gpm/4000psi pressure washer, i need nozzles 0,5,15,25

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Just go on the PT website and order the downstream nozzle kit for a 4gpm machine. It really is that simple (coming from a guy who is also flummoxed by the nozzle charts)

Atlas Services
Exterior Cleaning Specialists
North Carolina

What I understand it as is first two numbers is spray pattern second two is orfice size
So I think it would be like a 2540
Would be 25 degree pattern at 4 gpm I think

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Ok my turn.

I am ordering a 5.5gmp 2500 psi machine from pressure tek along with the 5-6gpm jrod kit which comes with 0040(soap high), 0015(rinse high), 2540(soap low), 2515(rinse low).

If I am correct, these tips are way too strong to clean a house. A 2540 nozzle would give me a 25 degree spray but the 4.0 orfice size would go beyond the PSI that this machine is capable of, essentially maxing out my psi at 2500 at the tip of the nozzle. It is my understanding that when doing a house, you want less than 800psi.

Unless of course the 40 in the 2540 is an actual size of 40 and not 4.0. In that case I would get under 100psi…

studying more it makes sense for the second scenario to be correct and as @marinegrunt mentioned if it were 25045 then my nozzle size would be a 4.5. OK, got it.

Well since I already brought up an old thread. What PSI do yall wash a house at?

@SureShot I am a little confused about the table above as well, but considering I just bought essentially the same jrod setup I’m hoping your second scenario is correct. Looks like I will be under 100psi for wash and under 500psi for rinse. I did but what the guys at Pressure Tek suggested so I assume they know what they are talking about! Haha

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Correct. At first you were thinking 2504 (2504.0) or 25045 (2504.5) instead of 2540 but you caught yourself. Some just always label them using 5 numbers 25040 instead of just 2504. Half size orifices are always labeled with 5 numbers 25045. Just always picture a decimal point after the 4th number and it’ll make it easier.

Your 0040 and 0015 won’t have any fan pattern. It’ll be a straighter stream which will allow you to get up high. The 25 degree tips fan the pattern out more. You don’t want to use the 00 when you’re down low and up close. That’s why you use the 25 degree which will fan the pattern out more. Some use an single adjustable nozzle and just fan the pattern out on their own. Watch Racer’s video. He uses the M5 when washing houses.


On 4gpm, I personally think the 0010 rinse tips are still too much pressure. It doesn t speed anything up using them. I suggest rinsing with the same tips you wash with.


I use the 0010 constantly. I need it to rinse high. By the time the stream gets to 20’ there significantly less pressure hitting the house. I don’t have a remote to switch my injector off and I’m not walking back to my trailer. I switch Jrod nozzles depending on height.

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Sorry to bring this up again…

I have the 20" Hammer Head with a 5.5gpm 2500psi machine. The surface cleaner came with 2502 tips, looking at the chart, with those tips I am getting about 1.5gpm per tip at 2500psi. So what I need is 25035 tips which would put me at about 2.75gpm per tip and ill be getting 2500psi at each tip, Is this all correct? I know ill lose some pressure due to numerous factors (200ft. hose, fittings, etc.)

As for the J-Rod:
0040 = 250psi, 0015 = about 800psi, 2540 = 250psi w/25degree fan, 2515 = about 800psi w/25 degree fan.

I know i’m beating a dead horse for some of y’all but I have a house wash coming up and I would like to at least look like I know what i’m doing…

As usual, the help and patience is much appreciated!

Your surface cleaner nozzle selections is correct.

Your J Rod nozzle are for the most part correct (my chart says a little less psi on the #15. Most use the same nozzle(s) to both soap and rinse. That way you keep the pressure “low”. In order to do that you need a way to either bypass or stop your down stream injector from drawing soap (just a simple ball valve). On my 5.5 machine my main 3 nozzles for a house wash are 4040, 1530, and 0040

Alright so I need new surface nozzles, I thought the water supply was a little low while doing my patio. For now I’ll have to shut off my washer until my ball valve comes in to remove my DS injector. All charts seem to vary a bit, I was using he one from Pressure Tek. Thanks @Donte55

Just to be clear, i dont remove my DS injector. I have mine set up with the bypass kit so that i get more flow for surface cleaning. Others just have a poly ball valve on the soap line going into the injector to just stop it from pulling soap. In both situations the injector is still hooked up 100% of the time.

I get that. I figured removing the injector completely would increase flow…

This is what i use

Or you can have made up like below which helps your flow even more


Wait… so are those tees, check valves? I know literally nothing about bypass injectors except that you can turn off soap.

How do you clean your injectors out after downstreaming?