Technical Tools

Velocity Calculator

To determine velocity, divide flow rate by cross-sectional area. This simple equation applies only to flowing liquid, not gas, due to the fact that liquid cannot be compressed and therefore density and volume remain the same. On the other hand, changes in gas pressure and temperature affect those inputs, and a more complex calculation is needed to determine velocity when flow media is gas.

As a general rule, velocity in corrugated metal hose should never exceed 150 ft/sec for gas or 75 ft/sec for liquids otherwise resonant vibration can occur which can cause very rapid failure of the assembly. Where velocity exceeds these rates, an interlocked metal hose liner or larger hose I.D. is recommended. Contact us for design recommendations.

Note on Using Calculator

This calculator is designed to determine the velocity of liquid flowing through Penflex hoses. Flow rate needs to be in cubic feet per minute (ft3/min) for calculator to work properly. If flow rate is known in gallons per minute (gal/min), input flow rate and click “Convert” before hitting “Calculate.”