Bypass hose from unloader to buffer tank

I searched the forum for this specific info with no luck, but this is probably a pretty simple question. When bypassing from the unloader back to the buffer tank, is normal, crushproof polybraid hose sufficient or is a higher pressure hose necessary?

Also, somewhat related question: can the supply inlet put out enough pressure to cause air bubbles which could cavitate the pump? I want to put my 1" bulkhead in the bottom-middle area of the tank so it can go directly to my pump without any turns but was somewhat concerned about possible air bubbles caused from my supply. The bypass will be no issue as I’ll divert it with an elbow inside the tank.


Polybraid is fine. No cavitation issues. Don’t be afraid of some bends. I use 1 inch crush proof suction hose for my feeds


Thanks a lot, @Innocentbystander. I didn’t think it would be an issue but figured I would check first. Appreciate it!


If you’re worried about bubbles, install a second 90° elbow on the inside of the bulkhead. That way you can direct the flow against the side of the tank.


Thanks, Alex. That’s an option to consider as well!

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I’ve run into a few houses that didn’t have enough water at the spigot to feed my 4 GPM machine. I think I want to set up a buffer tank, but I have a lot of dumb questions and I don’t want to break anything. What is the yellow washer for? What holds the hose onto the threaded part? Can I unscrew the whole thing or is it welded in there? Should I unscrew the bypass hose and replace it with a barb fitting and a plug? Does it need a hose clamp or something?

The side with the small rubber hose leave alone it is going to a pressure valve as a back up if your unloader fails. the other side should have a plug in it, which you would take out and hook your male 1/2 hose barb to. At least I think but I can’t really see it on the small phone screen… But if not you would remove the one end of the hose going to the relief valve and attach it to the other side of the high pressure side of the pump.

No offense, but don’t do that. Pull of hose from water intake. Replace with hose barb to feed from tank. Run hose from unloader to tank. Hose just pushes onto yellow fitting like a plumbing shark bite. No clamp needed. Don’t plug or unplug anything on unloader. Just extend preexisting hose to buffer tank

No offense, I was answering the question “What is the yellow washer for? What holds the hose onto the threaded part? Can I unscrew the whole thing or is it welded in there? Should I unscrew the bypass hose and replace it with a barb fitting and a plug? Does it need a hose clamp or something?” there are several ways to hook up the bypass hose… it depends on which type of unloader he has.

My bad

ok, my understanding of these unloader buffer tanks: hose goes from unloader to a tank, at the top. The hose goes from bottom of said tank back to unloader. Thus allowing for a great flow of water into the pump. Kind of boosting the gpm Into. Plus the benefit of being able to let go of gun for more lengthy periods of time without damaging the pump? Am I correct?

No, the hose from the bottom of the tank goes to the pump inlet, not back to the unloader.

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Alright, so it will assist in increasing gpm flow into the pump, allowing for a higher gpm PW? Sorry if I sound dumb, just jumped into learning about unloaders/bypass tanks tonight.

No, it doesn’t increase gpm. Maybe you needed more than one night of research :slight_smile:

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Haha, I have it. Researching leads to questions, which leads to asking. Thus here I am.

So the buffer tank flow back into the pump inlet but doesn’t affect the gpm flow?

Don’t lose too much sleep over the inner workings of an unloader, there simple Set and forget things that will make sense when the time comes for a buffer tank. That other turkey on the other thread that bolted 2 unloaders together probably didn’t help your research lol.

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There are two main reasons for a buffer tank. The first reason is if you go to a house where the hose spigot only puts out 3 gpm you’ll be able to run your pressure washer still without ruining the pump. You might have to stop washing and wait for the tank to fill back up but at least your pump is getting the amount of water in needs. The other reason is to be able to let off of the trigger and not have to worry about your pump overheating because water keeps recirculating.

To hook up a a buffer tank you run a non collapsible hose from the buffer tank to a water filter and then to your pump. You then run a bypass hose from unloader to buffer tank. When you pull up to a house you run a garden hose from the house to your buffer tank.


@cturner120 Here’s a picture from Pressure Washer Products detailing the explanation that Brian gave you.

I noticed the picture lists ”NO TEFLON TAPE” and that is inaccurate. Teflon tape is standard practice for all high pressure fittings. That site pushes blue thread lock instead of tape and a few on here say it works but I haven’t tried it.

Visit these sites if you haven’t already and look around, you’re bound to learn something about professional equipment and accessories:


@marinegrunt thanks for the breakdown @PristineGC thanks for that diagram. Both tied the questions I developed with the images I had in my head on how it was laid out. Truly, appreciate it. Once I’m prepared to add a smaller one to my truck bed, I’ll be able to now, thanks

Yeah I have Teflon tape for days, use at every HP connection thats not QC

That diagram also doesn’t have a water filter between building supply and buffer tank. Make sure you install one on the truck when you go with a buffer. The filters from PressureTek work great