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Next, the maximum allowable flow rate through the valve must be calculated based on the maximum laminar flow through a reasonable length tube, the maximum head loss through the float valve (given in Design Assumputions), and available tube diameters. The allowable flow rate is based on eliminating the diameter from the Hagen-Poiseuille equation by using the maximum Reynolds number constraint. For higher flows multiple parallel tubes could be used. However the maximum flow rate that can be handled by the float valve needs to be considered.
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