Pressure Washer API

Pressure-washer maths as an API, computed locally and deterministically — the cleaning-power, nozzle and water numbers a buyer or pro sizes and runs a machine by. The cleaning-units endpoint gives the cleaning power, PSI × GPM, with a duty class — both matter because pressure breaks the dirt loose and flow flushes it away, so a 3,000 PSI / 2.5 GPM machine (7,500 cleaning units) cleans far faster than the same pressure at 1.5 GPM. The nozzle endpoint gives the flow at a different pressure (a fixed nozzle flows with the square root of pressure) and the nozzle reaction force you feel, ≈ 0.0526 × GPM × √PSI in pounds — a few pounds on a consumer unit, enough on a big machine to need two hands. The water-usage endpoint gives the water used over a run, flow × time, in gallons and litres with an optional cost — a pressure washer actually uses far less water than a garden hose for the same cleaning. Everything is computed locally and deterministically, so it is instant and private. Ideal for pressure-washer shops and rental apps, cleaning-contractor and buying-guide tools, equipment calculators, and DIY sites. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 compute endpoints. Estimates — surface and detergent matter as much as the numbers.