Process Manufacturing worked example
Tank Empty Time at 17% heel, rinse, and delay allowance: a worked example
What does the result look like when heel, rinse, and delay allowance reaches 17%? The full calculation is worked below with real intermediate numbers. planning a tank empty, drain-down, or transfer-out step before cleaning or the next batch
The inputs for this scenario
- Volume to empty: 2,800 gal (unchanged)
- Pump-out or gravity drain rate: 70 gal / min (unchanged)
- Heel, rinse, and delay allowance: 17 % (raised for this scenario; the documented default is 15)
Working through the calculation
- Applying the documented formula (Base empty time = volume to empty รท pump-out or drain rate) to the inputs above produces each figure below.
- At this operating point the engine returns 46.8 min for required tank empty time, the number this scenario is built around.
- At this operating point the engine returns 40 min for base tank empty time.
- At this operating point the engine returns 17 % for emptying allowance applied.
- At this operating point the engine returns 70 pieces / min for pump-out or drain rate.
How this compares with the baseline
- Against the tool's baseline example, where heel, rinse, and delay allowance sits at 15% and the headline result is 46 min, this scenario comes in 1.74% above the baseline at 46.8 min.
- A figure at this level is achievable when heel, rinse, and delay allowance is genuinely sustained, not just peaked for a shift. It uses one average rate, but real drain rate falls sharply as head decreases, and the final heel can take disproportionately long; treat it as a planning estimate.
Results at a glance
- required tank empty time: 46.8 min (headline result)
- base tank empty time: 40 min
- emptying allowance applied: 17 %
- pump-out or drain rate: 70 pieces / min
Run it with your numbers
- Every input above is editable in the live Tank Empty Time calculator, which recalculates instantly and can be shared with the inputs intact.
Last reviewed 2026-05-12.