formula.expertYour record

Closed Loop Slug Dose Volume

Also known as slug dose · one-shot dose

Vp=C Vs ρwρpV_p = \frac{C \, V_s \, \rho_w}{\rho_p}
sig figs

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.

Enter your known values, leave one input blank, and solves for the missing one. Tap a variable’s symbol to see what it means, with a typical value. Change any unit and the answer follows.

Where Closed Loop Slug Dose Volume fits

Missing an input?
In this toolkit

See also

Dose Achieved from Chemical Added: Both use system volume and target concentration.Chemical Feed Rate (lb/day = mg/L × MGD × 8.34): Both use target concentration.Chemical Feed Rate from Dose: Both use target concentration.Corrosion Rate from Coupon Weight Loss: Both use product density.Glycol Dilution: Both use system volume.Holding Time Index: Both use system volume.
4 more relatedProduct Dose from Active Strength: Both use target concentration.System Volume from Turnover Time: Both use system volume.Alkalinity Remaining After Alum: Both use target concentration.Jar Test Dose Scale-Up: Both use target concentration.
Here the solver did the work. Could you?

Dosing the loop →

UniversityProcess & Water Chemistry

Test your skills in the Exam Room: new numbers every attempt. Free lessons for students, no sign-up, just pure learning.

See your Report Card
Learning zone

Closed Loop Slug Dose Volume explained

VsCVpρp

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

Vp=C Vs ρwρpV_p = \frac{C \, V_s \, \rho_w}{\rho_p}
Where
  • VpV_p= Product volume to add (L)
  • VsV_s= System volume (L)
  • CC= Target concentration (mg/L)
  • ρp\rho_p= Product density (kg/m³)
Where this comes from

Worked from first principles: a definition, a balance or unit arithmetic, so it needs no outside source.

In this toolkit

Chemical dosing and feed rates

7 formulasFeed rate, dose from mass added, slug dose and product strength — converting between ppm, pounds per day and gallons of product.

Revised 30 October 2026
Cite this page

formula.expert. (2026, October 30). Closed Loop Slug Dose Volume Formula & Calculator. https://formula.expert/solvers/closed-loop-slug-dose

formula.experthttps://formula.expert/solvers/closed-loop-slug-dose