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518
CHAPTER 27
1948 Guide
otherwise ordered. To facilitate drainage,; some elbows have the thread tapped atan angle to provide a' pitch of the connecting pipe of . in.: to the foot. 'These elbows are known to'the trade as pitch elbows and are commercially available.: All threaded pipe joints should be made up with'a thread paste suitable for the service for which the pipe is to beused:
TYPES OF FITTINGS '-v-
' Fittings for.joining the separate lengths of pipe together are made in. a variety of foirns, and are either screwed or . flanged, the.'former being generally used for the smaller sizes of pipe up to and including. 3in., and the latter'for the larger sizes, 4 in. and,above. . Screwed fittings of
Pipe, Fittings, Welding
519
War standard ratings in effect for the duration of the emergency, per- mitted higher ratings for certain sizes of the 125 lb cast-iron flanged fitting standard,.and for- 300.1b steel flanges and flanged fittings than those shown in the regular American Standards mentioned previously..
Screwed fittings include: nipples'or short pieces of pipe-of varying lengths; couplings of steel or :wrought-iron; elbows for turning angles of either 45 deg or 90 deg; return bends, which may be of either the close
Table 5. American Standard Dimensions of Elbows, Tees, Crosses, and 45 Deg Elbows, Soldered-Joint Fittings, A.S.A. A40.3-1941
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FUUKD-niBlNG FITTiNGS ' Fig. 2. Copper or Brass .Tubing Fittings ;
,.
large size as well as flanged fittings of small size are also made and are used for certain classes of work at the proper pressure. .
The material used for fittings is.generally cast-iron, but in addition' to this, malleable-iron, steel and steel alloys are also used, as well as various grades of. brass or bronze. The material to be used depends, on-the character of the service and the pressure. Malleable iron fittings,, like brass fittings, are cast with a round instead of a flat band or bead, or with no bead at all. Fittings are designated as male or female, depending on whether the threads are on the outside or inside, respectively. Screwed galvanized fittings are made according to the 150 lb American Standard.
As in the case of pipe, several weights of fittings are manufactured. Recognized American Standards for the various weights are as: follows:
' 'Cast-iron pipe flanges and flanged fittings for 25 lb (sizes 4 in. and larger), 125 lb, and 250 lb maximum saturated steam pressure, A.S.A. B16b2, B16a, and B16b.respective|y.
Malleable.iron screwed fittings for 150 lb maximum saturated steam pressure, A.S.A. B16c.
Cast-iron screwed fittings for 125 and 250 lb maximum saturated steam pressure, /4.5./1. B16d.
Steel flanged fittings for 150 and 300 lb maximum steam service pressure, A.SA. B16e.
The allowable cold water working pressures for these standards vary from 43 lb for the 25 lb standard to 500 lb for the 300 lb steel standard.-
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Nominal Size*
X
X 1
ix
2
2X
3 3% 4 5
6
Laying Length, Tee, Eli. and Croesb
Laying
Length. EU With External
Shoulder
Laying Length, 45 Deg
Ell
Trying Inside
Length. Diameter
45 Deg Ell
of
External FHtings.e
Shoulder. Min.
H;
J QO
X . % . Xt
X 0.31
/He Xa Xa 0.43
- As
He ' Xa Xs
0.54
Hs . %. . X - Vi
X
%
Xa ,
Xa
0.78 1.02
Vi i
.%
1
ix
:X
Xa 1.26 X 1.50
IX
m
'Xa
X 1.98
m Vi X 2.46
m IX
X1
2.94
2 2X X ix 3.42
2X 2Va
% m: 3.90
3X ___
IXb
4.87
Wi -- m -- 5.84
Metal Thickness*
Wrought
Metal
Boas or
Metal FrmNoa Thickness*
Min.1
T
0.08 0.08 0.09 0.10 0.11 0.12 0.13 0.15 0.17 0.19 0.20 0.22 0.28 0.34
.R
0.048 0.048 0.054 0.060 0.066 0.072 0.078 0.090 0.102 0.114 0.120 0.132 0.168 0.204
T and R
0.030 0.035 0.040 0.045 0.050 0.055 0.060 0.070 0.080 0.090 0.100 0.110 0.125 0.140
E, Mm.
0.378 0.503 0.628 0.878 1.1285 1.3785 1.629 2.129 2.629 3.129 3.629 4.129 5.129 6.129
- All dimensions, given in inches. '
"This size is the nominal bore of the tube.
bThese dimensions may be used for wrought-metal fittings as well as for cast-brass fittings at manu facturer 8 option.
"This dimension is the same as the inside diameter Class L tubing (American Standard Specifications for Copper Water Tube. AS.A. H23.1-1939 (AS.T.M. B88).
- ^patterns shall be designed to produce body thicknesses given in the table. Metal thickness at no point shall be less than 90 per cent of the thicknesses given in the table.
"This dimension has the same thiHmpgg as Type L tubing.
fThese dimensions are minimum, but in every case the thickness of wrought fittings should be at least as heavy as the tubing with which it is to be used.
Note 1:--Wrought fittings, as well as cast fittings, must be provided with a shoulder or stop at the
bottom end of socket.
*
Note 2:--Street fittings with male ends are for use in connection with other fittings illustrated.
or open pattern, and may be cast with either a back or side outlet; tees; crosses; laterals or Y branches; and a variety of plugs, bushings, caps, lock-nuts, flanges and reducing .fittings. Reducing fittings as well as bushings, both of which are used in changing from one pipe size to another, may have the smaller connection tapped eccentrically to permit free drain-