How to use Hydraulic hose sizing& flow velocity calculator
- Enter System flow rate (L/min) and adjust the options as needed.
- Run the tool and inspect its results, evidence and limitations.
- Copy or download the result, then verify it against the actual website, source data or business records.
Try a concrete example
A 60 L/min pressure line recommends Dash -08 (nominal 1/2", ~12.7mm ID) with an actual velocity of ~7.89 m/s.
How to interpret results
Uses V = 21.22 × Q / d² to match SAE J517 / ISO dash sizes. Verify bend radius and burst pressure for extreme pulsation.
Frequently asked questions
What do hose Dash sizes (-04, -06, -08, -12) mean?
Dash sizes indicate sixteenths of an inch: -04 is 1/4" (6.3mm), -06 is 3/8" (9.5mm), -08 is 1/2" (12.7mm), -12 is 3/4" (19mm), -16 is 1" (25.4mm).
Why must suction line velocity stay under 1.2 m/s?
Suction lines rely on atmospheric pressure. Excessive velocity creates vacuum drop, causing dissolved air to implode (cavitation), destroying pump elements.
What happens if pressure line velocity is too high?
High velocity causes friction pressure drop converted to intense heat, degrading seals and causing fatigue vibration.
How to determine the required hose working pressure?
Inner diameter sets velocity; reinforcement plies set working pressure. Verify SAE 100R2/100R12 or DIN standards with a 4:1 safety factor.