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GPM to FPS Formula:
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The GPM (gallons per minute) to FPS (feet per second) conversion calculates the velocity of fluid flow in a pipe. This is important for determining flow characteristics, pressure drops, and ensuring proper system design in plumbing and hydraulic systems.
The calculator uses the conversion formula:
Where:
Explanation: The formula converts volumetric flow rate (GPM) to linear velocity (FPS) by accounting for the cross-sectional area of the pipe.
Details: Proper flow velocity is crucial for efficient system design. Too high velocity can cause erosion, noise, and excessive pressure drops, while too low velocity can lead to sedimentation and poor system performance.
Tips: Enter flow rate in GPM and pipe diameter in inches. Both values must be positive numbers. The calculator will provide the velocity in feet per second.
Q1: Why is the conversion constant 0.408?
A: The constant 0.408 comes from unit conversions: 1 gallon = 231 cubic inches, 1 foot = 12 inches, and 1 minute = 60 seconds.
Q2: What is a typical flow velocity in plumbing systems?
A: For water systems, typical velocities range from 2-8 fps for cold water and 2-5 fps for hot water to minimize noise and pressure drop.
Q3: Does this formula work for all fluids?
A: The formula is specifically for water at standard conditions. For other fluids, additional factors like density and viscosity need to be considered.
Q4: How does pipe material affect flow velocity?
A: Pipe material affects the friction factor and roughness, which influences pressure drop but doesn't change the basic velocity calculation from flow rate and diameter.
Q5: When should I be concerned about flow velocity?
A: Be concerned when velocities exceed 8-10 fps in copper systems or 5-7 fps in plastic systems, as this can cause erosion, water hammer, or excessive noise.