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Cleaning Chemical Calculator
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Pressure Washer Injector Draw Calculator

Chemical drawn through a downstream injector over a wash, in gallons and fluid ounces, with what that chemical costs.

Inputs

Range: 0.1–20 galmin

From the machine plate. A 4 gallon per minute machine at 3,000 psi is a common specification.

Range: 1–200

Read it from the injector metering tip. 10:1 and 20:1 tips are both common and differ by a factor of two on the chemical bill.

Range: 1–600

Enter the measured or label value in the units shown.

Range: 0–1,000,000 per gallon

Enter the current purchase price in US dollars for the unit shown.

Result

Chemical drawn in fl oz
1,536.0 fl oz
Chemical drawn
12.000 gal
Chemical cost of the wash
$240.00
Chemical cost per minute of washing
$8.00
Solution sprayed
120.0 gal
Reading: what this result means for the job
More than five gallons of chemical for one wash. At this draw the injector ratio and the metering tip are the whole cost, and a tip one size too rich adds a pail to every pass.
Applicability limit
The draw follows the machine flow rate, the injector ratio and the wash time entered, and the ratio is the figure that is usually wrong: a downstream injector falls back and dilutes further as the tip wears and the pressure drops. The result is the chemical that leaves the pail, not the chemical that lands on the surface. This is a planning figure for the values entered, not a measured result. Coverage rates, product yields and application rates are properties of a specific product, applicator and substrate, and the label or data sheet for the product you are using always takes precedence over the default here. The EPA-registered label governs. Using a registered antimicrobial inconsistently with its labeling is unlawful under 7 U.S.C. 136j(a)(2)(G), and 40 CFR 156.10(i)(2)(ii) requires every label to carry that statement. This tool does arithmetic; it does not approve a dilution, and it does not determine compliance.
Check before the job

Working

Solution sprayed
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Chemical drawn
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Chemical drawn in fl oz
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Chemical cost per minute of washing
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Chemical cost of the wash
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What to check

  • Read the injector ratio from the metering tip colour chart, not from memory.
  • Check the machine flow rate on the plate rather than the sales literature.
  • Confirm the concentrate price is per gallon and the product is not a ready-to-use blend.

Related calculators

Injector draw is read from the metering tip, not assumed: a 10:1 and a 20:1 tip differ by a factor of two on the chemical bill and by nothing at all on the water bill. The result is the chemical that leaves the pail, not the chemical that lands on the surface.