Overkill electric pressure washer - school me

[The Cobbler]

Any issues feeding the pump with house hot water? Or even "warm" water? Would help the cleansing/sudsing ability of the washer. I could put a thermostatic valve on the inlet to maintain a temp. I'm going to deep dive into the doc you sent now...

hot water pressure washers run cold water thru the pump, and into a hot coil that in turn feeds the gun.
hot water ruins pressure washer pumps real fast

 

[mike93lx]

Made some progress on this. I bought an ancient triplex pump locally, it's huge. It was labeled as a "Whisper washer" by commercial mechanisms, inc. It's got a 1.116" bore and 0.75" stroke on each cylinder. The valve head is solid brass, and the valves are stainless. O-rings on each cylinder. The volume of the pump calcs out at 0.0095 gal/rev. So 3gpm is 315 rpm. Belt drive is obvious. I have to figure out the horsepower needed and get a motor and drive to suit. I am fairly sure i will shoot for about 5 hp on 240v and variable speed drive to match pressure sensor. I am thinking 1000-1200 psi target and vary speed as needed to match nozzle.

Nice. I haven't upgraded yet, but still want to at some point

 

[WildBill]

Grab a ruby nozzle and a adjustable pressure regulator and make a water jet attachment for it while at it, would be cool.

 

[Walkers]

I use https://www.pressure-washer-parts.com/
They helped me rehabs a 2hp hot water pressure washer. It outputs 1500psi at 180*. With hot water it is plenty of pressure, with cold water it is a little lackluster for heavy grease removal, but great for foam cannon, and general purpose washing. Call them up and chat with them about what you want, they are really helpful!

 

[MileHighRover]

hot water pressure washers run cold water thru the pump, and into a hot coil that in turn feeds the gun.
hot water ruins pressure washer pumps real fast

Not necessarily true. A lot of your name brand pumps will handle water up to 140 degrees or so. As I stated earlier in this thread, CAT Pumps offers hot water seals that will push their pump to 190 degrees.

 

[86turbodsl]

I don't have any idea who made my pump. What do you think the risk is running water out of my water heater? It's set at 60c so maybe 120f by the time it gets to the faucet in the garage.

 

[mike93lx]

I don't have any idea who made my pump. What do you think the risk is running water out of my water heater? It's set at 60c so maybe 120f by the time it gets to the faucet in the garage.

@fatfillup is the guy you want.

My guess is that it won't be a good idea

 

[86turbodsl]

I could run a tempering valve if needed.

 

[Walkers]

I could run a tempering valve if needed.

Do you have pics of your current pump?

 

[fatfillup]

Biggest issue with running hot water is destroying the packings in the pump. 120 f water would be ok, just don't shut the trigger off if your machine doesn't shut off when you stop spraying. Running hot water in bypass (trigger shut off but pump still spinning) will kill it quick.

As to pumps being able to pump hot water, I won't sell a machine if I know you are going to pump hot water. I know they claim you can, never seen it done long term with success and I won't sell a machine that I know will be a problem. Let someone else have that headache.

 

[86turbodsl]

Here's the pump i want to use. Bronze head, stainless valves, stainless bores, cast iron everything else.

 

[fatfillup]

Any name on the pump, do you know RPM, volume, max pressure. Can't identify it from looks, not used in my part of the industry.

Speed of the motor it came off of. Rpm is pretty important and I bet that is a slow spinning pump, 800 to 1200 RPM

Do you know the condition of the pump?

 

[W-Cummins]

Hot water is the way to go! It cleans so much better... mine cleans w/o soap 1000X better than my cold machine does with it. There is no comparison, 11 hp electric and up to 300 deg F, and due to a scratch on it I got it new for a song.
William.....

 

[86turbodsl]

Any name on the pump, do you know RPM, volume, max pressure. Can't identify it from looks, not used in my part of the industry.

Speed of the motor it came off of. Rpm is pretty important and I bet that is a slow spinning pump, 800 to 1200 RPM

Do you know the condition of the pump?

The pump has "Commercial Machinery, Inc" cast into it. I'd guess looking at the design, it's at least 1970s. Big and heavy. I calculated the volume at 0.0095 gal / rev. It was hooked to a very small pulley on a 1750rpm 1.5HP motor. I'd guess it's in the 300-400 rpm range. It is designed as a pressure washer pump, i'd guess it's easily capable of 1000-1500 psi. I wouldn't think it would be usable as a pressure washer below that range. I wouldn't be pushing it much harder. I'm shooting for gpm, not pressure. The previous owner was a MDOT station, they said it worked, but they didn't use it anymore. It had both outer cylinders blocked/disabled and the center cylinder had a 1.5" brass check valve and a tube they had down into a barrel for feed. No idea why they didn't just feed it with tap water. The packings and valves all look great. I had the head off to measure displacement.

 

[fatfillup]

Are you staying 110 volt or going to a bigger motor.

1.5 hp will give 1000 psi at 2.2 gpm or 700 psi at 3 gpm

If it is in fact from the 70's. Likely rated 1200 psi or so and maybe 4 gpm at max rpm. A 3 hp 220 volt motor will do 1000 psi at 4 gpm.

Good luck, figure your speed for desired gpm, size your nozzle and watch your amp draw under load.