pressure washer outputs?

[plainpainter 217]

Just curious - I see some impressive numbers on this website when it comes to pressure washers and their G.P.M's. I read about somewhere the average municipal water supply is only about 5 G.P.M. in residential areas. So I tested my hose - and it turned out to be about 4 G.P.M. So is it practical to have pressure washers much beyond 3.5 G.P.M. for residential use? Are the larger numbers I see being posted - for commercial work with higher output source of water?

-Dan

[Neil_Asheville 114]

Dan - many of the heavyweights here that run 5.5gpm and up are pulling from a rig-mounted supply tank, not a municipal line or well. You'll hear them often referred to as buffer tanks, meaning the tank serves as the 'buffer' in difference from supply output to what the pump is pulling.

/neil

[PLD 14]

It is not only practical, it is a much better way of working. 5.5 is so much easier that I hate it when I get the 4.0 and my helper gets the 5.5.

As for flow, we do 3-400 houses a year and I have never had a 4.0 or a 5.5 starve on a residence. I typically find that a residence will over supply a 5.5 on one spigot and oversupply my 4.0 & 5.5 when I connect to two spigots. Keep in mind that spigot will flow faster when connected to a sucking pump than it will to open air because the pump presents a negative pressure sink for the flow.

More often than not, we give the tank a 75-100 gallon head start and run two guns (9.5gpm) without water worries. If it is a problem, bypassing the hose reel and running two lines to seperate spigots fixes it.

[mas3372 14]

I have a 5.6 gpm machine and a 300 gallon water tank and found I was never going in the hole more than 20 gallons. I took off my 300 gallon tank and now I use a 55 gallon drum on its side. Plumb the tank to my Pressure washer and the supply hose to the drums top with a float valve. Its is perfect for what I need and I now tow 2000 pounds less. The more gpm the better. I am new to this but that did not take long to figure out.

[plainpainter 217]

Thanks for the answers. So I'll have to look into a tank if I want to get more serious with this stuff. For now I am running a Craftsman 7.0 horsepower that is delivering 2.7 GPM @ 2900 PSI. Even now I notice sometimes the line goes 'dead' in that there isn't enough water for like a moment for the pump to pressureize - I imagine it has something to do with air in the lines or something.

-Dan

[Anthony G 14]

If you continue that practice......you will damage your pump from cavitation. Any time that you are starving the pump you can be damaging the internals. I have had painting contractors call me, due to my water tanks, and I would sub that from them just so they could finish the job.

[mas3372 14]

i have a 300 gallon tank for sale in rhode island if you are interested. I may be able to deliver it on my next trip to my inlaws in newburyport. Tank brand new is around $600 with frieght, only used it for 1 month. Yours for the low price of $350.

[PLD 14]

Thanks for the answers. So I'll have to look into a tank if I want to get more serious with this stuff. For now I am running a Craftsman 7.0 horsepower that is delivering 2.7 GPM @ 2900 PSI. Even now I notice sometimes the line goes 'dead' in that there isn't enough water for like a moment for the pump to pressureize - I imagine it has something to do with air in the lines or something.

-Dan

Barring mechanical failure, that's either air in the lines or supply problems. At 2.7gpm, you should just about be able to run that puppy off a sink faucet. I run 4x that with no problems. Call me if want and we can work it out.

[PLD 14]

i have a 300 gallon tank for sale in rhode island if you are interested. I may be able to deliver it on my next trip to my inlaws in newburyport. Tank brand new is around $600 with frieght, only used it for 1 month. Yours for the low price of $350.

Sorry to jump in on you, but that reminds me! It probably won't for Dan (much too big, killer freight costs) that I've still got a 525gal for sale in the bargain basement.

[PLD 14]

If you continue that practice......you will damage your pump from cavitation. Any time that you are starving the pump you can be damaging the internals. I have had painting contractors call me, due to my water tanks, and I would sub that from them just so they could finish the job.

Anthony is right. If nothing more, get a 15 gal chem drum and plumb it in. It'll give you about 5 min buffer for the dips, and you can pipe the unloader into it giving youself the ability to idle for qute awhile w/o damage.

FWIW, redirecting unloader output is about 90% of the reason I use a tank.

[plainpainter 217]

So what do you guys think, is a 300 gallon tank a good thing for me to have?

By the way, I love Newburyport - that town is a painter's dream! Lots of nice old homes that are meticulously kept up.

-Dan

[PLD 14]

on a 2.7? I wouldn't go larger than a 125.

[mas3372 14]

newburyport is beautiful. For sure. Lots of money as well to help pay people like you and I. I agree a 300 gallon is over kill to just supplement flow. It would however be useful to do small jobs with no water supply. If you always have a water supply, 100 gallon tank is more than enough.

[Kory 14]

Keep weight in mind a gallon of water is 8.37 pounds. That can make a huge differance.Do you have something that will pull that weight?

[mas3372 14]

The wieght is why I down sized. My truck can pull it on the tandem axle trailer but I never used that much water to catch up for my pump so saving the weight saves gas. No to mention, much more room on the trailer.

You can also do what I did and try to find a 55 gallon drum, usually at a car wash. Theser are great because they contained soap so it is not a hudge deal to clean out. Just turn it on its side, screw in a 2 inch pvc male adapter and plumb it from there.