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798 ________________ Chapter 48
. 1945 Guide
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Thermal resistance (degree per unit of heat transferred per unit time)...... .................... R
Thermal resistivity___ _______________ -._____________ .......................... ............................ 1/k Vaporization values at constant pressure. Differences between values for saturated
vapor and saturated liquid at the same pressure__ ________ __________ Subscript fE Velocity;___________ ___________ ______________________ :V Volume (total)._____________________ :t1..V
Volume per unit time, Rate at which quantity of material- passes through a machine, Quantity of heat per unit time, Quantity of heat per unit weight_____
Weight of a major item. Total weight..............................................:...i________ ; Weight rate, Weight per unit of power, Weight per unit of time.... :................................ Work (total)............................,.............................:................................................1_____.........
CONVERSION EQUATIONS5
Heat Power and Work
1 ton refrigeration Latent heat of ice 1 Btu
1 Inf. watthour
1 Int. kilowatthour
1 Int. kilowatt (1000 watts) 1000 I.T. calories \ 1 I.T. Kilocalorie /
1 horsepower
1 boiler horsepower
_ / 12,000 Btu per hour \ 200 Btu per minute
= 143.4 Btu per pound
778.3 ft-lb 0.2930 Int. whr 252.0 I.T. calorie
2656 ft-lb 3.413 Btu 3600 Int. joules 860 I.T. calories
3.413 Btu 3.517 lb water evaporated from
and at 212 F
1.341 hp 56.88 Btu per minute 44,267 ft-lb per minute
3.968 Btu 3088 ft-lb 1.1628 Int. whr
0.7455 Int. kw 42.40 Btu per minute 33,000 ft-lb per minute 550 ft-lb per second
/ 33,475 Btu per hour \ 9.809 Int. kw
Weight and Volume.
1 gal (U. S.)
1 British or Imperial gallon -
1 cu ft
1 cu ft water at 60 F (in vacuo.) 1 cu ft water at 212 F ( " " ) 1 gal water at 60 F ( " " ). 1 gal water at 212 F ( " `` )
1 lb (avdp)
1 bushel 1 short ton
/ 231 cu in. \ 0.1337 cu ft = 277.42 cu in.
_ / 7.481 gal " \ 1728 cu in.
= 62.37 lb
= 59.831b
= 8.338 lb = 7.998 lb
! 16 oz l 7000 grains
= 1.244 cu ft
= 20001b
. *Checked in 1944 by National Bureau of Standards. Abbreviations Int. and I.T. refer to International and International {Steam)' Table respectively.
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Abbreviations, Symbols, Standards
799
Pressure
1 lb per square inch 1 oz per square inch . 1 atmosphere
1 in. water at 62 F (in vacuo) 1 ft water at.62 F (in vacuo) 1 in. mercury at 62 F (in vacuo)
. Metric Units
(144 lb per square foot 2.0422 in. mercury at 62 F 2.309 ft water at 62 F 27.71 in. water at 62 F
/ 0.1276 iri. mercury at 62 F - \ 1.732 in. water at 62 F
14.696 lb per square inch 2116 lb per square foot 33;94 ft water at 62 F 30.01 in. mercury at 62 F
29.921 in. mercury at 32 F
{
0.03609 lb per square inch 0.5774 oz per square inch
5.197 lb per square foot
-{
0.4330 lb per. square inch 62.37 lb per sguare foot
0.4897 lb per square inch 7.835 oz per square inch 1.131 ft water at 62 F 13.57 in. water at 62 F
1 cm 1 in.
l.m.
1 ft ' 1 sq cm 1 sq in. 1 sq m 1 sq ft 1 cu cm 1 cu in. 1 cu m 1 cu ft 1 liter 1 kg lib 1 metric ton 1 gram 1 kilometer per hour
1 gram per square centimeter
1 kg per sq cm (metric atmosphere)
1 gram per cubic centimeter
1 dyne
1 absolute joule
1 Int. joule
1 metric horsepower
1 I. T. kilocalorie per kilogram
= 0.3937 in. = 2.540 cm = 3.281 ft
= 0.3048 m = 0:1550 sq in. = 6.452 sq cm = 10.76 sq ft , = 0.09290 sq m = 0.06102 cu in.
! = 16:39 cu cm
= 35.31 cu ft = 0.02832 cu m
= 1000 cu cm = 0.2642 gal = 2.205 lb (avdp)
= 0.4536 kg = 2205 lb (avdp) .
= 0.002205 lb (avdp) = 0.6214 mph
_ / 0.02905 in. mercury at 62 F l 0.3942 in. water at 62 F
= 14.22 lb per square inch = / 0.03613 lb per cubic inch
\ 62.43 lb per cubic foot = 0.00007233 poundals _ / 10,000,000 ergs " \ 0.7376 ft-lb = 0.7378 ft-lb _ / 75 kg-m per second " \ 0.986 hp (U. S.) = 1.8 Btu per pound
1 I.T. calorie per square centimeter
= 3.687 Btu per square foot
1 I.T. calorie per second per square centimeter f 2903 Btu per hour per square
tor a temperature gradient of 1 deg C per centi- - { foot for a temperature gradient
meter
I of 1 deg F per inch of thickness.