Standard cubic feet per minute (SCFM) is the volumetric flow rate of a gas corrected to "standardized" conditions of temperature and pressure, making it the equivalent of the mass flow rate of the gas. However, great care must be taken, as the "standard" conditions vary between definitions and should therefore always be checked. Worldwide, the "standard" condition for pressure is variously defined as an absolute pressure of 101,325 pascals, 1.0 bar (i.e., 100,000 pascals), 14.73 psia, or 14.696 psia and the "standard" temperature is variously defined as 68 °F, 60 °F, 0 °C, 15 °C, 20 °C, or 25 °C. The relative humidity (e.g., 36% or 0%) is also included in some definitions of standard conditions. There is, in fact, no universally accepted set of standard conditions. (See Standard conditions for temperature and pressure).
The temperature variation has the largest effect. In Europe, the standard temperature is most commonly defined as 0 °C, but not always. In the United States, the standard temperature is most commonly defined as 60 °F or 70 °F, but again, not always. A variation in standard temperature can result in a significant volumetric variation for the same mass flow rate. For example, a mass flow rate of 1,000 kg/h of air at 1 atmosphere of absolute pressure is 455 SCFM when defined at 32 °F (0 °C) but 481 SCFM when defined at 60 °F (16 °C).
In countries using the SI metric system of unit, the term "normal cubic metre" (Nm3) is very often used to denote gas volumes at some normalized or standard condition. Again, as noted above, there is no universally accepted set of normalized or standard conditions.
Read more about Standard Cubic Feet Per Minute: Actual Cubic Feet Per Minute, Cubic Feet Per Minute, See Also
Famous quotes containing the words standard, cubic, feet and/or minute:
“Any honest examination of the national life proves how far we are from the standard of human freedom with which we began. The recovery of this standard demands of everyone who loves this country a hard look at himself, for the greatest achievments must begin somewhere, and they always begin with the person. If we are not capable of this examination, we may yet become one of the most distinguished and monumental failures in the history of nations.”
—James Baldwin (1924–1987)
“One of the great natural phenomena is the way in which a tube of toothpaste suddenly empties itself when it hears that you are planning a trip, so that when you come to pack it is just a twisted shell of its former self, with not even a cubic millimeter left to be squeezed out.”
—Robert Benchley (1889–1945)
“Ah done growed ten feet higher from jus’ listenin’ tuh you, Janie. Ah ain’t satisfied wid mahself no mo’.”
—Zora Neale Hurston (1891–1960)
“The minute you try to talk business with him he takes the attitude that he is a gentleman and a scholar, and the moment you try to approach him on the level of his moral integrity he starts to talk business.”
—Raymond Chandler (1888–1959)