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Post Info TOPIC: Normal operating pressure of pressure washer


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Normal operating pressure of pressure washer
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Thanks, I would call but Im about to leave for my night job. Sorry forgot those details. Tips for the 4000 4gpm machine are 4.0. Tips for the 3000 2.7gpm machine are the original 2.8. The test was done on a 50ft hose. I will do the test again once I get my 200' hose and reel set up. I use a hammerhead 20" with the big machine, that uses 2 2.0 tips. Same pressure with both wand and surface cleaner.



-- Edited by Stay Clean on Tuesday 12th of March 2013 04:37:17 PM

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Kevin



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I know we all don't use pressure washers on roofs but alot of us have them and use them elsewhere. I got a pressure gauge yesterday and tested both my machines.

One is a honda 4gpm 4000psi belt drive unit (no stickers or numbers on machine, thats just what I was told). Test results: With the unloader fully tight the operating pressure was 3500psi under load with all the tips but the pressure would jump to 4800psi when I let off the trigger. I adjusted it down so that pressure only jumps to 4000psi and operating pressure is still at 3500psi. If I adjust any lower I will start to lose operating pressure.

The other one is my old 3000psi 2.7gpm. Test results: Same as above. Operating pressure is 2500psi and jumps to 3000psi when I let off the trigger.

So does this sound normal for pressure washers? I've see larry's video on adjusting the unloader so this seems normal to me.

Is my machine really a 4000 or 3500? I think 4000 because both machines have operating pressures 500psi lower than they are rated for.



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Kevin



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What size tips are you using in each machine, and how long are your pressure hoses? Feel free to give me a call.



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Sounds like you're on the right track. The pump on the bigger machine is most likely either a 3.5gpm @ 4000 or a 4gpm @ 3500. Both sizes are pretty common. Either one will make you the money . I get a 200 psi drop on 200' of hose. The pump should have a name on it somewhere, along with a serial number. I used one of those machines to put food on the table when I first started. Not the fastest machines in the world, but more than capable to do the job with the right person behind the wand. I'm always glad to help if I can. Congrats on the new setup!

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Thanks for the input. Yes it's not the biggest or fastest machine but I've got to start somewhere. I picked up this machine for $500 with a new 50ft hose and new gun/wand/tips... can't beat that deal. Maybe one day I'll be able to step up to the high hp high gpm machines you all use. Until then this gets the job done.

Yes Chuck the unloader was slam bang tight. It will never go that tight again. Im keeping it at 4000 or less. 4800 is too much strain on this system.

Marcus, if you had my machine what psi would you set it at for maximum cleaning power (mostly for running 20" cleaner)? Sounds like less pressure = more water flow = better cleaning. I will do tests at 2500, 3000, and 3500psi to see what works best.



-- Edited by Stay Clean on Thursday 14th of March 2013 02:36:20 AM

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Kevin



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If with a "PROPERLY FIT" unloader your gauge jumps to 4800, that's because you have it slam bang tight. When set to 4000 it's set right. You can not go by what tip is in, you go by where it stops at-as you have done. I have an 18hp 4000 psi machine, but turn it down to 2500 psi. I don't want to blast most things, I want the extra water flow. You can't have high water flow and high pressure-CHOOSE.

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You get better cleaning with more flow and less pressure on flatwork or house cleaning.  That is why I use 24hp hondas @ 8gpm pumps and 3500 psi for flatwork and 13 hp hondas @ 8.5 gpm and 1500 psi for cleaning houses.



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