Build a 42 gpm pressure washing unit?

Two recent discussions brought up jumping two machines to increase GPM. I found a ton of pumps between 18 gpm and 42 gpm. But the horsepower required can be 33 HP to 50 HP.

So here’s my question. What engines are they attaching to these pumps? I’m not googling the correct terminology nor am I finding 50 HP engines. I found the 33 HP Kohler, but where are the bigger engines?

I’ve seen pressure washers with fan cooled radiator engines.

What gpm necessitates an increase to 3/4" pressure hose?

So many questions.

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3/4” hose sounds heavy.

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Diesel 3 cylinder kabota. I’ve seen a few floating around eBay before.


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I’m looking at 3/4" for 250 feet pressure hose for $5k. Holy moly.

$5000 for 250 feet of hose?

Id rather take a 3 foot wand in my bypass. Thats is crazy talk.


Gotta spend it to make it!

My brother had a guy who worked for him that tried explaining to me that at his old job they used 10k psi pressure washers in these silo things and I never really paid attention to what he was saying because it was before I ever even got in this business, but what do you know…

I’m just interested in the logistics and engineering of it, but who knows. Maybe someone will come along who is interested in building it.

A 42 GPM will only run 23 minutes off a 1,000 gl buffer tank. What possible water supply besides a lake could supply that?


My cousin has ran one. They can cut metal. The wand looks like an AR


Fire hydrants all day!


Didn’t even think of that part yet… maybe multiple hydrants

Off of what size hose? Certainly not 1"

2.5 inch

I’m not picking up what your laying down?

There are multi high gpm and high pressure pumps used for cleaning not transfer. You built one of 1000 different combinations in your example. The high gpm/high pressure machines are what I’m interested in learning more about.

Your really diving into this parking garage head first.

Haha not really. Flat work bores me to tears. But who knows? I may need to know this stuff in the future and it’s archived right here.

A long time ago I worked in a factory. We had some 26 GPM high pressure pumps but they weren’t connected to wands or surface cleaners, they were used to pressurize sprayers and provide other pressure applications in the manufacturing process. I am having a hard time seeing what the use for an industrial pump is in the type of cleaning we do.

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