Downstreaming on high volume machines

[VanDiesel99 14]

For you guys who run high volume machines(8gpm+), do you ever have problems with downstreaming chems? I have a downstreamer that claims 20% draw, which with 8gpm would be 1.6 gals per min(20% of 8) right? I downstreamed for about 5 minutes and still have about a 2 gallons left in a five gallon bucket. Would the hose restriction be causing back pressure on the downstreamer? I know there is more pressure pushing 8 gpm through a 3/8 hose than 5gals. Thanks

[PWkid 79]

Hey Van I downstream everyday with 9.3 gpm and 8.5 gpm and 300 ft of hose on both machines the trick is you have to use a smaller oriface then what is recomended I use a 3-5 gpm downstreamer.I am not sure what ratios I am getting but it is enough to clean houses that have mold and mildew all over them.If I need more chem I slow the machine down a lil bit.

[VanDiesel99 14]

I normally xjet for house washing, but for concrete cleaning its easier for me to just pop in a soap tip and put down the degreaser. So you use a small oriface downstreamer? Do you pull it off when you are not applying soap? It seems like it would restrict overall flow leaving a smaller orifaced downstreamer on all the time.

[CCPC 26]

Hey Van I downstream everyday with 9.3 gpm and 8.5 gpm and 300 ft of hose on both machines the trick is you have to use a smaller oriface then what is recomended I use a 3-5 gpm downstreamer.I am not sure what ratios I am getting but it is enough to clean houses that have mold and mildew all over them.If I need more chem I slow the machine down a lil bit.

Ah ha!!! so that's why my adams injector has been pulling more chem. thanks

[PWkid 79]

Van I always disconnect when I'm not laying chem.It does put unwanted wear and tear on the motor and pump.

[VanDiesel99 14]

I am trying to streamline my process, but I don't want to have to stop after putting down soap and pull the downstreamer off. That adds time, plus I would have to put a ball valve behind it or shut the machine off everytime. I might as well xjet the concrete chems or get a dedicated pump and a EXTRA tank for chems. Nothing ever works like its advertised huh?

[CCPC 26]

Van I always disconnect when I'm not laying chem.It does put unwanted wear and tear on the motor and pump.

When you say that you disconnect when not laying chems, do you mean after each time you apply chem you disconnect, or do you mean, say after cleaning a whole house and before cleaning the driveway.

[PWkid 79]

First of all I have 2 machines it all depends on what surface I am cleaning.I disconnect if I am downstreaming a house and I surface clean the driveway when you put 9.3 gpm through a 3-5 gpm injector it increases head pressure and strains the motor.Most of the time I use 1 machine to downstream chems and the other to rinse or surface clean.Now when I say it strains the motor that does'nt mean it put an enormous amount of strain.I think over time over 1000 hrs or so

[Jarrod 22]

How does it strain the motor and pump? If you have an D.S. injector in your line & you are using a high pressure tip, the injector is not activated.

[VanDiesel99 14]

But there is a very small oriface in the downstreamer. This is how a ds'r works. If you use a 3-5 gpm injector it is actually undersized for the machine so the machine is straining trying to push water through a hole that isn't big enough. Thats why they make different injectors for different volume machines. What I still haven't figured out is why they even make injectors for 8gpm+ machines if your never gonna get it to draw right because of the backpressure caused by trying to push 8gpm through a 3/8 hose. Maybe I am missing something, do any of the equipment distributers have a answer?

[Russ Johnson 141]

How much hose are you using? Do you have a reel? I've never actually tested a 20% injector....just took their word for it. Might have to hook one up and see. Hose back pressure shouldn't much matter as long as it's low enough to pull the ball fully out of the seat. If it's borderline, it may "flutter" and not pull true.

[R. Williamson 14]

When downstreaming it is the pressure differential on each side of the injector that creates the draw, the greater the difference the more draw until the capacity of the draw inlet of the injector is reached.

When Mel uses a 3-5 gallon injector (2.1mm orifice) he increases the pressure on the pump side, which proportionally reduces the pressure on the discharge side of the injector increasing his draw rate, but reducing gpm to the discharge nozzle.

When downstreaming with a pump that produces more than 6 gpm with 3/8 id pressure hose this situation gets worse because of the id of the hose starts to restrict the flow. You either have to increase the inside diameter of your hose to 1/2" or do Mel's trick. When I was a contract cleaner I would plumb a Shur-flo pump into the injector pickup line to compensate, this method quickly kills injectors, but with the speed of chemical application it more than paid for the once a month injector cost.

[VanDiesel99 14]

I only use 150ft of hose but it is only 3/8in hose. Hey Bob, when you plum that shurflo in did you just turn it on and off when you were downstreaming? The machine would have to have high pressure in the line to keep the shurflo from pumping chems past the ball right? Does the shurflo pull any charge off the battery when the pressure switch kills it? What does the shurflo do to the downstreamer that damages it? Thanks!

[R. Williamson 14]

When your line psi drops the Shurflo turns on.

When the lines up to pressure the Shurflo cannot overcome the pressure and shuts off.

When the pressure switch on the Shurflo shut off it pulls no amps from the battery.

The pressure from the Shurflo weakens the spring that holds the ball off the inlet hole of the injector causing the spring to collapse.

[VanDiesel99 14]

Thats a good idea, how do you get the shurflo to prime when its connected to the downstreamer? Just turn it on, then let it run until you run the system with low pressure tip allowing the shurflo to push chems through the downstreamer?

I guess the only other option is to use 1/2 id pressure hose on the main line(2 gun system). I couldn't find a price on any 1/2in id hose. My pressure reel is already built for 1/2" connections so I am alright there. I would rather solve the problem without having to buy hose but either way its gonna run about $150 to aid the problem.