Does Pressure Washer Draft ?

[bcarwell]

I have a garden variety Sears 2500 psi pressure washer. I am considering using it out in the pasture for fire burn supression where I just have a 550 gallon tank and no household 24-40 psi water pressure to feed the washer with.

Can I just stick a garden hose from the intake of the washer into the tank or maybe at the bottom where there is at least some pressure from the full tank ? Will it damage the washer that I don't have the household pressure on the intake side ? The instruction manual for the washer says to never run it without water attached which makes sense since it will hurt the pump to run it dry. But it doesn't make it clear whether you have to have <pressurized> water on the intake or will just any old source of water do. Note the tank is level with the pressure washer and I'm not drying to draft water from a location lower than the washer..

Bob

[J_J]

I have a garden variety Sears 2500 psi pressure washer. I am considering using it out in the pasture for fire burn supression where I just have a 550 gallon tank and no household 24-40 psi water pressure to feed the washer with.

Can I just stick a garden hose from the intake of the washer into the tank or maybe at the bottom where there is at least some pressure from the full tank ? Will it damage the washer that I don't have the household pressure on the intake side ? The instruction manual for the washer says to never run it without water attached which makes sense since it will hurt the pump to run it dry. But it doesn't make it clear whether you have to have <pressurized> water on the intake or will just any old source of water do. Note the tank is level with the pressure washer and I'm not drying to draft water from a location lower than the washer..

Bob

If you have ever had someone turn the water off on you and the pressure washer quit running because of water starvation, did you notice that the supply hose was almost flat. It sucked all the water it could, and you were on your way to pump damage.

So, my opinion is, that if you have a stiff hose, and no folds, I believe you can do it. It should pull water.


The reason that you never run the pressure washer without water is because the ceramic seals in the pump need the water for lubrication and keeping the seals cool. You will notice that with pressure washer running and you not spraying, after a while, you will notice the water is rather warm. What it does is to recycle the water in a loop until you pull the trigger.

For around $225, you can get a gas driven water pump that will put out lots of water for things like fire, watering, irrigation, etc

[bcarwell]

JJ,
MANY thanks for the quick, logical and informative response. Personally I wouldn't have thought of the stiff hose precautionary thing, but at least suspected that I didn't HAVE to have 35 psi on the intake side. Never experienced the hose flattening since nobody ever turned my water off, and frankly never felt the warmth when not spraying but it makes absolute sense.
So I may just try initially with the tank/pressure washer before buying a pump. BTW, what kind of pump/where are you talking about in the $200+ range ? Harbor Fright's pumps (120 gpm+) I thought were in the $300's but maybe that's the "high pressure" pumps. Somebody told me I could get by with a trash pump and 2 inch discharge hose by using a 1 inch nozzle to get the pressure/distance I needed since I don't need as much flow as I do distance (e.g. 60 pgm and 60 psi or so should do)...
So do you have a pump in mind ?
Thanks again !

Bob

[J_J]

Here are a few from the Surplus Center.

Burden Sales Surplus Center


http://www.northerntool.com/webapp/w..._6970_107+1545

[HCJ]

Most pressure washers require a minimum flow rate and minimum pressure. My owners manual specifies this, so drawing out of a tank is not recommended. What you need is a small pump designed for this. I use a Honda 25cc 1" minipump sold at Northern for $390. It's really small, but very powerful and easy to use. My municipal parks department uses them to water remote plantings from a pickup truck tank. I have one and use it also to water plants from my truck (250 gal. tank) and also to wash my tractor from a rain collection cistern. (we don't have water at our barn) It will pump a 250 gallon tank dry in about 20 minutes and flows with the rate and pressure of a good strong garden hose. You will need a stiff suction type 1" hose at the intake side (also sold at Northern), and any garden hose and nozzle at the other output side. Works great!! It's not a pressure washer but as powerful as good normal hose. I have used it "in-line" to pump water to my pressure washer to achieve proper flow and pressure, when I needed pressure, but that's a hassle. If you must have a pressure washer, there are some made that will draw from a tank. I found one at Karcher's web site. But for remote use to put out high volume at regular pressure as you described, the little Honda pump can't be beat. You can pick it up with one hand. I keep mine in my pickup truck box. Collecting rainwater for a use like this may be something you want to consider.

[HCJ]

By the way, the Northern item # for this pump is 109424-1806

[EastTexFrank]

I would have thought that the 1" mini pump would be the way to go. I've seen 2-stroke ones for under $200.

I don't think that a power washer is a good tool for fire supression, unless as a last resort. They create too much air movement and blow stuff all over the place if your not careful. That would seem to be the last thing you'd want - you need less pressure, more volume.

[J_J]

You got to use some logic here. If the pressure washer will put out 3 GPM, then it has to draw in 3 GPM. And of course you would use a stiff large hose.

You could also use just the pump section that is attached to the 5 HP units and build you a PTO pump setup. A big pulley driving a small one might get you up to 3600 rpm . 8700 gph, that is a lot of water.

[SPYDERLK]

Pressure washers put out intense pressure and low volume. You dont want that much pressure. A hundred PSI at 5 or 10 GPM would be good. You will not get high flow like that from a pressure washer. If you ran an open nozzle yould be able to keep the pressure down but the second you valved off the pressure would go right up to the pump relief setting of 2kpsi+. Not a real controlable situation if you want a limited spray.
larry

[Reg]

In cold weather I usually leave mine running while I go to the outside faucet, which I turn it off as I unscrew the hose. Then I spray until there is no water coming out, hasn't hurt it in 6 or 7 years and I've never had ice in the pump or the 150 ft of hose.
Yes, if it works it works, but shut it off real quick if the hose collapses.