Converting 2 4gpm units to one 8gpm unit

[ryanwiles 14]

I currently have two 4gpm units 3500 psi. I am wonder if there is a way I can configure them to work in unison so that I have an 8gpm machine. Have any of you gurus out there done this? I could use any and all help

[Anthony G 14]

Ryan,

I have not done this as of yet. I just purchased a second used 3500/4gpm unit and was looking at doing the same thing. I have talked to an engineer at my full time job and we came up with this.

Set both machines at the same pressure output then have them going into a manifold with check valves on both sides then out to the hose reel (or hose). Just have to remember to use a nozzle on the gun that is suited for the 3500/8gpm when you use both pumps.

Anthony

[Doug T 19]

I believe both unloaders must be of the trapping type then you just "T" the two togather. Delco has a hose assembly that does this, they call it a "booster". Talk to Larry he will help you

[Mathew Johnson 123]

I currently have two 4gpm units 3500 psi. I am wonder if there is a way I can configure them to work in unison so that I have an 8gpm machine. Have any of you gurus out there done this? I could use any and all help

Are they direct drive or belt/gear drive? Most hose hookups that I have come across will not supply 8 gpm

You will need a float tank for 8 GPM and direct drive machines dont draft the best from float tanks

[Anthony G 14]

Matthew,

I dont know about Ryan's setup......but I have two 325 gal tanks equalized that I can add another 2" to 3/4" fitting and have these tanks supply both pumps. When the tanks get low on a job with no water supply then I just crank the trailer jack up and push the water to the back. You are correct that they dont pull very well.

Anthony

[plainpainter 217]

If you some how rig the two machines together into one output - I think there is a real danger of the pressure of one combatting the pressure of the other - I hardly doubt you will get additive pressure. You could think of it in terms of electrical circuits - where two sources of EMF - are added in parallel - it may turn out to be something like 5.6 gpm from 2 4.0 gpm machines - not a single 8.0 gpm machine. For that you would have to add them in series - and the way these pumps work - putting the output of one machine into the inlet of another isn't going to do what you want - unlike two batteries added in series.

[plainpainter 217]

Follow the KISS principle - sell the two 4.0 machines and buy an 8.0 gpm machine.

[Integrity Curb Appeal 64]

This guy talks about doing this on his website. www.waterresearchusa.com

He has seemed to make it work.

Scott

[PLD 14]

If you some how rig the two machines together into one output - I think there is a real danger of the pressure of one combatting the pressure of the other - I hardly doubt you will get additive pressure. You could think of it in terms of electrical circuits - where two sources of EMF - are added in parallel - it may turn out to be something like 5.6 gpm from 2 4.0 gpm machines - not a single 8.0 gpm machine.

You're thinking in terms of AC. Think DC. The pressures will be the average of the two, and the flow the sum of the two. Provided the hose is sized appropriately for 8gpm, the flow will be 8gpm.

[PLD 14]

I believe both unloaders must be of the trapping type then you just "T" the two togather. Delco has a hose assembly that does this, they call it a "booster". Talk to Larry he will help you

Correct. No need for a fancy hose with check valves and all that for trapped pressure unloaders (they are check valves by design). I use a $1.29 3/8" galvanized "T" from Home Depot to mate a 4.0 and a 5.5. Kicks like a mule with a #10 tip.

IMHO, there are about a dozen good reasons to mate two pumps for increased volume.

[Anthony G 14]

Phillip,

I have a small 3500/4gpm that I bought from Northern Tool years ago and I just picked up an identical unit for little of nothing. Do these normally have the trapping unloaders....they do have the pressure burst on them when you pull the trigger. I like the k7 style unloaders alot better but if these two will work together like they are then I will do the T from Home Depot.

Thanks.

Anthony

[PLD 14]

Phillip,

I have a small 3500/4gpm that I bought from Northern Tool years ago and I just picked up an identical unit for little of nothing. Do these normally have the trapping unloaders....they do have the pressure burst on them when you pull the trigger. I like the k7 style unloaders alot better but if these two will work together like they are then I will do the T from Home Depot.

Thanks.

Anthony

I don't know of ANYTHING northern sells that has a flow type unloader. The blast when you pop the trigger is the big clue that you have a trapped pressure unloader.

I know the unit you have well. 13hp belt drive, right? If so, I have one myself. Get a T, a few quick couplers, and enjoy more power. Do remember that you will need to retip everything to run at 8gpm. Otherwise, you are just wasting gasoline and giving your unloaders a workout.

Oh, and don't one hand it anymore until you are used to the new feel....

[doublejager2000 14]

plainpainter KISS method is always the best.

[Anthony G 14]

Phillip,

Thanks for the input. I appreciate the knowledge. I had thought that all northern stuff was trapped style unloaders.

A friend of my wifes wanted me to drive about an hour each way to clean a large indoor/outdoor dog kennel that she just built. She didnt even want to have to pay for the fuel cost. She then went to Northern and bought a small pw unit (2500/2.5) so that she would have it when she needed it.......called in sick on monday due to all of her muscles hurting.....some people dont realize the workout we get holding that kind of pressure.

Anthony

[Grime Dawg 14]

I use a $1.29 3/8" galvanized "T" from Home Depot to mate a 4.0 and a 5.5. Kicks like a mule with a #10 tip.

Phillip,

You may want to verify the pressure rating on that galv. 'T'.

I believe most that you find in H.D. or hardware stores are considered class 150 fittings with a maximum pressure of 300 psi. And even higher class 300 fittings are rated at just 600 psi.

That fitting could explode at any time.

-Todd-

[PLD 14]

Great point, but I got a real chuckle from this:

"(2500/2.5) ..... holding that kind of pressure"

[PLD 14]

You may want to verify the pressure rating on that galv. 'T'.

I believe most that you find in H.D. or hardware stores are considered class 150 fittings with a maximum pressure of 300 psi. And even higher class 300 fittings are rated at just 600 psi.

That fitting could explode at any time.

That is a very valid point. I recommend that everyone buy and use properly rated fittings. As for me, I've since had several HP fittings fail but never a galv iron fitting.

[Anthony G 14]

Phillip,

That friend of my wife's acted like that little unit bout killed her. Took Monday off and griped all day Tues about being sore. I had a good laugh at her expense also.

I am relocating the old unit on the trailer to make room for the new one and will set them up to run independently or together. Thanks for your input.