Orifice size

[Dynoguy]

I know on electric pressure washers they like to use a 1.1 size orifice on foam cannons what size orifice would you use on a gas pressure washer ?

[grovlet]

MTM has a nozzle size calculator - but it's simple = Just need to know GPM & PSI:
MTM Nozzle Size Calculator (https://www.mtmhydroparts.com/pages/nozzle-size-calculator)

[bofh]

Nozzle size and orifice size aren't the same thing...

[SWETM]

How many gpm is your PW pump rated for and what's the working psi from the PW?

I have a chart or diagram that's in swedish and we use the liter and bar measures on our PW specs. But can convert it to your gpm and psi. Also look up the max psi the foamcannon can handle and the PW spray gun handle and the hose on your setup. Just so you don't have any bottleneck on those. If you want to have a certain psi from the nozzle tips I can look up that too or if you use the linked calculator above on the MTM website. Depending on the gpm from the PW you useally want 1500psi-2000psi. To have a great cleaning ability from the PW. On the foamcannon you want to use the smallest orifice you can get away with. But you should not get over the psi from it that the PW pump or the equipment from the PW to the foamcannon can handle. This can be especially important on a gas PW. The electric PW starts to pulsing when you gets over the psi limit. On a gas PW that's not always the case and say the your foamcannon or PW hose is max rated for 3000psi. And if you a to small orifice the psi can easily go up to 4000psi or more depending on the specs on the PW.

[Dynoguy]

It is a Landa Pressure Washer it has a 5 H.P. Honda motor on it but does not give PSI or GPM on it.

[briarpatch]

It is a Landa Pressure Washer it has a 5 H.P. Honda motor on it but does not give PSI or GPM on it.

what model? The specs for some of them are shown on the Landa website

[Dynoguy]

I have an older model it is not shown on there, I would guess it has a 2.0 GPM on there. Not sure what orifice size I should try, I tried a 1.1 which is all I have but the foam does not foam much and when I adjust the foam cannon it does not change the foam.

[SWETM]

You have mesh filter in the foamcannon somewhere and try to get the chemical mix setting to get loose and so it adjust the foam. Sometimes these things can get stuck if you don't rinse them out with clean water afterwards. Some car soap and prewash foams are worse than others to do this. My nicer and more expensive foamcannon just did this. So will have it taken into bits. And clean it up.

If your PW has 2gpm the according to the calculation is just a little too little of useing the 1.1mm orifice in the foamcannon. The otherwise standard 1.25mm orifice should work too. It's up to 2.3gpm on that orifice. And the max is 1.85gpm on the 1.1mm orifice. But it's not a problem to use the 1.1mm orifice in the foamcannon as with 2gpm you have a 1800psi from the foamcannon.

Proberly your chemical mix setting is stuck on the least chemical mix setting on the foamcannon. If you go up in the size of the orifice in the foamcannon you will get a less dense foam if your PW don't have enough of gpm. The problem is with a too high of psi from the foamcannon you put a lot of stress on the PW pump.

What car soap or foam do you have? And what dilution in the foamcannon bottle do you have?

Useally the foamcannon dilute the chemical in the foamcannon bottle on the highest chemical mix setting 1:15-1:20 and the lowest chemical mix setting 1:45-1:60. So have that in mind when you dilute the car soap or foam in the foamcannon bottle.

[Dynoguy]

I found out today my pressure washer is 3300 PSI and is 2.3 GPM. What orifice size do you recommend ? I have a 1.1 but that is to small it came from an electric pressure washer.

[briarpatch]

My advice would be to go to the 1.25mm

[SWETM]

I found out today my pressure washer is 3300 PSI and is 2.3 GPM. What orifice size do you recommend ? I have a 1.1 but that is to small it came from an electric pressure washer.

The 1.25mm orifice will be perfect for you.