Measurements provided for pump and tank capacities depend on the location of the fire department described.
Imperial units are used in Canada, the United Kingdom and parts of the Commonwealth. Canadian fire departments often still refer to pump and tank capacities in UK Imperial gallons, although most have changed over to metric measurements. Officially, Canada has adopted the metric system. The Canadian fire buffing community tends to use UK Imperial measurements.
Pump capacities are referred to in IGPM (Imperial Gallons Per Minute) and tank capacities in IG (Imperial Gallons). Aerial device lengths are expressed in feet. Length/distance measurements are the same in imperial and US.
Most of the pumps on Canadian fire apparatus are American made, so the pump models are identical but simply express their capacities differently.
The United States has its own system of fluid measurement, similar to Imperial in that the units have the same names (gallons, pints, ounces). However, the actual sizes, numerically measured, are different.
Pump capacities are referred to in USGPM (United States Gallons Per Minute) and tank capacities in USG (United States Gallons).
Most of the world uses the metric system. Articles for metric countries express pump / tank capacities in litres, namely litres per minute (LPM) and simply litres for tanks.
Imperial gallons are larger than their US counterparts:
- 1 Imperial gallon = 4.5 litres
- 1 US gallon = 3.8 litres
Standard conversions are often used when referring to pumps. The math may not be exact, but these are the measurements typically used.
|US gallons per minute (USGPM)||Imperial gallons per minute (IGPM)||Litres per minute (LPM)|
|4 000||3 300||15 000|
|3 000||2 500||11 000|
|2 500||2 000||9 500|
|2 250||1 875||8 500|
|2 100||1 750||8 000|
|2 000||1 665||7 600|
|1 750||1 500||7 000|
|1 500||1 250||6 000|
|1 250||1 050||5 000|
|1 000||840||4 000|
- Size in bold are standard pump size.