Hydraulics
Pipe size guide
Pipe size is the inverse of flow: if you know the target flow and an acceptable velocity, you can estimate a useful diameter. This guide shows the basic logic before you open the calculator.
How it works
Diameter comes from flow and velocity
Core relationship
Area = flow / velocity
Diameter = 2 × sqrt(area / pi)
Practical note
The final pipe choice still depends on pressure loss, fittings, elevation, and the acceptable velocity for the system.
When to use it
Good for rough sizing decisions
Branch sizing
Choose a diameter for a known branch flow before you commit to a size.
Quick comparison
Compare the effect of a higher or lower velocity target on diameter.
Planning stage
Useful before detailed hydraulic design or supplier selection.
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