New York Codes, Rules and Regulations › Title 12 - DEPARTMENT OF LABOR › Appendices › Appendix A-1

Current through Register Vol. 46, No. 28, July 10, 2024
Note: Explanatory of Subparts 14-11 and 14-12 and
				containing matter which is not mandatory unless specially referred to in the
				sections therein.
SECTION 1
EFFICIENCY OF JOINTS
A-1 Efficiency of riveted joints.
The ratio which
				the strength of a unit length of a riveted joint has to the same unit length of
				the solid plate is known as the efficiency of the joint and shall be calculated
				by the general method illustrated in the following examples:
TS
= tensile strength stamped on plate, pounds
				per square inch.
t
= thickness of plate, inches.
b
= thickness of buttstrap, inches.
P
= pitch of rivets, inches, on row having
				greatest pitch.
d
= diameter of rivet after driving, inches, =
				diameter of rivet hole.
a
= cross-sectional area of rivet after
				driving, square inches.
s
= shearing strength of rivet in single
				shear, pounds per square inch, as given in section
				14-11.20.
S
= shearing strength of rivet in double
				shear, pounds per square inch, as given in section
				14-11.20.
c
= crushing strength of mild steel, pounds
				per square inch, as given in section
				14-11.19.
n
= number of rivets in single shear in a unit
				length of joint.
N
= number of rivets in double shear in a unit
				length of joint.
A-2 Example: lap joint, longitudinal or circumferential,
				single-riveted.
A
= strength of solid plate =
P × t ×
				TS.
B
= strength of plate between rivet holes =
(P - d)t × TS.
C
= shearing strength of one rivet in single
				shear =
n × s × a.
D
= crushing strength of plate in front of one
				rivet =
d × t × c.
Divide B, C, or D (whichever is the least) by A, and the
				quotient will be the efficiency of a single-riveted lap joint as shown in
				Figure A-1.
TS
= 55,000 psi
t
= 1/4 in. = 0.25 in.
P
=
				15/8in. = 1.625 in.
d
=
				11/16 in. = 0.6875 in.
a
= 0.3712 sq. in.
s
= 44,000 psi
c
= 95,000 psi
A
= 1.625 × 0.25 × 55,000 = 22,343
B
= (1.625 - 0.6875)0.25 × 55,000 = 12,890
				.......
C
= 1 × 44,000 × 0.3712 = 16,332
D
= 0.6875 × 0.25 × 95,000 = 16,328
12,890(B)
= 0.576 = efficiency of joint
				22,343(
A
) .......
Click
				to view image
Note:
Reference herein to specifications SA
				(ferrous) or SB (nonferrous) shall be understood to mean SA or SB
				specifications as published by the A.S.M.E. with latest addenda.
A-3 Example: lap joint, longitudinal or circumferential,
				double-riveted.
A
= strength of solid plate =
P × t ×
				TS.
B
= strength of plate between rivet holes =
(P - d)t × TS.
C
= shearing strength of two rivets in single
				shear =
n × s × a.
D
= crushing strength of plate in front of two
				rivets =
n × d × t × c.
Divide
B, C,
or
D
(whichever
				is the least) by
A,
and the quotient will be the efficiency of
				a double-riveted lap joint, as shown in Figure A-2.
TS
= 55,000 psi
t
=
				5/16 in. = 0.3125 in.
P
= 2
				7/8 in. = 2.875 in.
d
= 3/4 in. = 0.75 in.
a
= 0.4418 sq. in.
s
= 44,000 psi
c
= 95,000 psi
A
= 2.875 × 0.3125 × 55,000 = 49,414
B
= (2.875-0.75)0.3125 × 55,000 = 36,523
				.......
C
= 2 × 44,000 × 0.4418 = 38,878
D
= 2 × 0.75 × 0.3125 × 95,000 = 44,531
				.......
36,523(B)
= 0.739 = efficiency of joint.
				49,414(
A
) .......
Click
				to view image
A-4 Example: butt- and double-strap joint,
				double-riveted.
A
= strength of solid plate =
P × t ×
				TS.
B
= strength of plate between rivet holes in
				the outer row =
(P - d)t × TS
C
= shearing strength of two rivets in double
				shear, plus the shearing strength of one rivet in single shear =
N × S
				× a + n × s × a.
D
= strength of plate between rivet holes in
				the second row, plus the shearing strength of one rivet in single shear in the
				outer row =
(P - 2d)t × TS + n × s × a.
E
= strength of plate between rivet holes in
				the second row, plus the crushing strength of buttstrap in front of one rivet
				in the outer row =
(P - 2d)t × TS + d × b × c.
F
= crushing strength of plate in front of two
				rivets, plus the crushing strength of buttstrap in front of one rivet =
N × d × t × c + n × d × b × c.
G
= crushing strength of plate in front of two
				rivets, plus the shearing strength of one rivet in single shear =
N × d
				× t × c + n × s × a.
H
= strength of buttstraps between rivet holes
				in the inner row =
(P - 2d) 2b × TS.
This method of failure is not possible for thicknesses of
				buttstraps required by these rules and the computation need only be made for
				old boilers in which thin buttstraps have been used. For this reason this
				method of failure will not be considered in other joints.
Divide
B, C, D, E, F, G,
or
H
(whichever is the least) by
A,
and the quotient will be the
				efficiency of a butt- and double-strap joint, double-riveted, as shown in
				Figure A-3.
TS
= 55,000 psi
t
=
				3/8 in. = 0.375 in.
b
=
				5/16 in. = 0.3125 in.
P
= 4
				7/8in. = 4.875 in.
d
=
				7/8 in. = 0.875 in.
a
= 0.6013 sq in.
s
= 44,000 psi
S
= 88,000 psi
c
= 95,000 psi
Number of rivets in single shear in a unit length of joint = 1.
				Number of rivets in double shear in a unit length of joint = 2. .......
A
= 4.875 × 0.375 × 55,000 = 100,547
B
= (4.875 0.875) 0.375 × 55,000 =
				82,500
C
= 2 × 88,000 × 0.6013 + 1 × 44,000 × 0.6013
				= 132,286
D
= (4.875 - 2 × 0.875) 0.375 × 55,000 + 1 ×
				44,000 × 0.6013 = 90,910
E
= (4.875 - 2 × 0.875) 0.375 × 55,000 + 0.875
				× 0.3125 × 95,000 = 90,429
F
= 2 × 0.875 × 0.375 × 95,000 + 1 × 0.875 ×
				0.3125 × 95,000 = 88,320
G
= 2 × 0.875 × 0.375 × 95,000 + 1 × 44,000 ×
				0.6013 = 88,800
82,500(B)
= 0.820 = efficiency of joint.
				100,547(
A
) .......
Click
				to view image
A-5 Example: butt- and double-strap joint,
				triple-riveted.
A
= strength of solid plate =
P × t ×
				TS.
B
= strength of plate between rivet holes in
				the outer row =
(P - d) t × TS.
C
= shearing strength of four rivets in double
				shear, plus the shearing strength of one rivet in single shear =
N × s
				× a + n × s × a.
D
= strength of plate between rivet holes in
				the second row, plus the shearing strength of one rivet in single shear in the
				outer row =
(P - 2d) t × TS + a × s × a.
E
= strength of plate between rivet holes in
				the second row, plus the crushing strength of buttstrap in front of one rivet
				in the outer row =
(P - 2d) t × TS + d × b × c.
F
= crushing strength of plate in front of
				four rivets, plus the crushing strength of buttstrap in front of one rivet =
N × a × t × c + n × d × b × c.
G
= crushing strength of plate in front of
				four rivets, plus the shearing strength of one rivet in single shear =
N × d × t × c + a × s × a.
Divide
B, C, D, E, F,
or
G
(whichever is the least) by
A,
and quotient will be the
				efficiency of a butt- and double-strap joint, triple-riveted, as shown in
				Figure A-4.
TS = 55,000 psi
t = 3/8 in. =
				0.375 in.
b = 5/16 in.
				= 0.3125 in.
P = 6 1/2 in. = 6.5 in.
d = 13/16 in.
				= 0.8125 in.
a = 0.5185 sq. in.
s = 44,000 psi
S = 88,000 psi
c = 95,000 psi
Number of rivets in single shear in a unit length of joint = 1.
				Number of rivets in double shear in a unit length of joint = 4. .......
A
= 6.5 × 0.375 × 55,000 = 134,062
B
= (6.5 - 0.8125) 0.375 × 55,000 =
				117,304
C
= 4 × 88,000 × 0.5185 + 1 × 44,000 × 0.5185
				= 205,326
D
= (6.5 - 2 × 0.8125) 0.375 × 55,000 + 1 ×
				44,000 × 0.5185 = 123,360
E
= (6.5 - 2 × 0.8125) 0.375 × 55,000 + 0.8125
				× 0.3125 × 95,000 = 124,667
F
= 4 × 0.8125 × 0.375 × 95,000 + 1 × 0.8125 ×
				0.3125 × 95,000 = 139,902
G
= 4 × 0.8125 × 0.375 × 95,000 + 1 × 44,000 ×
				0.5185 = 138,595
117,304(B)
= 0.875 = efficiency of joint.
				134,062(
A
) .......
Click
				to view image
A-6 Example: butt- and double-strap joint,
				quadruple-riveted.
A
= strength of solid plate =
P × t ×
				TS.
B
= strength of plate between rivet holes in
				the outer row =
(P - d) t × TS.
C
= shearing strength of eight rivets in
				double shear, plus the shearing strength of three rivets in single shear =
N × S × a + n × s × a.
D
= strength of plate between rivet holes in
				the second row, plus the shearing strength of one rivet in single shear in the
				outer row =
(P - 2d) t × TS + 1 × s × a.
E
= strength of plate between rivet holes in
				the third row, plus the shearing strength of two rivets in the second row in
				single shear and one rivet in single shear in the outer row =
(P - 4d)
				× TS + a × s × a.
F
= strength of plate between rivet holes in
				the second row, plus the crushing strength of buttstrap in front of one rivet
				in the outer row =
(P - 2d) t × TS + a × b × c.
G
= strength of plate between rivet holes in
				the third row, plus the crushing strength of buttstrap in front of two rivets
				in the second row and one rivet in the outer row =
(P - 4d) t × TS + n
				× d × b × c.
H
= crushing strength of plate in front of
				eight rivets, plus the crushing strength of buttstrap in front of three rivets
				=
N × d × t × c + n × d × b × c.
I
= crushing strength of plate in front of
				eight rivets, plus the shearing strength of two rivets in the second row and
				one rivet in the outer row, in single shear =
N × d × t × c + n × s ×
				a.
Divide
B, C, D, E, F, G, H,
or
I
(whichever is the least) by
A,
and the
				quotient will be the efficiency of a butt- and double-strap joint,
				quadruple-riveted, as shown in Figure A-5.
TS = 55,000 psi
t = 1/2 in. = 0.5 in.
b = 7/16 in.
				= 0.4375 in.
P = 15 in.
d = 15/16 in.
				= 0.9375 in.
a = 0.6903 sq. in.
s = 44,000 psi
S = 88,000 psi
c = 95,000 psi
Number of rivets in single shear in a unit length of joint = 3.
				Number of rivets in double shear in a unit length of joint = 8. .......
A
= 15 × 0.5 × 55,000 = 412,500
B
= (15 - 0.9375) 0.5 × 55,000 =
				386,718
C
= 8 × 88,000 × 0.6903 + 3 × 44,000 × 0.6903
				= 577,090
D
= (15 - 2 × 0.9375) 0.5 × 55,000 + 1 ×
				44,000 × 0.6903 = 391,310
E
= (15 - 4 × 9.0375) 0.5 × 55,000 + 3 ×
				44,000 × 0.6903 = 400,494
F
= (15 - 2 × 0.9375) 0.5 × 55,000 + 0.9375 ×
				0.4375 × 95,000 = 399,902
G
= (15 - 4 × 0.9375) 0.5 × 55,000 + 3 ×
				0.9375 × 0.4375 × 95,000 = 426,269
H
= 8 × 0.9375 × 0.5 × 95,000 + 3 × 0.9375 ×
				0.4375 × 95,000 = 473,145
I
= 8 × 0.9375 × 0.5 × 95,000 + 3 × 44,000 ×
				0.6903 = 447,369
386,718(B)
= 0.937 = efficiency of joint.
				412,500(
A
) .......
Click
				to view image
A-7
Figures A-6 and A-7 illustrate other joints
				that may be used in which eccentric stresses are avoided. The butt- and
				double-strap joint with straps of equal width shown in Figure A-6 may be so
				designated that it will have an efficiency of from 82 to 84 per cent and the
				saw-tooth joint shown in Figure A-7 so that it will have an efficiency of from
				92 to 94 per cent.
Click
				to view image
SECTION 2
BRACED AND STAYED SURFACES
A-8
(a) The allowable loads based on the net
				cross-sectional areas of staybolts with V threads are computed from the
				following formulas. The use of Whitworth threads with other pitches is
				permissible.
(1) The formula for the diameter of a staybolt at the bottom of
				a V thread is:
D
- (
P
× 1.732) =
d
.
where
D
= diameter of staybolt over the
				threads, inches,
P
= pitch of threads, inches, = 1/number of
				threads per inch,
d
= diameter of staybolt at bottom of
				threads, inches, 1.732 = a constant. .......
(2) When U. S. threads are used, the formula becomes:
D
- (
P
× 1.732 × 0.75) =
d.
(b) Tables A-1 and A-2 give the allowable loads on net
				cross-sectional areas for staybolts with V threads having 12 and 10 threads per
				inch.
Click
				to view image
Click
				to view image
Click
				to view image
A-10
Table A-4 gives the net areas of segments of
				heads for use in computing stays.
TABLE A-4
Net Areas of Segments of Heads Where d, as Given in
				Sections 14-11.107 (subd. [a]) and
				14-11.108, Is Equal to Three Inches
Height from tubes to shell, inches
Diameter of boiler, inches
24
30
36
42
48
54
60
66
72
78
84
90
96
Area to be stayed, square inches
8
28
33
37
40
43
47
51
53
55
58
60
63
65
81/2
35
41
46
51
55
59
63
66
70
74
76
80
82
9
42
49
56
62
67
72
76
82
86
90
92
95
98
91/2
50
58
66
70
80
86
91
96
101
105
111
116
119
10
57
68
77
85
93
99
106
112
117
123
129
132
137
101/2
66
78
89
98
107
114
123
131
135
142
147
153
160
11
74
88
100
111
121
130
138
147
155
161
169
174
183
111/2
83
99
112
124
137
146
156
165
173
181
189
196
204
12
91
109
125
139
151
163
174
184
194
203
213
219
230
121/2
.......
120
138
153
167
180
193
204
216
224
234
243
252
13
.......
132
151
168
183
197
211
224
235
247
256
267
279
131/2
.......
143
164
183
200
216
230
246
258
270
282
293
302
14
.......
155
178
199
217
234
250
266
280
294
305
319
331
141/2
.......
167
192
215
235
254
271
287
303
318
333
345
360
15
.......
178
206
231
252
273
291
309
326
343
357
372
386
151/2
.......
.......
220
247
271
291
312
332
350
368
382
400
417
16
.......
.......
235
263
289
312
334
355
374
394
411
423
443
161/2
.......
.......
249
281
308
332
357
380
399
420
436
457
475
17
.......
.......
264
297
326
353
378
402
425
447
467
486
502
171/2
.......
.......
.......
314
345
374
400
426
449
471
494
516
536
18
.......
.......
.......
331
365
396
424
450
476
500
520
543
564
181/2
.......
.......
.......
349
384
417
448
476
501
526
552
577
598
19
.......
.......
.......
366
404
439
470
500
529
555
580
604
631
191/2
.......
.......
.......
384
424
461
496
528
558
584
613
641
663
20
.......
.......
.......
401
444
483
519
552
583
613
642
667
699
201/2
.......
.......
.......
.......
464
505
543
578
613
643
675
706
729
21
.......
.......
.......
.......
485
528
568
604
640
673
705
733
766
211/2
.......
.......
.......
.......
505
551
594
632
669
703
739
766
797
22
.......
.......
.......
.......
526
574
618
658
697
734
769
800
835
221/2
.......
.......
.......
.......
.......
597
574
687
726
765
800
835
867
23
.......
.......
.......
.......
.......
620
668
713
754
796
830
869
906
231/2
.......
.......
.......
.......
.......
642
695
740
784
827
866
904
945
24
.......
.......
.......
.......
.......
667
719
768
814
859
897
939
978
241/2
.......
.......
.......
.......
.......
689
745
797
843
892
934
975
1018
25
.......
.......
.......
.......
.......
714
771
825
875
922
966
1010
1051
251/2
.......
.......
.......
.......
.......
737
798
855
907
956
1003
1047
1092
26
.......
.......
.......
.......
.......
761
824
882
936
987
1035
1083
1126
261/2
.......
.......
.......
.......
.......
.......
850
909
968
1024
1073
1120
1167
27
.......
.......
.......
.......
.......
.......
877
939
998
1053
1106
1157
1202
271/2
.......
.......
.......
.......
.......
.......
904
968
1030
1089
1145
1195
1243
28
.......
.......
.......
.......
.......
.......
930
997
1060
1120
1177
1232
1279
281/2
.......
.......
.......
.......
.......
.......
.......
1028
1092
1157
1211
1270
1321
29
.......
.......
.......
.......
.......
.......
.......
1056
1123
1187
1248
1305
1360
291/2
.......
.......
.......
.......
.......
.......
.......
1084
1155
1221
1284
1347
1400
30
.......
.......
.......
.......
.......
.......
.......
1115
1187
1255
1321
1382
1442
301/2
.......
.......
.......
.......
.......
.......
.......
.......
1218
1290
1358
1424
1480
31
.......
.......
.......
.......
.......
.......
.......
.......
1252
1324
1394
1459
1523
311/2
.......
.......
.......
.......
.......
.......
.......
.......
1286
1359
1433
1496
1561
32
.......
.......
.......
.......
.......
.......
.......
.......
1317
1394
1467
1538
1605
321/2
.......
.......
.......
.......
.......
.......
.......
.......
.......
1430
1508
1575
1650
33
.......
.......
.......
.......
.......
.......
.......
.......
.......
1465
1542
1617
1687
331/2
.......
.......
.......
.......
.......
.......
.......
.......
.......
1500
1578
1655
1733
34
.......
.......
.......
.......
.......
.......
.......
.......
.......
1536
1617
1695
1770
341/2
.......
.......
.......
.......
.......
.......
.......
.......
.......
.......
1654
1735
1816
35
.......
.......
.......
.......
.......
.......
.......
.......
.......
.......
1692
1775
1856
351/2
.......
.......
.......
.......
.......
.......
.......
.......
.......
.......
.......
1810
1900
36
.......
.......
.......
.......
.......
.......
.......
.......
.......
.......
.......
1857
1941
361/2
.......
.......
.......
.......
.......
.......
.......
.......
.......
.......
.......
.......
1984
37
.......
.......
.......
.......
.......
.......
.......
.......
.......
.......
.......
.......
2026
SECTION 3
METHOD OF CHECKING SAFETY-VALVE CAPACITY BY MEASURING
				MAXIMUM AMOUNT OF FUEL THAT CAN BE BURNED
A-12
The maximum quantity of fuel
C
that can be burned per hour at the time of maximum forcing
				is determined by a test. The maximum number of heat units per hour, or
CH,
is then determined, using the values of
H
given in paragraph A-17. The weight of steam generated per hour is found by the
				formula:
W
=
C × H × 0.75
1100
				.......
where
W
= weight of steam generated per hour,
				pounds,
C
= total weight or volume of fuel burned per hour at
				time of maximum forcing, pounds or cubic feet, .......
H
= heat of combustion of fuel, Btu per pound
				or per cubic foot (see par. A-17).
The sum of the safety-valve capacities marked on the valves
				shall be equal to or greater than
W
.
A-13 Example 1.
A boiler at the time of maximum
				forcing uses 2,150 pounds of Illinois coal per hour of 12,100 Btu per pound.
				Boiler pressure is 225 psi gage.
C
×
H
= 2150 × 12,100 =
				26,015,000
W
=
C
×
H
×
				0.75 ÷ 1100 = 17,740
A-14 Example 2.
Wood shavings of heat of
				combustion of 6,400 Btu per pound are burned under a boiler at the maximum rate
				of 2,000 pounds per hour. Boiler pressure is 100 psi gage.
C
×
H
= 2000 × 6400 =
				12,800,000
W
=
C
×
H
×
				0.75 + 1100 = 8730
A-15 Example 3.
An oil-fired boiler at maximum
				forcing uses 1,000 pounds of crude oil (Texas) per hour. Boiler pressure is 275
				psi gage.
C
×
H
= 1000 × 18,500 =
				18,500,000
W
=
C
×
H
×
				0.75 + 1100 = 12,620
A-16 Example 4.
A boiler fired with natural gas
				consumes 3,000 cubic feet per hour. The working pressure is 150 psi
				gage.
C
×
H
= 3000 × 960 =
				2,880,000
W
=
C
×
H
×
				0.75 + 1100 = 1960
A-17
For the purpose of checking the safety-valve
				capacity as described in paragraph A-12, the following values of heats of
				combustion of various fuels may be used:
H
=BTU per
						  lb.
Semibituminous coal .......
14,500
Anthracite .......
13,700
Screenings .......
12,500
Coke .......
13,500
Wood, hard or soft, kiln dried .......
7,700
Wood, hard or soft, air dried .......
6,200
Wood shavings .......
6,400
Peat, air dried, 25 per cent moisture .......
7,500
Lignite .......
10,000
Kerosene .......
20,000
Petroleum, crude oil, Pennsylvania .......
20,700
Petroleum, crude oil, Texas .......
18,500
H =
BTU per cu
						  ft.
Natural gas .......
960
Blast-furnace gas .......
100
Producer gas .......
150
Water gas, uncarbonated .......
290
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SECTION 4
AUTOMATIC WATER GAGES
A-18
Automatic shutoff valves on water gages, if
				permitted to be used, shall conform to the following requirements:
(a) Check valves in upper and lower fittings shall be of solid
				noncorrosive metal ball type to avoid need for guides.
(b) Ball check valves in upper and lower fittings must open by
				gravity and the lower ball check valve must rise vertically to its seat.
(c) The check balls must not be smaller than one-half inch
				diameter, and the diameter of the circle of contact with the seat must not be
				greater than two thirds of the diameter of the check ball. The space around
				each ball must be not less than one-eighth inch, and the travel movement from
				the normal resting place to the seat must be not less than one-quarter
				inch.
(d) The ball seat in the upper fitting must be a fiat seat with
				either a square or hexagonal opening, or otherwise arranged so that the steam
				passage can never be completely closed by this valve.
(e) The shutoff valve in the upper fitting must have a
				projection which holds the ball at least one-quarter inch away from its seat
				when the shutoff valve is closed.
(f) The balls must be accessible for inspection. Means must be
				provided for removal and inspection of the lower ball check valve while the
				boiler is under steam pressure.
These restrictions do not apply to closing the valves by
				external methods.
TABLE A-11
Minimum Metal Thickness of Bodies of Cast-Iron
				Malleable-Iron and Bronze Screwed Fittings (The following table is taken from
				ASA B16d-1941, B16c-1939, MSS SP-11-1944, B16-15-1947 and MSS
				SP-31-1931.)
Body metal thickness, inches
Cast-iron screwed fittings
Nominal pipe size, inches
125 pounds
250 pounds
150 pounds
300 pounds
125 pounds
250 pounds
1/2
. . .
. . .
0.090
. . .
0.08
. . .
1/4
0.110
0.18
0.095
0.14
0.08
0.11
3/8
0.120
0.18
0.100
0.15
0.09
0.12
1/2
0.130
0.20
0.105
0.16
0.09
0.13
3/4
0.155
0.23
0.120
0.18
0.10
0.16
1
0.170
0.28
0.134
0.20
0.11
0.17
11/4
0.185
0.33
0.145
0.22
0.12
0.19
11/2
0.200
0.35
0.155
0.24
0.13
0.20
2
0.220
0.39
0.173
0.26
0.15
0.22
21/2
0.240
0.43
0.210
0.31
0.17
0.24
3
0.260
0.48
0.231
0.35
0.19
0.26
31/2
0.280
0.52
0.248
. . .
. . .
. . .
4
0.310
0.56
0.265
. . .
0.22
0.31
5
0.380
0.66
0.300
. . .
6
0.430
0.74
0.336
. . .
8
0.550
0.90
. . .
. . .
10
0.690
1.08
. . .
. . .
12
0.800
1.24
. . .
. . .
All pressures are in pounds per square inch (gage).
SECTION 5
FUSIBLE PLUGS
A-19
(a) Fire-actuated fusible plugs, if used,
				except as provided in paragraph A-20(i), shall be filled with tin of the
				following composition, having a melting point between 445 and 450 degrees
				Fahrenheit.
Pure tin, minimum, percent .......
99.3
Copper, maximum, percent .......
0.5
Lead, maximum, percent .......
0.1
Total impurities, percent .......
0.7
(b) The fusible metal shall extend from the water end of the
				plug to the point of least diameter of the hole and shall be carefully alloyed
				to the casing. A test shall be made to determine that the fusible metal is not
				loose in the plug.
(c) Fusible plugs shall be renewed at least once each year.
				Casings which have been used shall not be refilled.
(d) Fusible plugs filled with tin as specified in (a) shall not
				be used for pressures and temperatures which will cause the plug to fail while
				it is submerged in the boiler water.
TABLE A-12
Numbers for Ring-Joint Gaskets and Grooves
Number
Pitch diameter
							 P
Width of ring
							 A
R 11
111/32
×
1/4
R 12
19/16
×
5/16
R 13
111/16
×
5/16
R 14
13/4
×
5/16
R 15
17/8
×
5/16
R 16
2
×
5/16
R 17
21/4
×
5/16
R 18
23/8
×
5/16
R 19
29/16
×
5/16
R 20
211/16
×
5/16
R 21
227/32
×
7/16
R 22
31/4
×
5/16
R 23
31/4
×
7/16
R 24
33/4
×
7/16
R 25
4
×
5/16
R 26
4
×
7/16
R 27
41/4
×
7/16
R 28*
43/8
×
1/2
R 29
41/2
×
5/16
R 30
45/8
×
7/16
R 31
47/8
×
7/16
R 32*
5
×
1/2
R 33
53/16
×
5/16
R 34
53/16
×
7/16
R 35
53/8
×
7/16
R 36
57/8
×
5/16
R 37
57/8
×
7/16
R 38*
63/16
×
5/8
R 39
63/8
×
7/16
R 40
63/4
×
5/16
R 41
71/8
×
7/16
R 42*
71/2
×
3/4
R 43
75/8
×
5/16
R 44
75/8
×
7/16
R 45
85/16
×
7/16
R 46*
85/16
×
1/2
R 47*
9
×
3/4
R 48
93/4
×
5/16
R 49
105/8
×
7/16
R 50*
105/8
×
5/8
R 51*
11
×
7/8
R 52
12
×
5/16
R 53
123/4
×
7/16
R 54*
123/4
×
5/8
R 55*
131/2
×
11/8
R 56
15
×
5/16
R 57
15
×
7/16
R 58*
15
×
7/8
R 59
155/8
×
5/16
R 60*
16
×
11/4
R 61
161/2
×
7/16
R 62*
161/2
×
5/8
R 63*
161/2
×
1
R 64
177/8
×
5/16
R 65
181/2
×
7/16
R 66*
181/2
×
5/8
R 67*
181/2
×
11/8
R 68
203/8
×
5/16
R 69
21
×
7/16
R 70*
21
×
3/4
R 71*
21
×
11/8
R 72
22
×
5/16
R 73*
23
×
1/2
R 74*
23
×
3/4
R 75*
23
×
11/4
R 76
261/2
×
5/16
R 77*
271/4
×
5/8
R 78*
271/4
×
1
R 79*
271/4
×
13/8
All dimensions given in inches.
The edge of each flange and the outside circumference of each
				ring shall carry corresponding identification marks,
i.e.,
R11, R45, etc.
*When ordering rings for nominal pipe sizes which may have
				either oval or octagonal shaped rings, purchasers must specify oval or
				octagonal shaped rings as desired.
(e) The fusible metal may be partly replaced by a bronze plug
				loosely fitted to the hole and of such size that it will pass freely through
				the hole on the fire side, from which side it must be inserted into the casing.
				Such plug shall be properly alloyed to the casing with the same fusible metal
				as required by (a).
A-20
(a) Waterside plugs are fusible plugs which
				are inserted from the water side of the plate, flue, or tube to which they are
				attached. Fireside plugs are fusible plugs inserted from the fire side of the
				plate, flue, or tube to which they are attached.
(b) The casing of the fusible plugs shall be made of
				composition conforming to specification SB-61.
(c) Typical designs of fusible plugs are given in Figure
				A-10.
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(d) The bore of the casing shall be tapered continuously from
				the water end of the casing for a distance of at least one inch to a diameter
				of not less than three-eighths inch at a point not less than one-half inch from
				the fire end. The diameter of the bore at either end shall be not less than
				one-half inch. The hole on the fire end shall be as large as possible and may
				be of any shape provided the cross-sectional area at all points is greater than
				the area of the least cross section of the fusible metal.
(e) A fusible plug shall be of such length that when installed
				it shall project at least three-quarters inch on the water side of the plate,
				tube, or flue. It shall extend through the plate, tube, or flue on the fire
				side as little as possible but not more than one inch.
(f) A fireside plug may be designed so as to be inserted by
				means of a plug-type wrench, so as to reduce the projection on the fire
				side.
(g) If a fire-actuated fusible plug is inserted in a tube, the
				tube wall shall be not less than 0.22 inch thick, or sufficient to give four
				full threads.
(h) Fusible plugs which comply with the requirements of
				paragraphs A-19 and A-20 must be stamped on the casing with the name of the
				manufacturer, and on the water end of the fusible metal, "ASME Std." Fusible
				plugs which comply with the rules and regulations of the U. S. Bureau of Marine
				Inspection and Navigation (now under the U. S. Coast Guard) will be considered
				to comply with the requirements of paragraphs A-19 and A-20 and may have the
				letters "ASME" stamped on the casing instead of on the fusible metal.
(i) Fusible metal, other than tin as specified in paragraph
				A-19(a), for use under temperatures exceeding 450 degrees Fahrenheit, may be
				used and the casing may be made of other material and shape than specified in
				paragraph A-20(b), (c), and (d) if the metal and the casing are approved by the
				administrative authority. Such plugs shall not be marked as "ASME Std."
A-21
Fire-actuated fusible plugs, if used, shall
				be located at the lowest permissible water level for different types of boilers
				as given below; steam-actuated plugs, if used, shall be so located that they
				will operate when the water level is at the point where a fire-actuated fusible
				plug would be located if installed under these rules.
(a)
Horizontal-return tubular boilers
-in the
				rear head, not less than one inch above the upper rows of tubes, the
				measurement to be taken from the line of upper surface of tubes to the center
				of the plug, and projecting through the sheet not less than one inch. When the
				distance between the uppermost line of tubes and the top of the steam space is
				13 inches or less, the fusible plug may be at a lesser distance than one inch
				above the upper row of tubes, but in no case shall the bottom of the plug be
				located below the level of the top of the uppermost row of tubes.
(b)
Horizontal flue boilers
-in the rear head,
				on a line with the highest part of the boiler exposed to the products of
				combustion, and projecting through the sheet not less than one inch.
(c)
Traction, portable, or stationary boilers of the
				locomotive type or boilers having water-tube elements and crown sheets
-in the highest part of the crown sheet, and projecting through the sheet not
				less than one inch.
(d)
Vertical fire-tube boilers (standard type)
-in an outside tube, not less than one third the length of the tube above the
				lower tube sheet.
(e)
Vertical fire-tube boilers (submerged-tube
				type)
-in the upper tube sheet and projecting through the sheet not
				less than one inch.
(f)
Water-tube boilers with straight tubes, box, or
				sectional headers and longitudinal or cross-horizontal drums
-in the
				water and steam drum not less than six inches above the bottom of the drum,
				over the first pass of the products of combustion, and projecting through the
				sheet not less than one inch.
(g)
Water-tube boilers of the bent-tube type
-in the front water and steam drum, not less than six inches above the bottom
				of the drum, exposed to the products of combustion, and projecting through the
				sheet not less than one inch.
(h)
Vertical water-tube boilers
-in the shell
				of the top drum and not less than six inches above the upper tube sheet, and
				projecting through the sheet not less than one inch; so located as to be at the
				front of the boiler and exposed to the first pass of the products of
				combustion.
(i)
Scotch marine-type boilers
-in the
				combustion chamber top, and projecting through the sheet not less than one
				inch.
(j)
Dry-back Scotch-type boilers
-in the rear
				head, not less than two inches above the upper row of tubes, and projecting
				through the sheet not less than one inch. When the distance between the
				uppermost line of tubes and the top of the steam space is 13 inches or less,
				the bottom of the fusible plug may come at a lesser distance than two inches
				above the upper row of tubes; but in no case shall the plug be located below
				the level of the top of the uppermost row of tubes.
(k)
Fire-tube boilers of the refractory-lined firebox
				type
-in the rear head not less than two inches above the upper row of
				tubes. When the distance between the uppermost row of tubes and the top of the
				steam space is 13 inches or less, the bottom of the fusible plug may come at a
				lesser distance than two inches above the upper row of tubes but in no case
				shall the plug be located below the level of the top of the uppermost row of
				tubes.
(l) Fire-engine boilers are not usually supplied with fusible
				plugs. Unless special provision is made to keep the water above the firebox
				crown sheet other than by natural level, the lowest permissible water level
				shall be at least three inches above the top of the firebox crown sheet.
(m) For other types and new designs, fusible plugs shall be
				placed at the lowest permissible water level, subject to the direct radiant
				heat of the fire or in the direct path of the products of combustion, as near
				the primary combustion chamber as possible.
SECTION 6
STANDARD PRACTICE FOR MAKING HYDROSTATIC TESTS ON A
				BOILER PRESSURE PART
A-22 Scope.
This method of test is applicable only
				to materials having a definite proportional or elastic limit such as most
				carbon and alloy steels. It is not applicable to materials with indefinite or
				indeterminate proportional limits such as cast iron and most nonferrous
				materials. *The principle upon which the test is
				based assumes that the most highly stressed point in the pressure part will be
				subjected to a permanent set when the stress at this location reaches the
				proportional or elastic limit of the material. Since the stress will be
				directly proportional to the hydrostatic pressure, the determination of the
				pressure which stresses the weakest point to the proportional limit will permit
				a calculation of the maximum allowable working pressure that will result in a
				safe working stress in accordance with requirements of Part 14 for the material
				from which the part is made at the maximum operating temperature.
A-23 Material.
The structure shall be made from
				material approved for its intended use by the New York State Boiler Code [Part
				14].
A-24 Workmanship.
The dimensions and minimum
				thickness of the structure to be tested should not vary materially from those
				actually used. If possible, the structure to be tested should be selected at
				random from a quantity of such intended for use.
A-25 Preparation for test.
(a) It is necessary to
				test only the weakest point of the structure but several points should be
				checked to make certain that the weakest one is included. The less definite the
				location of the weakest point, the more points should be checked.
(b) The movement of the reference points may be measured with
				reference to a fixed surface, or two reference points may be located on
				opposite sides of a symmetrical structure and the total deformation between
				those two points measured.
(c) Indicating micrometer gages accurate to 0.001 inch are most
				suitable for measuring deformation of the structure at the reference points
				although any form of accurate micrometer may be used.
(d) A hand test pump is satisfactory as a source of hydrostatic
				pressure. Either a test gage or a reliable gage which has been calibrated with
				a test gage should be attached to the structure.
(e) The maximum hydrostatic pressure that must be provided for
				will vary from two to three times the expected maximum allowable working
				pressure for carbon-steel structures.
(f) The location of the weakest point of the structure may be
				determined by applying a thin coating of plaster of Paris or similar material,
				and noting where the surface coating starts to break off under hydrostatic
				test. The coating should be allowed to dry before the test is started.
A-26 Hydrostatic test.
(a) The first application
				of hydrostatic pressure need not be less than the expected maximum allowable
				working pressure. At least 10 separate applications of pressure, in
				approximately equal increments, should be made between the initial test
				pressure and the final test pressure.
(b) When each increment of pressure has been applied the valve
				between the pump and the structure should be closed and the pressure gage
				watched to see that the pressure is maintained and no leakage occurs. The total
				deformation at the reference points should be measured and recorded and the
				hydrostatic pressure recorded. The pressure should then be released and each
				point checked for any permanent deformation which should be recorded.
(c) Only one application of each increment of pressure is
				necessary.
(d) The pressure should be increased by substantially uniform
				increments, and readings taken until the elastic limit of the structure has
				obviously been exceeded.
(e) The pressure part shall not have been subjected to a
				pressure greater than the designed maximum allowable working pressure prior to
				making the proof hydrostatic test.
A-27 Physical characteristics of metal.
Determine
				the proportional limit of the material in accordance with A.S.T.M.
				specification E8-42, standard method of tension testing of metallic materials.
				It is important that this be determined from a number of specimens cut from the
				part tested, after the test is completed, in order to insure that the average
				proportional limit of the material in the part tested is used to calculate the
				safe working pressure. The specimens should be cut from a location where the
				stress during the test has not exceeded the proportional limit, so that the
				specimens will be representative of the material as tested. These specimens
				should not be cut with a gas torch as there is danger of changing the
				proportional limit of the material.
A-28 Plotting curves.
A single cross-section sheet
				should be used for each reference point of the structure. A scale of one inch
				equals 0.01 inch deformation, and a scale of at least one inch equals the
				approximate test pressure increments has been found satisfactory. Plot two
				curves for each reference point, one showing total deformation under pressure
				and one showing permanent deformation when the pressure is removed.
A-29 Determining proportional limit of pressure
				part.
(a) Locate the proportional limit on each curve of total
				deformation as the point at which the total deformation ceases to be
				proportional directly to the hydrostatic pressure. Draw a straight line that
				will pass through the average of the points that lie approximately in a
				straight line. The proportional limit will occur at the value of hydrostatic
				pressure where the average curve through the points deviates from this straight
				line.
(b) In pressure parts such as headers, where a series of
				similar weak points occur, the average hydrostatic pressure corresponding to
				the proportional limits of the similar points may be used
(c) The proportional limit obtained from the curve of total
				deformation may be checked from the curve of permanent deformation by locating
				the point where the permanent deformation begins to increase regularly with
				further increases in pressure. Permanent deformations of a low order that occur
				prior to the point really corresponding to the proportional limit of the
				structure, resulting from the equalization of stresses and irregularities in
				the material, may be disregarded.
(d) It should be made certain that the curves show the
				deformation of the structure and not slip or displacement of reference
				surfaces, gages, or the structure.
A-30 Determining maximum allowable working
				pressure.
(a) Having determined the proportional limit of the weakest
				point of the structure, the corresponding maximum allowable working pressure
				may be determined by the formula:
P
=
H S..
E
.......
where
P
= maximum allowable working pressure,
				pounds per square inch,
H
= hydrostatic pressure at the proportional
				limit of the pressure part, pounds per square inch,
S
= working stress permitted by Tables P-5,
				P-6, or P-7 for the material at the maximum operating temperature as determined
				by requirements of Part 14,
E
= average proportional limit of material,
				pounds per square inch.
(b) For carbon-steel material, complying with a specification
				of Part 14 and with a minimum tensile strength not over 62,000 psi, the
				proportional limit may be assumed to be two fifths of the average tensile
				strength of the specified range. Where no range is specified, the average
				tensile strength may be assumed as 5000 psi greater than the minimum. This will
				eliminate the necessity for cutting tensile specimens and determining the
				actual proportional limit. Under such conditions, the material in the pressure
				part tested should have had no appreciable cold working or other treatment that
				would tend to raise the proportional limit above the normal value. The pressure
				part should preferably be normalized after forging or forming.
A-31 Retests.
A retest should be allowed on an
				additional structure if errors or irregularities are obvious in the
				results.
A-32 Testing parts made from material without definite
				proportional limit.
(a) Pressure parts made from cast iron or nonferrous
				materials without a well-defined proportional limit must be tested until
				failure occurs by rupture. The hydrostatic pressure at which rupture occurs
				must be determined. If excessive leakage occurs at rolled joints or at gasketed
				handhole fittings, they may be seal-welded for the test to permit test to
				destruction, provided the welding does not materially increase the strength of
				the part. No deflection measurements will be necessary. The average actual
				tensile strength of the material from which the part tested is made must be
				determined from test specimens cut from the part tested. If this is not
				practicable, the tensile strength must be assumed to be the maximum of the
				range given in the specifications for the material.
(b) The maximum allowable working pressure may be determined by
				the formula:
P
=
H S..
E
.......
where
P
equals; maximum allowable working
				pressure, pounds per square inch,
H
= hydrostatic pressure at time of rupture,
				pounds per square inch,
S
= working stress permitted by Tables P-5,
				P-6, or P-7 for the material at the maximum operating temperature as determined
				by requirements of Part 14,
E
= average actual tensile strength from test
				specimens, or maximum of the range in specification, pounds per square
				inch.
(c) It is possible that certain designs of pressure parts may
				result in concentrated stresses at critical points which may be relieved by
				yielding of the material at these points prior to rupture, so that failure may
				occur at some other point and not indicate the point of maximum stress at
				pressures below that causing rupture. There may be conditions which would make
				a test to destruction impracticable. Under such conditions a special test may
				be made from a carbon steel material of the same dimensions and thickness as
				used for the material in question. This special test part can then be tested in
				accordance with paragraphs A-23 to A-32. The maximum allowable working pressure
				for the part made from the material in question would be determined by using
				the proper value of
S
for the material in the formula in
				paragraph A-30. The value of
E
used in the formula would be
				that for the carbon steel material from which the special test part is
				made.
Note:
Paragraphs A-33 to A-64 inclusive are
				incorporated in sections
				14-12.1 to
				14-12.29, inclusive.
SECTION 7
EXAMPLES OF METHODS OF COMPUTATION OF OPENINGS IN
				SHELLS
Note:
Applications of the rules in section
				14-11.170 are given in the
				following examples.
A-65
A boiler shell for 275 psi working pressure
				has an inside diameter of 36 inches and is made of one-half inch thick plate
				having a minimum ultimate tensile strength of 55,000 psi. Is it permissible to
				use a two-inch pipe connection by tapping a hole for the pipe directly into the
				shell?
K
=
PD
=
275 ×
				37
= 0.925 or 92.5 per cent
2St
2 × 11,000 × 0.50
				.......
Dt
= 37 × 0.5 = 18.5
From the chart in Figure P-34, the maximum allowable diameter
				of an unreinforced opening is
d
= 3.05 inches.
The two-inch tapped hole has a diameter of 2.375 inches and
				according to Table P-12 requires at least 0.435 inches thickness for threads.
				Also, although the working pressure is above 100 psi, the size of the threaded
				connection is not greater than the maximum of three-inch pipe size permitted
				when this pressure is exceeded. Therefore the connection meets the requirements
				of Part 14.
A-66
A special forging (such as shown in Figure
				A-11[a]) for a three and one-half inch pipe connection is inserted in a boiler
				shell the working pressure of which is 100 psi. The length of thread is two
				inches, the outside diameter of the portion projecting through the shell is
				four and three-quarters inches, and the cross-sectional area of the forging is
				2.25 square inches. This construction complies with the rule that a threaded
				connection over three-inch pipe size shall be used only for working pressures
				of 100 psi and under. The length of thread is sufficient, as indicated by Table
				P-12.
Click
				to view image
(a)
Seal welded.
If seal welding only is
				applied to the forging, the opening is classed as an unreinforced hole having
				in this case a diameter of four and three-quarters inches. The rules in
				subdivision (a) of section
				14-11.170 govern in this case.
				Assume the following data: inside diameter of shell = 48 inches; thickness =
				1/2 inch; working pressure 100 psi; material is grade A of specification SA-285
				(45,000 psi minimum ultimate tensile strength).
K
=
PD
=
100 ×
				49
= 0.545 or 54.5 per cent
2St
2 × 9000 × 0.50
				.......
Dt
= 49 × 0.50 = 24.5
From Figure P-34,
d
= 6.15 inches. The actual
				diameter is four and three-quarters inches, and therefore this construction
				meets the requirements of Part 14.
(b)
Strength welded.
If the outside diameter
				of the neck of the forging (in this case four and three-quarters inches) is
				greater than d as given by the charts in Figure P-34, the welds must be strong
				enough to develop a minimum required amount of strength (strength welding). The
				rules in subdivisions (e) to (h) of section
				14-11.170 govern in this case.
				Assume: inside diameter, thickness, working pressure, and material of shell
				same as in (a); working temperature = 850 F;
S
= 5700 psi (see
				Table P-7).
K
=
100 × 49
= 0.86 or 86 per
				cent ... 2 × 5700 × 0.50 .......
Dt
= 49 × 0.50 = 24.5
From Figure P-35,
d
= 4.12 inches. As the
				outside diameter of the neck of the forging (or hole in the shell) is four and
				three-quarters inches, the forging must be strength welded to the shell and the
				design must comply with subdivisions (e) to (h) of section
				14-11.170.
(1) Assume a fillet weld on the outside with
				15/16 inch legs. The weld
				dimensions then comply with detail 3 of Figure P-36. Since the forging is
				rigidly welded to the shell, the diameter of the opening is now four inches and
				the limits therefore are as shown in Figure A-11(a).
Cross section through shell = 0.50 × (8 - 4.75) = 1.62 sq in.
				Cross section through forging = (1
				15/16
								× 0.70) + (1.50 × 0.5)
				= 2.20 sq in. Cross section through weld = 2 × 1/2 × 0.9375 × 0.9375 =
0.88 sq in.
.......
Total actual cross section. 4.70 sq in. .......
The required thickness when
E
= 0.90 (see §
								14-11.61) is
t
=
PR
=
100 ×
				24
= 0.468 inches...
SE
5700 × 0.90 .......
Required cross section = area (
EFGH
+
JKLM
) = 0.468 × (8 2) = 2.810 square inches.
Therefore paragraph (1) of subdivision (g) of section
				14-11.170 has been complied
				with.
(2) The fillet weld can fail in tension, around the
				circumference of the four and three-quarters inches diameter, or it can fail in
				shear around the circumference of the mean diameter of
				511/16 inches. The strength
				of that part of the weld on one side of the center line (on a semicircle) must
				be at least equal to that specified in paragraph (2) of subdivision (g) of
				section 14-11.170, and in subdivision (h)
				of section
				14-11.170. The allowable working
				stress of the weld in shear is 0.8 times the allowable working stress in
				tension.
Strength of weld in tension = 0.9375 × 1/2 × (3.14 × 4.75) ×
				(0.9 × 5700) = 35,900 pounds.
Strength of weld in shear = 0.9375 × 1/2 × (3.14 × 5.6875) ×
				(0.8 × 0.9 × 5700) = 34,300 pounds.
The weld is weaker in shear.
Strength of forging = 2.25 × 5700 = 12,800 pounds.
Strength of cross section represented by (
QFGR
+
JSTM
) = 0.468 × (4 - 2) × 5700 = 5330 pounds.
Therefore paragraph (2) of subdivision (g), and subdivision (h)
				of section
				14-11.170 have been complied
				with.
A-67
A studded connection such as shown in Figure
				A-11(b) is for six-inch: 400-pound American Standard seamless pipe. The data
				for the shell are as follows: inside diameter = 60 inches; thickness = 2
				1/8 inches; working pressure
				= 325 psi; working temperature below 650 F; material grade B of specification
				SA-285. The fiat for the raised face reduces the shell thickness to 1
				9/16 inches, at the edge of
				the opening.
K
=
325 × 64.25
= 0.670 or 67
				per cent.. 2 × 10,000 × 1.5625 .......
Dt
= 64.25 × 1.5625 = 100.4
From Figure P-34,
d
= 8 inches. The actual
				equivalent diameter is the diameter of the hole in the shell plus the diameters
				of two stud holes, or 6.049 + (2 × 0.875) = 7.799 inches. Therefore the
				connection meets the requirements of Part 14. This example is for a shell built
				to stresses permitted by Figure P-7. For fusion-welded or seamless construction
				where design stresses exceed those given in Table P-7 as permitted under
				subdivision (c) of section
				14-11.61, subdivision (l) of
				section 14-11.85 and subdivision (a) of
				section 14-11.90, this example will have a
				different value of
S
and
K
but the procedure
				of calculation will be similar.
A-68
(a) A four-inch extra heavy pipe is welded
				into a shell as shown in Figure A-11(c). The shell has an inside diameter of 30
				inches, a thickness of three-eighths inch, and a working pressure of 200 psi.
				The material is in accordance with specification SA-285. The weld, as shown in
				Figure A-11(c), complies with detail 4 of Figure P-36.
Cross section I = 0.375 (7.652 - 4.50) = 1.181 sq in.
				.......
Cross section II = 0.337 × 1.217 × 2 = 0.820 sq in.
				.......
Cross section III = 2 × 1/2 × 0.50 × 0.50 =
0.250 sq
				in
.......
Total actual cross section = 2.251 sq in.
The required thickness when
E
= 0.90 is
t
=
200 × 15
= 0.303 inch.
				11,000 × 0.90 .......
Required cross section = 0.303 × (7.652 - 2) = 1.71 square
				inches.
Therefore paragraph (1) of subdivision (g) of section
				14-11.170 has been complied
				with.
(b) The weld can fail in tension by tearing around its
				circumference on a diameter of five and one-half inches. Since welding
				equivalent to that required under the rules in section
				14-11.40 to
				14-11.49 has been used, the
				allowable stress in tension is 11,000 × 0.90 or 9900 psi (see §
								14-11.41).
Strength of weld in tension = 0.375 × 1/2 × 3.14 × 5.50 × 9900
				= 32,100 pounds.
The attachment of the nozzle can also fail by shearing through
				the weld and the nozzle neck (along the line
NP
in Figure
				A-11[c]), around the circumference of the mean diameter of (5.50 + 3.826) × 1/2
				= 4.663 inches. The allowable working stress of the weld in shear is 0.8 times
				the allowable working stress in tension.
Strength of attachment in shear = (0.50 + 0.37) × 1/2 × 3.14 ×
				4.663 × (0.8 × 9900) = 48,600 pounds.
From the above, the construction is weaker in tension than in
				shear.
Strength of nozzle = (Area II) × S = 0.820 × 11,000 = 9020
				pounds.
Strength of cross section represented by (
QFGR
+
JSTM
) = 0.303 × (3.826 - 2) × 11,000 = 6090 pounds.
Therefore paragraph (2) of subdivision (g) of section
				14-11.170 has been complied
				with.
Strength of attachment in shear = (0.50 + 0.337) × 1/2 × 3.14 ×
				4.663 × (0.8 × 7000) = 34,400 pounds.
From the above, the construction is weaker in tension than in
				shear.
A-69
(a) A 16-inch welded circular nozzle-type
				manhole is located on a seamless shell (grade 1, specification SA-266), as
				shown in Figure A-11(d). The shell data are as follows: inside diameter = 96
				inches; thickness = 2 inches; working pressure = 500 psi; working temperature =
				600 F. Welding suitable for power boilers is used.
(1) The welds at the manhole neck comply with detail 1 and the
				welds on the reinforced pad with details 5 and 6 of Figure P-36.
Cross section I = 2 × (32 - 18) = 28.00 sq in. .......
Cross section II = 1.00 × 5.25 × 2 = 10.50 sq in.
				.......
Cross section III = 2.5 × (32 - 21.5) = 26.25 sq in.
				.......
Cross section IV = two 3/4 -in. fillets + one 1-in. fillet =
2.12 sq in.
.......
Total actual cross section = 66.87 sq in.
The required thickness when E = 0.90 is
t
=
500 × 48
= 2.222 inches.
				12,000 × 0.90 .......
Required cross section = 2.222 × (32 - 2) = 66.66 square
				inches.
Therefore the design meets the requirements of paragraph (1) of
				subdivision (g) of section
				14-11.170.
(2) Welding of the manhole neck:
Strength of welds in tension = (2 × 0.75) × 1/2 × 3.14 × 18 ×
				(0.9 × 12,000) = 458,000 pounds.
Strength of welds in shear = (2 × 0.75) × 1/2 × 3.14 × 18.75 ×
				(0.8 × 0.9 × 12,000) = 381,000 pounds.
The welds at the manhole neck are weaker in shear.
Strength of neck = (Area II) ×
S
= 10.50 ×
				12,000 = 126,000 pounds.
Strength of cross section represented by (
QFGR
+
JSTM
) = 2.222 × (16 2) × 12,000 = 373,000 pounds.
Therefore the welding of the neck meets the requirements of
				paragraph (2) of subdivision (g) of section
				14-11.170.
(3) Welding of the reinforcing pad:
Strength of welds in tension = [(1.00 × 1/2 × 3.14 × 21.5) +
				(0.625 × 1/2 × 3.14 × 36)] × (0.9 × 12,000) = 746,000 pounds.
Strength of welds in shear = [(1.00 × 1/2 × 3.14 × 20.5) +
				(0.625 × 1/2 × 3.14 × 36.635)] × (0.8 × 0.9 × 12,000) = 589,000 pounds.
The welds at the reinforcing pad are weaker in shear.
Strength of reinforcing pad = 2.5 × (32 21.5) × 12,000 =
				315,000 pounds.
Strength of cross section represented by (
QFGR
+
JSTM
) = 373,000 pounds, as above.
Therefore the welding of the reinforcing pad meets the
				requirements of paragraph (2) of subdivision (g) of section
				14-11.170.
The above design corresponds to type H shown in Figure P-36.
				For other types of construction employing reinforcing pads, such as types F, G,
				J, and others, the methods of calculation are similar to the above.
(b) This example is for a shell built to stresses permitted by
				Figure P-7. For fusion-welded or seamless construction where design stresses
				exceed those given in Table P-7 as permitted under subdivision (c) of section
				14-11.61, subdivision (l) of
				section 14-11.85 and subdivision (a) of
				section 14-11.90, this example will have a
				different value of
S
and
K
but the procedure
				of calculation will be similar.
A-70
An eight-inch riveted nozzle is located on a
				drum as shown in Figure A-11(e). The shell data are as follows: inside diameter
				= 54 inches; thickness = 1 1/4 inches; working pressure = 350 psi; working
				temperature = 440 F; minimum tensile strength = 55,000 psi.
Assume the nozzle to be 8 inches inside diameter, the thickness
				of the nozzle neck to be 9/16
				inch, the thickness of the riveting flange to be 3/4 inch, and the outside
				diameter of the riveting flange to be 17 1/4 inches.
Assume also 18 1 1/4-inch rivets on a 14-inch rivet circle with
				one 9/32-inch rivet holes
				straddling the longitudinal center line through the nozzle; minimum tensile
				strength = 55,000 psi. The opening in the shell is 83/4 inches to provide space
				for calking.
The weakest section will be along a line parallel to the
				longitudinal axis passing through the centers of the two rivets nearest the
				center line of the nozzle as shown in Figure A-11(e).
The neck of the nozzle may be considered as reinforcement for a
				distance of two and one-half times its thickness measured from the back of the
				riveting flange. Therefore the distance of line AB (see Figure A-11[e]) from
				the outside of the shell equals1; (2.5 × 0.5625) + 0.75 = 2.16 inches.
Cross section I = 17.5 - (8.41 + 1.282 + 1.282) × 1.25 = 8.16
				sq. in. .......
Cross section II = (2.16 × 2 × 0.59) + [17.07 - (7.62 + 0.59 +
				0.59 + 1.282 + 1.282)] × 0.75 = 2.55 + 4.28 =
6.83 sq
				in.
Total actual cross section = 14.99 sq in.
The required thickness when E = 0.90 is
t
=
350 × 27
= 0.955 inches..
				11,000 × 0.90 .......
Required cross section = 0.955 × (17.5 2) = 14.81 square
				inches.
Therefore the design meets the requirements of paragraph (1) of
				subdivision (g) of section
				14-11.170.
Failure can occur by shearing of the rivets on one side of
				section AA. The ultimate strength of the rivets in shear is 44,000 psi.
Area of rivets to one side of section = 0.7854 × 1.282 × 1.282
				× 7 = 9.05 square inches.
Ultimate strength of rivets in shear = 9.05 × 44,000 = 398,000
				pounds.
Ultimate strength of nozzle = (Area II)× X U.T.S. = 6.83 ×
				55,000 = 376,000 pounds.
Ultimate strength of cross section represented by (QFGR + JSTM)
				= 0.955 × (8.41-2) × 55,000 = 336,000 pounds.
Therefore the riveting meets the requirements of paragraph (2)
				of subdivision (g) of section
				14-11.170.
Failure can also occur by the internal pressure blowing the
				nozzle off the shell.
The ultimate strength of the rivets in tension is 55,000
				psi.
Total area of rivets = 0.7854 × 1.282 × 1.282 × 18 = 23.3
				square inches.
Ultimate strength of rivets in tension = 23.3 × 55,000 =
				1,282,000 pounds.
Required strength due to internal pressure acting on 8 3/4-inch
				calking circle with factor of safety of 5 = 0.7854 × 8.75 × 8.75 × 350 × 5 =
				105,400 pounds.
If the riveting flange is calked also on the outside, then the
				required strength due to internal pressure acting on 17 1/4-inch calking
				circle, with factor of safety of 5 = 0.7854 × 17.25 × 17.25 × 350 × 5 = 410,000
				pounds.
Therefore the riveting meets the requirements of paragraphs (1)
				and (2) of subdivision (j) of section
				14-11.170.
The shell plate may fail by tearing around through the rivet
				holes. Checking by applying the rules in subdivision (b) of section
				14-11.76:
Click
				to view image
Therefore the design meets the requirements of subdivision (b)
				of section
				14-11.76.
This example is for a shell built to stresses permitted by
				Figure P-7. For fusion-welded or seamless construction where design stresses
				exceed those given in Table P-7 as permitted under subdivision (c) of section
				14-11.61,
				P-185(l)* and subdivision (a) of section
				14-11.90, this example will have a
				different value of 8 and K but the procedure of calculation will be
				similar.
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				to view image
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				to view image
SECTION 9
APPROVAL OF NEW MATERIALS UNDER THE BOILER CONSTRUCTION
				CODE
A-75
If possible, the material should be
				identified with an A.S.T.M. specification or tentative specification. If the
				material varies only slightly from an A.S.T.M. specification by the addition,
				say, of a small amount of alloying element, it should be stated that the
				material will comply with some specification except as noted and the exception
				should be stated not only as to chemical composition, but as to physical
				properties and test results.
A-76
If no A.S.T.M. specification can be applied,
				the following information should be given in the same form as used by the
				A.S.T.M.:
(a) Chemical composition, including for ferrous materials,
				carbon, manganese, phosphorus, sulphur, and silicon, together with alloying
				elements, if any.
(b) Tensile properties, over the temperature range of
				contemplated service. Where the vessels are to be stress-relieved or
				heat-treated, the tensile tests shall be made after the specimens are similarly
				treated.
(c) Creep strength over any temperature range of contemplated
				service within which the phenomena of creep will lower the working strength of
				the material.
In both (a) and (b) the range rather than an exact
				determination of the properties should be given within which it is commercially
				practicable to reproduce the material.
A-77
If any heat treatment is required to produce
				the tensile properties, it should be stated.
A-78
The Brinell or Rockwell hardness should be
				given unless the information is well known for the material in question. This
				information is particularly advantageous if the hardness is higher than for the
				particular materials specified for boiler pressure parts.
A-79
If the material is to be used at low
				temperatures, below 0 Fahrenheit, the impact strength at these low temperatures
				should be given.
A-80
It is very important to know whether a new
				material is subject to critical conditions at temperatures within the range of
				use or fabrication. By critical conditions is meant a material change in
				brittleness, hardness, ductility, grain size, etc.
A-81
It should also be stated if the material is
				subject to age hardening or critical structural changes by a combination of
				physical and temperature conditions, such, for example, as the age hardening of
				certain aluminum alloys after cold working and subsequent heat treatment. This
				is particularly important in conditions which might occur during fabrication
				that result in this critical condition.
A-82
Unless the material is well known and not
				unusual in its characteristics, the coefficient of thermal expansion over the
				range of temperature within which the material will be used should be given,
				particularly if there is any marked variation from that of ordinary carbon
				steel.
A-83
It should be stated whether the material is
				commercially available and can be purchased within the specified range of
				chemical and physical qualities. If the material is covered by patents so that
				it cannot be manufactured by anyone who wishes to use it without securing a
				license or paying royalties, it should be so stated.
A-84
If the material is to be welded it should be
				stated whether any special procedure is required for electric fusion or gas
				welding and the amount of experience available for determining the weldability.
				It should be stated whether the material is subject to air hardening during
				welding. If special procedure must be followed in fusion welding the material,
				or if the vessel is stress-relieved or heat-treated after welding, the method
				should be specified, including the proper temperatures. As a check on
				weldability, it is recommended that the tests described in Subpart 14-15 be
				made, unless equivalent information is available.
A-85
Tests, results of which are submitted to the
				Board of Standards and Appeals, should be made upon the thickest plates
				contemplated, except as otherwise dictated by A.S.T.M. standards.
SECTION 10
MAXIMUM ALLOWABLE WORKING PRESSURES-THICK
				SHELLS
A-125
Shells for internal pressure. When the
				thickness of the shell exceeds one half of the inside radius, the maximum
				allowable working pressure on the cylindrical shell of a boiler or drum shall
				be determined by the following formulas:
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				to view image
Footnotes
* For method of testing parts made from such materials, see
				paragraph A-32.
* So in original. Reference probably should be to present
				subdivision (l) of section
				14-11.85.
Explanatory of Subparts 14-11 and 14-12 and containing matter
				  which is not mandatory unless specially referred to in the sections
				  therein.