Discharge Pipe Diameter
Calculate the inner diameter of a discharge pipe from the flow and flow velocity, D = √(4·Q ÷ (π·v)), from the flow Q (m³/s) and the desired flow velocity v (m/s). It is the direct application of the continuity equation (Q = v·A, with A = π·D²/4), solved for the diameter: given the flow to transport and the chosen operating velocity, the required pipe diameter is obtained. In hydraulic solids transport (dredging, pipelines), the diameter choice is critical and COUPLED to the critical deposition velocity: the operating velocity must stay above the critical velocity (to avoid deposition/clogging) but not excessively high (to avoid wasting pumping energy and accelerating abrasive wear). So sizing is iterative — a diameter is chosen, the resulting velocity and corresponding critical velocity are computed, and it is adjusted until a safe, economical operating range is found. Larger diameters reduce velocity and head loss (less energy per metre) but cost more and may fall below the critical velocity; smaller diameters raise velocity and wear. This simple but essential calculation is the starting point of designing any water or slurry discharge line. Enter the flow and the flow velocity.
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Discharge pipe diameter
The internal diameter of a discharge pipe follows from the flow rate and the velocity as D = √(4·Q ÷ (π·v)), built from the flow rate Q and the desired flow velocity v. It is a direct application of the continuity equation (Q = v·A, with A = π·D²/4) solved for the diameter: given the flow to be carried and the chosen operating velocity, it returns the required diameter. In the hydraulic transport of solids (dredging, slurry pipelines) the choice of diameter is critical and is coupled to the critical deposition velocity: the operating velocity has to stay above the critical velocity (so the solids do not settle and plug the line) yet not run excessively high (to avoid wasting pumping energy and accelerating abrasive wear). Sizing is therefore iterative — pick a diameter, compute the resulting velocity and the corresponding critical velocity, and adjust until the operating point falls in a safe and economical range. Larger diameters lower the velocity and the head loss (less energy per meter), but cost more and may fall below the critical velocity; smaller diameters raise the velocity and the wear. This simple but essential calculation is the starting point for the design of any water or slurry discharge line. Enter the flow rate and the flow velocity.
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