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American Society of Heating and Ventilating Engineers Guide, 1937
Chapter 34--Pipe, Fittings, Welding
perature results in an increase in length of the pipe for which provision must be made. The amount of linear expansion (or contraction in the case of refrigeration lines) per unit length of material per degree change in temperature is termed the coefficient of linear expansion of that material or commonly, the coefficient of expansion. This coefficient varies with the material.
The linear expansion of cast iron, steel, wrought-iron, #.nd copper pipe,
Metal
Cast-Iron-....... Steel-----..... \Vrought-lron_. Copper---.......
0.005441 0.006212 0.006503 0.009278
b
0.001747 0.001623 0.001622 0.001244
Table 4. Nominal Weights of Welded Wrought-Iron Pipe
Nominal Pipe Size
(Inches)
SCHED. SCHED. 10 20
Plain F.nHw
Plain Ends
Schedule 30
Plain Ends
Threads and
Couplings
Schedule 40
Schedule 60
Schedule 80
Plain Rndw
Threads and
Couplings '
Plain F.nria
Plain Rnda
The three methods by which the elongation due to thermal expansion may be taken care of are:
1. Expansion joints. 2. Swivel joints. 3. Inherent flexibility of the pipe itself utilized through pipe bends, right-angle turns, or offsets in the line.
Ys
Vs.
Ys
0.25* 0.43* 0.57*
0.25* 0.43* 0.57*
0 ??*
0.54*
0 74*
Table 5. Standard Dimensions, Weights, and Diameter and Wall Thickness Tolerances for Copper Water Tubes*
H
0.86* 0.86*
i no*
(All Tolerances Plus and Minus)
Vs.
1.14* 1.14*
1 43*
l
IH tY
2
3
3Y
4 5 6
i8
10 12
; j14 O. D.
16 O. D. 18 O. D. 20 O. D.
*
__ __
36.0 41.3 46.5
--
44.8 51.4
57.9 77.0
24.7* 34.3* 43.8*
53.6 61.4
80.5 103.0
25.0* 35.0* 45.0*
--
1.68* 2.28* 2.72*
3.66* 5.80* 7.58* 9.11* 10.8* 14.7* 19.0*
28.6* 40.5*
53.6 62.2 81.2
103.0 115.0
1.69* 2.29* 2.74* 3.68* 5.82* 7.62* 9.21* 10.9* 14.9* 19.2* 28.8* 41.2* 55.0
--
54.8* 73.2 87.6 111.0 136.0
--
2 18* 3.00*
3 <S4*
5 m*
7 67* 10.3* 12.5* 15 0* 20.8* 28.6* 43.4* 54.4 88.6 104.0
-'
--_
I IWeights are given in pounds per linear foot and are for pipe with plain ends except for sizes which are f 1commercially available with threads and couplings for which both weights are listed.
Weights marked with an asterisk in Schedules 30 and 40 are identical with weights for standard-weight pipe in former lists; those in Schedules 60 and 80'are identical with weights for extra-strong pipe in former
I flists.
Permissible
Actual
Nominal Size. In.
Outside Diam eter,
Variation in Mean Outside Diameter, In.
In.
Annealed
Hard Drawn
WALL THICKNESS, IN.
Class K
Class L
Class M
Per Per Per
Nominal
missible Varia
Nominal
missible Varia
Nominal
missible Varia
tion tion tion
Weight per Ft Lb
Class Class Class KLM
'
Xi.
*A Yi M
1
0.500 0.0025 0.001 0.049 0.004 0.035 0.0035 0.025 0.0025 0.269 0.198 0.144 0.625 0.0025 0.001 0.049 0.004 0.040 0.0035 0.028 0.0025 0.344 0.285 0.203 .0.875 0.003 0.001 0.065 0.0045 0.045 0.004 0.032 0.003 0.641 0.455 0.328 1.125 0.0035 0.0015 0.065 0.0045 0.050 0.004 0.035 0.0035 0.839 0.655 0.464
4!
ti
:I
IK IK 2
1.375 0.004 0.0015 0.065 0.0045 0.055 0.0045 0.042 0.0035 1.04 0.884 0.681 1.625 0.0045 0.002 0.072 0.005 0.060 0.0045 0.049 0.004 1.36 1.14 0.94 2.125 0.005 0.002 0.083 0.005 0.070 0.005 0.058 0.0045 2.06 1.75 1.46
2K 3
2.625 0.005 0.002 0.095 0.005 0.080 0.005 0.065 0.0045 2.92 2.48 2.03 3.125 0.005 0.002 0.109 0.005 0.090 0.005 0.072 0.0045 4.00 3.33 2.68
IK 4
3.625 0.005 0.002 0.120 0.005 0.100 0.005 0.083 0.005 5.12 4.29 3.58 4.125 0.005 0.002 0.134 0.006 0.110 0.005 0.095 0.005 6.51 5.38 4.66
5 5.125 0.005 0.002 0.160 0.006 0.125 0.006 0.109 0.005 9.67 7.61 6.65
6 6.125 0.005 0.002 0.192 0.006 0.140 0.006 0.122 0.005 13.87 10.20 8.91
From Standard Specifications for Copper Water Tube of the American Society for Testing Malertals,
The Schedule Numbers indicate approximate values of the expression 1000 x P/S.
AS.T.M. Designation B8S-33.
the materials most frequently used in heating and ventilating work, can be determined from Table 6.
The elongation values in Table 6 were computed from the following formula:
U = Lo [l + a (4oolr) +'* (too!?)2]
(1)
where
it = length at temperature t degrees Fahrenheit, feet. Lo = length at 32 F, feet. 1 = final temperature, degrees Fahrenheit, a and b are constants as follows:
628
Expansion joints of the slip-sleeve, diaphragm, or corrugated types made of copper, rubber, or other gasket material are all used for taking up expansion, but generally only for low pressures or where the inherent flexibility of the pipe cannot readily be used as in underground steam or hot water distribution lines.
Swivel joints are used extensively in low-pressure steam and hot water heating systems and in hot water supply lines. The swivel joints absorb the expansive movement of the pipe by the turning of threaded joints. In many cases the straight pipe in the offset of a swivel joint is sufficiently flexible to take up the expansion without developing enough thrust to produce swiveling in the threaded joint. This is preferable since con-