| Fluid ounces per minute (fl oz/min) | Liters per minute (L/min) |
|---|---|
| 1 Fluid ounce per minute | 0.0284130625 L/min |
| 2 Fluid ounces per minute | 0.056826125 L/min |
| 3 Fluid ounces per minute | 0.0852391875 L/min |
| 4 Fluid ounces per minute | 0.11365225 L/min |
| 5 Fluid ounces per minute | 0.1420653125 L/min |
| 10 Fluid ounces per minute | 0.284130625 L/min |
| 20 Fluid ounces per minute | 0.56826125 L/min |
| 25 Fluid ounces per minute | 0.7103265625 L/min |
| 50 Fluid ounces per minute | 1.420653125 L/min |
| 100 Fluid ounces per minute | 2.84130625 L/min |
| Reference | Fluid ounces per minute (fl oz/min) | Liters per minute (L/min) |
|---|---|---|
| A domestic shower | 316.756 fl oz/min | 9 L/min |
| A kitchen tap | 351.951 fl oz/min | 10 L/min |
| A garden hose | 527.926 fl oz/min | 15 L/min |
| The Amazon river | 4.41346 × 1011 fl oz/min | 1.254 × 1010 L/min |
The fluid ounce per minute is a unit of volumetric flow rate equal to one imperial fluid ounce passing a point every minute. Its symbol is fl oz/min. At 28.413 millilitres to the ounce, a minute at this rate delivers a small glass, which places the unit among the deliberate, controlled flows of food, drink and light industry.
Beverage dispensing is its steadiest employer. A post-mix drinks tower is set so that each nozzle delivers a fixed number of fluid ounces per minute, and the ratio of syrup to carbonated water — commonly one to five — is maintained by matching the two rates. A coffee machine's brew rate, a beer line's pour rate and a juice dispenser's throughput are all quoted this way.
Small dosing and metering pumps in food processing carry the same units. Flavourings, colourings, brines and preservatives are injected into a product stream at so many fluid ounces per minute, and the ratio to the main flow is what determines the finished recipe. A pump that drifts by five per cent changes the taste of every package made that shift.
Cleaning and chemical injection follow the same pattern. A dairy or brewery cleaning system meters detergent and sanitiser into circulating water at a rate in fluid ounces per minute, chosen so that the concentration in the loop matches what the supplier specifies for the temperature and contact time being used.
Laboratory and pilot-plant work in Britain and the Commonwealth still meets the unit in older equipment and older standard methods. Rotameters graduated in fluid ounces per minute remain in service, and a technician reading one must remember whether the scale is imperial or American, since the two ounces differ by four per cent.
For orientation, 60 fluid ounces per minute is one fluid ounce per second, 35 fluid ounces per minute is about a litre per minute, and 160 fluid ounces make an imperial gallon. So a dispenser running at 32 fluid ounces per minute fills a gallon in five minutes exactly.
One fluid ounce per minute equals about 28.41 millilitres per minute, about 0.02841 litres per minute, or about 0.01667 fluid ounces per second.
The litre per minute is a unit of volumetric flow rate equal to one litre passing a point every minute. Its symbol is L/min. It is the unit of taps, showers and small pumps — the flows a person meets directly, at a rate slow enough that a minute is the natural interval to count over.
Household plumbing is specified in it almost everywhere. A modern shower head delivers 6 to 9 litres per minute, an older one 15 or more, a kitchen tap 5 to 10, and a bath filler 15 to 20. Water-efficiency regulations in many countries set maximum figures in exactly these terms, because the flow rate multiplied by a typical shower length gives the volume of water and the energy needed to heat it.
That calculation is the reason the unit matters beyond plumbing. Reducing a shower from 12 to 8 litres per minute cuts both the water and the heating energy by a third, and heating water is one of the largest energy uses in a house. A restrictor costing very little changes a household's energy bill measurably.
Medicine uses the unit for gases. Oxygen therapy is prescribed in litres per minute — 2 through a nasal cannula for mild supplementation, 15 through a mask with a reservoir in an emergency — and the flowmeter on the wall of a hospital room is calibrated in exactly this unit. Anaesthetic machines are set the same way.
Engines and compressors also appear here. A small air compressor delivers 100 to 200 litres per minute of free air; a car's cooling system circulates tens of litres per minute; a garden pump moves 20 to 60. In each case the number is the useful one because the equipment runs for minutes at a time rather than seconds.
Sixty litres per minute is one litre per second, so the two units differ by the same factor as the two time units. That makes the conversion easy to do mentally, and it explains why the same equipment is often described in litres per minute by its manufacturer and litres per second by the engineer designing the system it goes into.
One litre per minute equals about 0.01667 litres per second, 1,000 millilitres per minute, or about 0.22 imperial gallons per minute.