Peak Flow - Draining a sink

[PEDARRIN2]

I need to calculate the maximum flow rate achieved in emptying a sink. This is to estimate the peak flow to a grease interceptor. I thought about posting on the plumbing forum, but I seem to get better results here.

I know how to calculate the time it takes to drain a sink. I just assume it is a tank and use the height, area of the sink, area of the drain (assuming 2" drain), orifice coefficient (assuming 0.61), etc.

It will happen fairly early in the drainage. It will start at 0, increase to the maxium fairly quickly, then fall back to 0 as the sink empties.

Anybody know of a simple equation that can get me in the ballpark?

 

[BigInch]

You're tank drain method is likely to be as accurate, if not more so, as any other.

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"The problem isn't working out the equation,
its finding the answer to the real question." BigInch

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