1. What is the Pressure Washer Orifice Size Formula?

The pressure washer orifice size formula calculates the optimal nozzle diameter based on water flow rate (GPM) and pressure (PSI). Proper sizing ensures efficient cleaning performance and protects your pressure washer pump.

2. How Does the Calculator Work?

The calculator uses the orifice size equation:

Where:

• \( GPM \) — Gallons per minute (flow rate)
• \( PSI \) — Pounds per square inch (pressure)
• 4000 — Constant factor for standard conditions

Explanation: The equation balances flow rate and pressure to determine the ideal orifice diameter that maintains proper pressure washer performance.

3. Importance of Proper Nozzle Sizing

Details: Correct nozzle sizing prevents pump damage, maintains optimal pressure, ensures efficient water usage, and provides the right cleaning power for the job.

4. Using the Calculator

Tips: Enter your pressure washer's GPM and PSI ratings (found in the manual or on the machine). Both values must be greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What happens if I use the wrong size nozzle?
A: Too small - increases pressure risking pump damage. Too large - reduces pressure and cleaning effectiveness.

Q2: How precise does the orifice size need to be?
A: Very precise - even 0.001" differences can significantly affect performance. Use manufacturer-recommended sizes when available.

Q3: Does water temperature affect the calculation?
A: This calculation assumes standard cold water conditions. Hot water pressure washers may require adjustments.

Q4: Can I use this for different spray angles?
A: This calculates for 0° (straight stream) nozzles. Different angles require adjustments to the flow rate.

Q5: What about metric measurements?
A: Convert to GPM (1 GPM = 3.785 LPM) and PSI (1 PSI = 0.0689 bar) before using this calculator.