Hays Velocity Calculator   Inputs Diameter, D: inches Flow Rate, Q: GPM (US) Calculations Velocity, V: ft/sec   Additional Useful Tools: Min Diameter (based on Vmax = 7fps) Enter GPM (US): Min. Diameter: inches Pipe Size (recommended):   Qmax through a pipe Enter Diameter, D: inches Enter Velocity, Vmax: ft/sec Max. Flow: GPM(US)