I usually see this figure in terms of eff = (volume flowrate in cfm) X (pressure in inches of water) / 6356 / (brake horsepower).
R.A. Wallis in "Axial Flow Fans" similarly puts the equation as Shaft h.p. = (5.2) X (in. water) X (cu. ft/min) / (33,000 X efficiency).
If you convert...
Looking for information on flange requirements for fans on offshore oil platforms. Is there anything in Annex F of ISO 15138 that would justify buying the standard, or does 15138 just invoke the requirements of some other standard?
