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HEATING VENTILATING AIR CONDITIONING GUIDE 1943
Table 4. Comparative Capacity of Steam Lines at Various Pitches for Steam and Condensate Flowing in Opposite Directions3
Pilch of Pipe in Inches per. 10 .Fl
Pitch or
Pipe
H i*.
K m.
1 IN.
IKn*.
2 IN.
3 m.
4 IN.
' 5 m.
Pipe Site laches*
Sq Ft Rad. Based on 240 Btu
as
Sq Ft
Sq Ft
Rad. Based on 240 Btu
> s S.
Rad. Baaed on 240 Btu
3 3 S
Sq Ft Rad. Based on 240 Btu
>
3 S
8q Ft Rad. Based on 240 Btu
Sq Ft
>
l
Rad. Based on 240
1
Btu
Sq Ft Rad. Baaed on 240 Bta -
.>e i
SqFt'
Rad. Based on 240 Btu
s?
a3
K 1
IK 1H
2
25.0 12 30.3 14 37.3 18 40.,4 19 42.5 20 46.1 21 47.5 22 49.3 23 45.8 12 52.6 15 63.0 17 70.0 20 75.2 22 83.0 23 87.9 .25 .90.2 26 104.9 18 117.2 20 133.0 23 144.5 25 154.0 27 165C0 28 172.6 29 178.2 31 142.6 18 159.0 21 181.0 23 196.5 25 209.3 27 224.0 28 234.8 30. 242.6 31 236.0 19 263.5 . 20 299.5 23 325.5 25 .346.5 27 371.5 28 388.4 29 401.1 30
Data from American Society op Heating and Ventilating Engineers Research Laboratory.
water in certain parts of the system until the steam flow is reduced sufficiently to permit the water to pass. The velocity at which such disturbances take place is a function of (1) the pipe size, whether the pipe runs horizontally of vertically, (2) the pitch of the pipe if it runs hori-
Table 5. Length in Feet of Pipe, to Se Added to Actual Length of Run-- Owing to Fittings--to Obtain Equivalent Length
Size of Pipe Inches
...Length in Feet to be Added .to Run ' Standard Elbow Side Outlet Tee Gate Valve Globe Valve.
Angle Valve
lA l 3A . . ik . 114`
2
. 2H . ,3
' 3H
'4 ' 5 6
8 10 12 14
1.3
3
0.3
14 .
7
1.8 4 :: . 0.4 18 10
2.2 5
0.5 23 . ; 12. .
3.0 3:5 .
. . . 67
0.6 29 15 0.8 34 18
4:3 , ... .8
1.0 .
46
22 :
. 5.0.
11.
l.i. -
54. ; 27 -f
. 6.5 .
. 13
.1.4-,.
66
34
. 8 '15
1.6 ' .
80
40
9
18 -
1!9
, 92
. 45' '
11
..22 -
>. 2.2
112
56. ;
13 27
2.8
136 .
.67
17 35
37 180
92
' 21 45
4.6 230
112
27 53
5.5
270 v
132
30 63
6.4 310
152
Valve in full open position:
Example of length in feet of pipe to be added to actual length of ruii.
*v
: Measured Length " .132.0 ft , '' 4 in. Gate Valve = 1.9 ft
-- Oc'O 4:--4 in. Elbows -'=_._3_6_.0_ft
y iEquivalent Length = 169.9 ft
'
1......:............. H* -.
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CHAPTER 15. PIPING FOR STEAM HEATING SYSTEMS
. Table 6. Steam Pipe Capacities Capacity Expreised.in Square Feet of Equivalent:Dirut Radiation
(Reference to this table will be by column letter A through L) This table is based on pipe size data'developed through the research investiga tions of the American Society of Heating and Ventilating Engineers.
CAPACITIES OF STEAM MAINS AND RISERS Direction or Condensation Flow in Pipe Lins
Special Capacities fob One-Pipe Ststekb Onlt
Pipe With the Steam in One-Pipe and Two-Pipe Systems
8ob In.
i/sa lb
*/*4 lb
/i lb
Klb
Klb H lb
HO. Drop
KDrop
1 Os Drop
20s Drop
4 0s Drop
80s Drop
Against the Steam
Supply
Radiator Valvea
Radiator
Two-Pipe Only Risers
Up-
Vertical
Hori zontal
Feed
and Con nections
Riser Run outs
AB C D
E
F
G H Ic jb K La
% 30
30
1
39 46 56
79 iii 157 56
114 87 100 122 173 245 346 122
\V,\ 134 155 190 269 380 538 190
2 273 315 386 546 : 771 1,091 386
VA 449 518 635 898 1,270 1,797. 635
3 .822 948 1,163 1,645 2,326 3,289 1,129
3A 1,228 1,419 1,737 2,457 3,474 4,913 1,548 4 1,738 2,011 2,457 3,475 4,914 6,950 2,042
5 3,214 3,712 4,546 6,429 9,092 12,858 ____ _
6 5,276 6,094 . 7,462 10,553 14,924 21,105 _____.
8 10,983 12,682 15,533 21,967 31,066 43,934
10 12
20,043 23,144 28,345 40,085 32,168 37,145 45,492 64,336
56,689 80,171 90,985 128,672
_____ ...
16 60,506 69,671 84,849 121,012 169,698 242,024 --
26 58 95 195 395 700 1,150 1,700 3,150
______
______
--
25 45 98 152 288 464 799 1,144 1,520
,,,,....
____ __
______
______
__ ____
--
'20 55 81 165
. ___ __ -1- ,
J_____
______ ______ ___ ^ --
20 55 81 165 260 475 745 1,110 2,180
______
-------
All Horizontal Mains and Down-Feed Risers
JpFeed Risers
Mains and Un dripped
Run outs
UpFeed Risers
Radiator Cod-
nections
Run outs Not Dripped
Note.--All drops shown are in pounds per 100 ft of equivalent run--based on pipe properly reamed. Do not use Column H for drops of 1/24 or 1/32 lb; substitute Column C or Column B as required. bDo not use Column J for drop of 1/32 lb except on sizes 3 in. and over; below 3 in. substitute Column B. eOn radiator runouts over 8 ft long increase one pipe size over that shown in Table 6. MdAh* f American Society or Heating and Ventilating Engineers ) Not to be Reprinted WlthtjOpyngnt | Heating, Piping and Air Conditioning Contractors National Association J out Special Permission
zontally, (3) the quantity of condensate flowing against the steam, and (4) freedom of the piping from water pockets which under certain con ditions act as a restriction in pipe size.
Three factors of uncertainty always exist in determining the capacity of any steam pipe. The first is variation in manufacture, which appar ently cannot be avoided. The second is the care used in reaming the ends of the pipe after cutting. The effect of both of these factors increases as the pipe size decreases. According to A.S.H.V.E. Research Laboratoiy tests, either of these factors may affect the capacity of a 1-in. pipe as much as 20 per cent. The third factor is the uniformity in grading the pipe line. All of the capacity tables given in this chapter include a factor of safety. However, the factor of safety referred to does not cover abnormal defects or constrictions nor does it cover pipe not properly reamed.
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