H. C A R L B A U M A N
UP-TO-DATE EQUIPMENT COSTS ’
A cost re$rence @le which rejects the latest quotations on 7.9 major categories o f chemical process equipment together with an equation f o r keeping the quotations current
.
for the process plant is the largest single cost. I t is therefore most desirable to maintain up-to-date equipment cost data for immediate use without resorting to the time-consuming process of obtaining new quotations for each new projcct. Methods of maintaining an equipment cost data file have b e m discussed in I&EC in the past. The most successful method is based on plotting actual quoted costs obtained over a restricted time period for a specific kind of equipment. Such a plot for carbon steel towers less internals is shown in Figure l a . The curve fitted to the data on linear coordinate paper was then used to seplot on log-log cross section paper as shown in Figure Ib. If the new plot is still curved on log-log paper, compromise straight lines are fitted in a manner to limit the error to less than =t5’%. This results in two or more straight lines replacing the curved plot. The slope of these lines can readily be obtained and an equation written, giving the cost of the item over the size os capacity ranges covered by each straight line segment. Thus the cost exponent for carbon steel towers weighing from GO00 to 20,000 pounds is 0.790, while towers in the QUIPWENT
Ei t a n of fixed capital
H. Carl Bauman is Manager of the Cost Engineering Department, Engineering and Construction Division of American Cyanamid. He has authored I B E C ’ s Costs feature on alternate months since April 7958.
AUTHOR
VOL. 5 4
NO.
1
JANUARY
1962
49
-I ,
23
60
,
l
l
l
I
/
260 300
223
140 180 WEIGHT, 1030 POUNDS 100
6C 40 -
b
20 0 0
5 10-
tFt b--
5-
6w
4-
1.176-
LC.523-
2 '
,
4
,
I
I
I
I ,
6 8 1 0
20
40 60 WEIGHT 'OC0 POUNDS
1
I
103
290
300
Figure 7. The most successful method of maintaining a cost data file zs based on plotting actual quoted costs a. b.
T h e curue ,for carbon steel towers less internals z i Jitted to data on lanear coordinate paper T h e curne rep lotted on log-log cross-section paper
range of 20,000 to 300,000 pounds have a cost exponent of 0.710. Therefore, the cost of a 15.000-pound tohvar can be estimated from the cost figure for a 6000-pound towcr. = c 6 (15/6)o.79° = $2930 (2.5)0.793 = $6,050
The cost of a 60,000-pound tower is similarly estimated from the cost figure for a 20,000-pound tower.
c60 =
c20(60/20)0.7'o
= $7,600 (3)0.710 =
$16,500
A table covering a variety of equipment frequently used in chemical process plants was compiled using the techniques described. All costs may be considered as current to October 1961. In arriving a t the equipment costs shown in the table, many sources of information were screened. Cost information in the literature was compared carefully with actual cost data from vendors' quotations and invoices, all corrected to late 1961 prices. Spot checks were made 50
INDUSTRIAL A N D E N G I N E E R I N G CHEMISTRY
to validate accuracy, When good correlations could not be established, a price for the item, based on several new quotations, was used. Thus, validity of equipment costs among several authorative sources could be checked.
Process Equipment Cost Data BLOWERS AND FANS
Sire 1 3 7 5
Centrifugal blower a n d motor (size unit, hP.)
??,
4%
Draft blower, axial flown (size unit, 1000 cu. ft./min.) F a n a n d 1750 r.p.m. motor
Cost,
8
490 590 830
Sire Range 1-3 3-7.5 7.5-350
Exfonent 0.16 0.37 0.96
2 4 12 28
720 790 1,200 2,100
2-4 4-1 2 12-28 28-36
0 13 0.38 0 66 0.17
Fan a n d 1750 r.p.m. turbine*
4 8 14
950 1,150 1,500
4-8 8-14 14-22
0 28 0 47 0 31
F a n and 2500 r.p.m. turbine*
5 12 22
760 1,030 1,440
5-1 2 12-22 22-35
0.34 0.56 0.39
F a n a n d 3500 r.p.m. turbine6
1 4
430 600
1-4 4-6
0.24 0.34
Y
2-in. static press.
a
b 275 p . s . i . s f m m .
Extras, Flanged unit for vertical mounting on duct or windbox, add 7 % . Multi-vane damper add $500 to $3650. Multi-vane damper with governor, add $950 to $1250. Stkam turbine 600 p.s.i. steam add 5450. Turbine overspeed trip governor, add $300. Turdine steam straine;, relief valve, and mounting feet, add $70 to $300. Combined motor-turbine drive on same blower including multi-vane damper = motor-driven unit plus turbine-driven unit plus 10%.
Draft inducer, axial flowa (size unit, 1000 cu. ft./ min.) a
1 3 6
7750 r.p.m.
0.5- to 7.0-in.static press;
530 760 1,120
1-3 3-6 6-20
0.32 0.55 0.78
Zncludes f a n and hotisin,
