How To Choose A Pressure Washer Tank?

How To Choose A Pressure Washer Tank?

It takes a lot of work and time to choose a suitable pressure washer tank. The exam is especially important when buying a pressure washer tank. We will guide you on how to get a pressure washer tank.

Tips On Buying And Using A Pressure Washer Tank

  • Always check the tank’s ability to supply the number of gallons per minute specified for your pressure washer before purchasing a pressure washer tank for it.
  • In order to use a pressure washer tank with your pressure washer, first install a pressure washer filter. Because of the dirty water coming from the tank, your machine may clog or become damaged.
  • In most cases, if the pressure is insufficient, you will require an additional pump between the tank and the pressure washer. You can use a regular water pump to raise the water pressure if you can see that it isn’t high enough.

General Rule Of Thumb For Sizing A Pressure Washer Tank

Generally, as a rule of thumb, one can follow these guidelines when sizing a pressure washer tank:

  1. 0-10 GPM: 1 gallon of drawdown per 1 GPM of flow
  2. 10-20 GPM: 1.5 gallons of drawdown per 1 GPM of flow
  3. 20 GPM+: 2 gallons of drawdown per 1 GPM of flow

Drawdown can be defined as the amount of volume loss in the pressure washer tank as the plumbing system “draws” off this pent-up pressure. After all, a pressure tank’s main function is to keep the pressure in a particular system constant while the pump is resting. In this manner, system pressure can be maintained without the pump running continuously. A pressure tank may initially seem expensive, but it will end up saving money. The pump will require less maintenance and energy, which will save money.

The most popular pressure tank orientations are horizontal, inline, and vertical, though there are other options as well. Make sure to ascertain which orientation is ideal for your plumbing configuration.

When we know our flow rate in gallons per minute (GPM), our cut-in/cut-out pressure, and our target run time, we must choose what cut-in/cut-out pressure we want to set the system at.

Pressure Washer Tank Sizing Explained

An important equation to remember when sizing a pressure washer tank is below:

Flow Rate X Run Time = Tank Draw Down Capacity


Consider a motor that drives a 5 GPM pump that has a ¾ HP capacity. Since I’m operating a motor that is less than 1 HP, we are going to assume that “ABC Manufacturer” recommends a 1-minute runtime. This system will be built to cut in (turn on) at 40 psi and cut out (turn off) at 60 psi.

5 (Flowrate) X 1 (Runtime) = 5 gallons of Draw Down (at 40/60PSI)

I must choose a tank that permits a 5-gallon drawdown at a pressure setting of 40 PSI cut-in and 60 PSI cut-out. If I need a vertical tank, I could select a WOMAX-220. If my plumbing layout would accommodate a horizontal tank better, I could select a WOMAXH-220. 3.5 minutes would pass before the pump turned back on as a result of this. For maximum space efficiency when designing a plumbing system, horizontal pressure tanks have a plastic pump stand. When working in small, constrained spaces, this feature is undoubtedly useful.

The Need Of Gallons For Power Washing A House

Depending on the tasks you’ll be performing with the pressure washer tank and how long you plan to use it, the water tank’s capacity will vary.

Your water tank should be bigger to ensure that it won’t run out while you’re working for a longer period.

Power washing a house usually takes between 30 and two hours. Smaller homes with an approximate 1,300 square foot size can typically be finished in 30 minutes.

If your cleaning task takes two hours or more, a 250-gallon water tank won’t be sufficient. To ensure you have enough water, choose a tank with a capacity greater than 250 gallons if your cleaning task will take longer than two hours.

PSI (pounds per square inch) and GPM (gallons per minute) are important factors to consider when choosing a pressure washer. A medium-duty commercial pressure washer will have a PSI of 2,600 to 3,100 and use 2.5 gallons of water per minute.

Make sure there are roughly 75 gallons of water in the tank if you plan to use this machine for 30 minutes. On the other hand, a commercial heavy-duty pressure washer will have between 3,200 and 4,000 PSI and use three to four gallons per minute.

If it uses four gallons per minute and you’re using it for 30 minutes, you’ll need 120 gallons of water in the tank.

You should use this example to determine the ideal size of your pressure washer tank.

pressure washer tank

Relationship Between Pressure And Tank Size

It’s crucial to keep in mind that the size of the tank must increase with the operating pressure. A direct relationship exists between pressure and tank size; as one rises, the other follows. Less drawdown occurs at higher pressure settings, necessitating larger tank capacities.

After establishing these three criteria, we can move on to sizing a pressure tank. Any plumbing system should take into account the pressure settings as well. The pressure ranges 30/50, 40/60, and 50/70 are the most popular ones. Most manufacturers will have a pressure tank sizing chart that will enable users to quickly size a tank’s drawdown based on their system’s pressure settings.

If you’d like more information on the Wilo MaxAir® product line, we can give it to you. Contact us at any time by dialing or going to Here is a drawing of a Wilo MaxAir horizontal tank that details some features that distinguish this product line from the competition and truly place it among the top offerings on the market.

Guide To Connect A Water Tank To A Pressure Washer

  1. First, make sure the water tank has a banjo fitting before attaching it to the pressure washer.
  2. Before using Teflon tape to secure it, connect a threaded pipe to the fitting and then connect an inline to the PVC.
  3. Then, connect your hose to it after connecting the ball valve and barb connector. To prevent water leakage from the hose, the barb connector must be tightly clamped.
  4. Your pressure washer’s feed line and the hose should be connected.

Now, do you grasp the method of how to choose a pressure washer tank and using it?

Related Questions

Why Are You Not Getting Enough Pressure?

If your pressure washer is connected to a water tank but you’re still not getting the pressure you require, you should check a few things.

Check the hose connections first, and then make sure the water faucet in the tank is turned on. After that, make sure the spray wand is not in the low-pressure or no-pressure mode. If it has, adjusts it.

Can Your Pressure Washer Use Water from a Lake?

Although it might seem like a good idea, this rarely works. You’ll need a pressure washer that works with a suction hose if you want to give it a try. You will need a filter though because the water contains impurities.

Can You Connect a Pressure Washer to a Rain Barrel?

If your rain barrel has a bottom outlet, you can attach a hose or suction hose to it so you can use it with a small pressure washer. But for the pressure washer, the pressure must be high enough.