buffer tank

[KGILL 14]

I have recently run into water supply issues and I am thinking about getting a buffer tank. I am pushing 5.6 GPM, do you think a 35 gallon tank would suffice?

[Doug Black 18]

Buffer tanks helps your power washing immensely. I use a 30 gallon with a 5 GPM. It's awesome except for very rare super low output. As in..."I'm not quite sure how you even shower with this type of water output" Answer: "Yes, it's very hard. We were going to get that fixed" (Yes this has really happened). Sometimes on driveways you have to wait a minute but by then it's good to take a break anyway.

[apsurfacesolutions 17]

I would go with a 65 gal tank. I tried a 35 and after a couple days I switched to a 65. We use a 5.5 gal machine.

[Douglas Hicks 128]

The gallon buffer tank that came with my 3,000 psi 5 gpm just was not enough. I went with a 55 gallon barrell. I am now using a 25 gallon tank, works good for hoods.

[plainpainter 217]

I have a 5.5 gpm machine and the 35 gallon buffer works just fine. If you need any bigger than that, than you need to charge clients extra for water delivery - because there are real supply issues at

that point! My only issue is that the traditional float valves that looks like it came out the back of a toilet - allowed me to have water fill right to the top, yet it couldn't hold back any serious muni-supply pressure and the tank would leak from overfilling. The Hudson valve that replaced it, can take the pressure - but you lose like 10 gallons of capacity - and I hate that!

[apsurfacesolutions 17]

I have a 5.5 gpm machine and the 35 gallon buffer works just fine. If you need any bigger than that, than you need to charge clients extra for water delivery - because there are real supply issues at

that point! My only issue is that the traditional float valves that looks like it came out the back of a toilet - allowed me to have water fill right to the top, yet it couldn't hold back any serious muni-supply pressure and the tank would leak from overfilling. The Hudson valve that replaced it, can take the pressure - but you lose like 10 gallons of capacity - and I hate that!

And that's why I use a 65 gal tank. Figure 10 gals less in The tank and another 5 that is in the bottom. I don't haul water I fill my 65 onsite. I never run out once we start washing.

[Christopher 102]

Something to think about is the bulkhead fitting on the bottom of the tank will reduce your water by 5 to 10 gallons as this is made to keep dirt and other trash from getting out of the tank and into your pump.

A 50 gallon or larger buffer tank will be ok unless you are running 8gpm or more, then I would go with 100 gallons because a low flow situation will keep you watching your tank so you don't keep on cavitating your pump.

I would use a float valve like the hudson valve as they hold up great, just have to clean out the trash in the mesh screen once in a while and sometimes trash gets into the float itself and will not close and stop the water but that does not take long to clean out.

The guys are right, with the hudson valve you will lose 5 to 10 gallons of water area because it hangs from the top down inside the tank but I would use that float over the other brands out there.

[bks0005 14]

Whats the smallest tank you guys would recommend for a 9 gpm machine? Doing several 1 hour or so jobs per night and dont want to care more water than needed.

[Christopher 102]

That is a hard question to answer because some places might have a good flow like 10 gpm and you can get by with a 50 or 100 gallon buffer tank but some places could be like 4 or 7 gpm so you will have to shut down.

Driving around and timing the flow into buckets would be time consuming and look very odd to people, this is how you would know how much flow is coming out of the water spigots.

I would not have any buffer tank smaller than 100 gallons for 9gpm or 8gpm based on many different factors on supply and not many places have above-average flow.

100 gallons of water is 833 pounds and running 9gpm you are running out of water in about 8 or 9 minutes because of the bulkhead above the bottom of the tank if you are hauling water to each job. I would not haul water to each job running 9gpm, it will not last long, not long enough to wet everything down but if you are using it for a buffer tank you might be ok.

I would go there with the tank 1/2 full so you can get started right away once the water hose is connected and flowing into the tank. This way you are not hauling a full tank of water but a 1/2 tank will have a lot of slosh (moving back and forth) but that is up to you on how much you want to haul. Even with a 325 gallon tank, this will only last about 30 minutes or so without water going into the tank if you are only using what you hauled.

[Timo 25]

Using an 8gpm, we show up with 300 gallons on board and even with low flow faucets, we can get a lot done before we run out of water.

[bks0005 14]

So I really need either 225 being double feed or a 525 single feed to make it all work?

[plainpainter 217]

I just washed my own house the other day, took down some notes based upon it. Let's say you do a house that requires 500 gallons of total solution/rinse, and you have 5 gallon muni supply. You will need approximately 130 gallon tank for a 9 gpm machine. And that assumes you come to the job with the tank filled. As far as I am concerned large buffer tanks are for starting a job immediately, if you have to wait for it to fill - you kill the whole purpose of it especially when you are trying to combat low flowing muni supplies. Let's say you are doing two homes that require 500 gallons of solution, which is what I am estimating a 3600-4000 SF home would need, then you need to double the buffer tank to a 260 gallon tank. If you plan on three homes of that size, then you need a 400 gallon tank. After each job the tank will be approximately filled a 1/3rd less, if you get the 400 gallon tank and do 3 homes of this size. This assumes no waiting around for the tank to refill

[Christopher 102]

So I really need either 225 being double feed or a 525 single feed to make it all work?

You can make it with a 100 gallon tank if you have good flow but you will not know what you can do unless you can estimate or measure out the flow at the locations.

Having a 225 tank or even a 100 gallon tank will work if you have 2 water supply hoses feeding it if....they have low flow. If the flow is at least 8 or 9 gpm, one supply hose will keep you going but you need to know the flow.

I have had a 5gpm, 5.5gpm and 8gpm running off my 325 gallon tank but had 2, 3 or 4 supply hoses supplying water to the tank so we would not run out and have 4 hudson valves inside the tank so we don't over flow the tank, just depends on the flow.

Not every location has the same flow as another location as there are a lot of variables like size of pipe in their walls, how far they are from the municipal water tank, what time of day, how old and corroded the pipes are, etc.... that will affect the flow. I have done 2 commercial places that were not 1 year old yet but I had to run 2 hoses to supply the 5.5gpm machine where the other location would supply both the 5.5gpm and the 8gpm machine off 1 supply hose so you just never know.

If you have to haul water to any of the locations (if they do not have any water at all), you will not be able to haul enough water legally on the truck or trailer unless you can put a 1000 gallon tank on there and find somewhere to fill up for each location before getting to each location.

A couple years ago I was bidding a chain of dollar-type stores that 1/2 of them did not have any water and my 325 gallon tank would not last long at each job so I would have to haul water and pay a close-by location to use their water but a few did not have any places close by so I would have to work until I ran out of water then shut down, roll up hoses then go fill up somewhere then go back and work until I ran out of water and repeat until that job was finished.

Are you having to haul all the water to do the jobs?

[bks0005 14]

I do not have to haul water to the jobs but I have several sidewalk jobs per night on my routes. You are right water supply varies greatly from one location to the next. Most have between one and 3 water hook ups. I know I will have to double feed my tank as I currently have a 6gpm and soon a 9 gpm machine on the trailer. I will rarely use both machines at the same time but it is possible on a few locations. Should I go ahead on triple feed my 225 tank currently in the trailer. ( The 9 is a new machine being added soon).

[Douglas Hicks 128]

An easy way to determine the water flow is the bucket test. Take a 5 gallon bucket and put it under a hose bib, open the SPIGOT (not the spikket, spegot, or other mis-spellings) and note the time to fill the 5 gallon bucket. That will give you a rough estimate of the time to fill your water container. Then deduct the flow per minute your PW puts out.

Instead of using several garden hose connections and float valves on your tank, why not make up a maniflold of 2" plastic pipe and hose connections to fill the water tank? What is the difference in flow between 5/8 and 1" hose?

[happysmobile 14]

flow/ minute gpm hose id

1/2 5/8 3/4 1"

6.6 100lbs 35 14 0

10.10 200 70 25 0

These are lbs of pressure drop from a 100' hose that has 104 degree f hyd oil. Its gonna be more than if water was used in this but still quite a pressure drop. 5/8 or 3/4 most likely is gonna have no pressure drop with 100' and water when connected to a hose bib.