Closed Loop Slug Dose Volume
Also known as slug dose · one-shot dose
Worked example: 200 ppm into 1000 gal with 9.5 lb/gal product → 0.6646 L — press Try an example to run it live, then adjust anything.
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UniversityProcess & Water Chemistry
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Closed Loop Slug Dose Volume explained
Closed loops are not fed continuously — they get slugged. You want a target ppm in the loop, you know roughly how many gallons the loop holds, and the drum in your hand is a liquid whose label gives a density in pounds per gallon. Convert the required mass of product to a volume you can actually pour: 200 ppm into 1000 gallons needs 200 × 0.001 × 8.34 = 1.67 lb of product, and at 9.5 lb/gal that is 0.176 gal — about 22.5 fluid ounces. Measure it in a graduated pitcher, not by eye.
Chemical density is the part people skip. Nitrite and molybdate inhibitors commonly run 9.5–10.5 lb/gal, glycol-based products near 8.6, and concentrated caustic 12.7 — assuming water density can put you 25% off. Field practice: pour the slug into a bypass feeder (a pot feeder), open the isolation valves, and give the loop at least three full turnovers before you test. Testing ten minutes after dosing produces a beautifully wrong result and a second unnecessary slug on top of it.
Closed Loop Slug Dose Volume formula
- = Product volume to add (L)
- = System volume (L)
- = Target concentration (%)
- = Product density (kg/m³)
Missing one of these? Work it out first, then come back
- Product volume to add — Density, Molarity (C = n/V)
- System volume — Dose Achieved from Chemical Added, Holding Time Index
- Target concentration — Glycol Dilution, BOD Mass Loading
- Product density — Corrosion Rate from Coupon Weight Loss, Fourier Number