Page 1 of 5
TI-S13-25
CH Issue 11
SV73 Cast Iron Safety Valve
Cert. No. LRQ 0963008 ISO 9001
Description
The SV73 cast iron series valves are built in conformance to Section I and VIII of the ASME Boiler and Pressure Vessel Code. They are primarily intended for use on power boilers and unfired pressure vessels where ASME Section I and VIII stamped valves are required. Applications Protection of steam systems downstream of pressure regulating stations, on inlet to such equipment as air coils, heat exchangers and process vessels. Also for use on flash recovery vessels on condensate return systems to protect vessels. Air systems to protect accumulation vessels and air equipment from overpressurisation. Steam boilers and generators. Available types The SV73 is available with cast iron body and stainless steel trim in orifice sizes from 'J' to 'R'. It has an open bonnet and easing lever and is available with screwed or flanged connections. Certification A manufacturers' Typical Test Report is provided as standard for each valve which will include valve set and hydraulic test pressure. Also available on request is material certification in accordance with EN 10204 3.1. Standards and approvals Approved by National Board of Boiler and Pressure Vessel Inspectors to ASME Boiler and Pressure Vessel Code Sections I and VIII. Seat tightness is in accordance with ANSI/API STD 527-1992. If National Board 'V' or 'UV' stamp is required, then this must be specified at the time of ordering. Important note: SV73 safety valves are not marked and therefore not to be used within the EEA.
Sizes and end connections 1½" x 2½" to 3" x 4" 1½" x 2½" to 3" x 4" 3" x 4" to 6" x 8"
Inlet /outlet screwed female NPT. Inlet flanged ANSI class 250 RF, Outlet screwed female NPT. Inlet flanged ANSI class 250 RF, Outlet flanged ANSI class 125 FF.
Temperature °F
Pressure /temperature limits ��� ��� ���
A
C Steam saturation curve
��� ��� � ���
D �
���
��� ��� Pressure psi g
B
���
���
The product must not be used in this region. A - B Limit for valves with a flanged inlet. C - D Limit for valves with a screwed inlet. Body design conditions Maximum Set pressure range Minimum Temperature
Maximum
Screwed inlet Flanged inlet
Minimum ASME I
ANSI 250 250 psi g 5 psi g 406°F 446°F -20°F
Steam
3%
Overpressure
Steam 10% ASME VIII Air/gas 10% ASME I Steam 2 - 6% Performance data Blowdown limits Steam 7% ASME VIII Air /gas 7% Steam 0.955 Derated coefficient of discharge values Air /gas 0.955 Maximum permitted backpressure up to: 10% of set pressure Tested at a maximum inlet cold hydraulic test pressure of 600 psi g Local regulations may restrict the use of this product to below the conditions quoted. In the interests of development and improvement of the product, we reserve the right to change the specification without notice.
© Copyright 2007
Page 2 of 5 4 26 16
24, 25
14 15 20
18
6 3 10 12 13 11 27
40 9
5 7
21 17
23 8
22
2
1
Materials No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 20 21 22 23 24 25 26 27 40
Part Body Seat Bonnet Cap Disc Spring Upper adjusting ring Lower adjusting ring Stem (lower) Stem (upper) Spring washers (2 off) Bonnet stud Bonnet nut Adjusting screw Adjusting screw nut Release ring Lock-nut (2 off) Lever Cap set screw Upper adjusting ring pin Lower adjusting ring pin Disc ball Pin washer Lever pin Lock-nut Guide plate Stem pin
Material Cast iron Stainless steel Cast iron Cast iron Stainless steel Chrome-vanadium alloy steel Stainless steel Stainless steel Stainless steel Stainless steel Steel Steel Steel Stainless steel Carbon steel Carbon steel Carbon steel Grey iron Carbon steel Stainless steel Stainless steel Stainless steel Carbon steel Carbon steel Carbon steel Carbon steel Carbon steel
SV73 Cast Iron Safety Valve
ASTM A126 Class B ASTM A351 Grade CF8 ASTM A126 Class B ASTM A126 Class B ASTM A217 CA15 ASTM A351 Grade CF8 ASTM A351 Grade CF8 ASTM A479 Type 410 ASTM A479 Type 410 ASTM A105 ASTM A193 Grade B7 ASTM A194 Grade 2H ASTM A479 Type 410
TI-S13-25 CH Issue 11
Set pressure psi g
15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185 190 195 200 205 210 215 220 225 230 235 240 245 250
Steam saturation temperature ºF
250 259 267 274 281 287 292 298 303 307 312 316 320 324 328 331 335 338 341 344 347 350 353 356 358 361 363 366 368 371 373 375 377 380 382 384 386 388 390 392 394 396 398 399 401 403 404 406
1 833 2 146 2 459 2 772 3 085 3 398 3 711 4 025 4 338 4 651 4 964 5 277 5 590 5 903 6 216 6 529 6 842 7 155 7 469 7 782 8 293 8 408 8 721 9 034 9 347 9 660 9 973 10 286 10 599 10 913 11 226 11 539 11 852 12 165 12 478 12 791 13 104 13 417 13 728 14 043 14 354 14 670 14 980 15 296 15 606 15 922 16 232 16 548
lb/h 3%
1 897 2 231 2 566 2 900 3 234 3 569 3 903 4 237 4 572 4 906 5 240 5 575 5 909 6 244 6 578 6 912 7 247 7 581 7 915 8 250 8 584 8 918 9 253 9 587 9 922 10 256 10 590 10 925 11 259 11 593 11 928 12 262 12 597 12 931 13 265 13 600 13 934 14 268 14 600 14 937 15 269 15 606 15 937 16 275 16 606 16 943 17 275 17 612
lb/h 10%
Real flow
J
1.374
Orifice
Area Sq. In.
K
2 625 3 074 3 522 3 971 4 419 4 868 5 316 5 764 6 213 6 661 7 110 7 558 8 007 8 455 8 904 9 352 9 800 10 249 10 697 11 146 11 594 12 043 12 491 12 940 13 388 13 836 14 285 14 733 15 182 15 630 16 079 16 527 16 976 17 424 17 872 18 321 18 769 19 218 19 663 20 115 20 560 21 008 21 456 21 908 22 353 22 805 23 250 23 702
lb/h 3% 2 717 3 196 3 675 4 153 4 632 5 111 5 590 6 069 6 548 7 027 7 506 7 985 8 464 8 943 9 422 9 901 10 379 10 858 11 337 11 816 12 295 12 774 13 253 13 732 14 211 14 690 15 169 15 648 16 127 16 605 17 084 17 563 18 042 18 521 19 000 19 479 19 958 20 437 20 912 21 395 21 870 22 352 22 827 23 310 23 785 24 268 24 743 25 226
lb/h 10%
Real flow
1.968
L
4 074 4 770 5 466 6 162 6 858 7 554 8 250 8 945 9 641 10 337 11 033 11 729 12 425 13 121 13 817 14 513 15 209 15 905 16 600 17 296 17 992 18 688 19 384 20 080 20 776 21 472 22 168 22 864 23 559 24 255 24 951 25 647 26343 27 039 27 735 28 431 29 127 29 823 30 513 31 214 31 905 32 606 33 296 33 998 34 688 35 390 36 080 36 782
lb/h 3% 4 216 4 959 5 702 6 446 7 189 7 932 8 675 9 418 10 162 10 905 11 648 12 391 13 134 13 878 14 261 15 364 16 107 16 850 17 594 18 337 19 080 19 823 20 566 21 310 22 053 22 796 23 539 24 282 25 026 25 769 26 512 27 255 27 998 28 742 29 485 30 228 30 971 31 714 32 452 33 201 33 938 34 687 35 424 36 174 36 911 37 660 38 397 39 146
lb/h 10%
Real flow
3.054
M
5 131 6 007 6 883 7 760 8 636 9 513 10 389 11 265 12 142 13 018 13 894 14 771 15 647 16 524 17 400 18 276 19 153 20 029 20 905 21 782 22 658 23 535 24 411 25 287 26 164 27 040 27 916 28 793 29 669 30 546 31 422 32 298 33 175 34 051 34 927 35 804 36 680 37 557 38 426 39 309 40 179 41 062 41 931 42 815 43 684 44 568 45 436 46 320
lb/h 3% 5 308 6 244 7 180 8 116 9 052 9 987 10 923 11 859 12 795 13 730 14 666 15 602 16 538 17 474 18 409 19 345 20 281 21 217 22 152 23 088 24 024 24 960 25 896 26 831 27 767 28 703 29 639 30 574 31 510 32 446 33 382 34 317 35 253 36 189 37 125 38 061 38 996 39 932 40 868 41 804 42 739 43 675 44 611 45 547 46 483 47 418 48 354 49 290
lb/h 10%
Real flow
3.846
N
6 181 7 236 8 292 9 348 10 403 11 459 12 515 13 570 14 626 15 682 16 738 17 793 18 849 19 905 20 960 22 016 23 072 24 128 25 183 26 239 27 295 28 350 29 406 30 462 31 518 32 573 33 629 34 685 35 740 36 796 37 852 38 907 39 963 41 019 42 075 43 130 44 186 45 242 46 290 47 353 48 401 49 465 50 512 51 576 52 623 53 687 54 734 55 799
lb/h 3% 6 395 7 522 8 649 9 776 10 904 12 031 13 158 14 286 15 413 16 540 17 667 18 795 19 922 21 049 22 176 23 304 24 431 25 558 26 685 27 813 28 940 30 067 31 194 32 322 33 449 34 576 35 704 36 831 37 958 39 085 40 212 41 340 42 467 43 594 44 722 45 849 46 976 48 103 49 231 50 358 51 485 52 612 53 740 54 867 55 994 57 122 58 249 59 376
lb/h 10%
Real flow
4.633
P
9 111 10 668 12 224 13 780 15 337 16 893 18 449 20 006 21 562 23 118 24 675 26 231 27 567 29 344 30 900 32 456 34 013 35 569 37 125 38 682 40 238 41 001 43 351 44 907 46 463 48 020 49576 51 132 52 689 54 245 55 801 57 358 58 914 60 470 62 027 63 583 65 139 66 696 68 240 69 808 71 352 72 921 74 465 76 034 77 577 79 146 80 689 82 259
lb/h 3% 9 427 11 089 12 751 14 413 16 074 17 736 19 398 21 060 22 722 24 383 26 045 27 707 29 369 31 031 32 693 34 354 36 016 37 678 39 340 41 002 42 663 44 325 45 987 47 649 49 311 50 973 52 634 54 296 55 958 57 620 59 282 60 943 62 605 64 267 65 929 67 591 69 253 70 914 72 576 74 238 75 900 77 562 79 223 80 885 82 547 84 209 85 871 87 533
lb/h 10%
Real flow
6.830
Q
15 756 18 447 21 139 23830 26 521 29 213 31 904 34 595 37 287 39 978 42 670 45 361 48 052 50 744 53 435 56 126 58 818 61 509 64 200 66 892 69 583 72 274 74 966 77 657 80 348 83 040 85 731 88 422 91 114 93 805 96 496 99 188 101 879 104 570 107 262 109 953 112 644 115 336 118 007 120 718 123 389 126 101 128 770 131 484 134 152 136 866 139 534 142 249
lb/h 3% 16 302 19 176 22 050 24 923 27 797 30 671 33 545 36 418 39 292 42 166 45 040 47 913 50 787 53 661 56 535 59 408 62 282 65 156 68 030 70 903 73 777 76 651 79 525 82 398 85 272 88 146 91 020 93 893 96 767 99 641 102 515 105 388 108 262 111 136 114 010 116 883 119 757 122 631 125 505 128 378 131 252 134 126 137 000 139 874 142 747 145 621 148 495 151 369
lb/h 10%
Real flow
11.811
R
22 842 26 744 30 646 34 548 38 449 42 351 46 253 50 155 54 057 57 958 61 860 65 762 69 664 73 565 77 467 81 369 85 271 89 173 93 074 96 976 100 878 104 780 108 681 112 583 116 485 120 387 124 288 128 190 132 092 135 994 139 896 143 797 147 699 151 601 155 503 159 404 163 306 167 208 171 080 175 012 178 883 182 815 18 685 190 619 194 487 198 422 202 289 206 226
lb/h 3% 23 634 27 800 31 966 36 133 40 299 44 465 48 631 52 797 56 964 61 130 65 296 69 462 73 629 77 795 81 961 86 127 90 294 94 460 98 626 102 792 106 958 111 125 115 291 119 457 123 623 127 790 131 956 136 122 140 288 144 454 148 621 152 787 156 953 161 119 165 286 169 452 173 618 177 784 181 951 186 117 190 283 194 449 198 615 202 782 206 948 211 114 215 280 219 447
lb/h 10%
Real flow
17.123
Page 3 of 5
1. lb /h steam, 90% of actual capacity at 3% accumulation in accordance with ASME Code, Section I. 2. lb /h steam, 90% of actual capacity at 10% accumulation in accordance with ASME Code, Section VIII.
Capacities
SV73 Cast Iron Safety Valve
TI-S13-25 CH Issue 11
Page 4 of 5
Safety valve sizing information Formulas: For steam service:
For organic fluid vaporizers - lb / h:
Where: A = Required orifice area in square inches P = Relieving pressure in pounds per square inch absolute = set pressure (psi g) + overpressure + 14.7 where the overpressure is 3% or 2 psi, whichever is the greater. P = 1.03 x set pressure + 14.7 or P = set pressure + 2 psi + 14.7. T = Inlet temperature, °F. Absolute (°F plus 460). = Required steam capacity in pounds per hour. = Required vapor capacity in pounds per hour. Kd = Coefficient of discharge, 0.955 for steam, air and vapour service. Ksh = Steam superheat correction factor. See Table 1 below. M = Average molecular weight of vapour. See Table 2, page 5. C = Gas or vapour flow constant. See Table 3, page 5. Z = Compressibility factor corresponding to T and P. If this factor is not available, compressibility correction can be safely ignored using a value of Z = 1.0.
Table 1 Ksh superheat correction factor Total steam temperature °F
Set pressure psi g 15
20
40
60
80
100
120
140
250
259
287
308
324
338
350
361
280
1.00
1.00
-
-
-
-
-
300
1.00
1.00
1.00
-
-
-
320
1.00
1.00
1.00
1.00
-
340
0.99
0.99
1.00
1.00
360
0.99
0.99
0.99
380
0.98
0.98
400
0.98
420
0.97
160
180
200
220
240
250
371
380
388
395
403
406
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
1.00
-
-
-
-
-
-
-
-
-
0.99
1.00
1.00
1.00
-
-
-
-
-
-
-
0.99
0.99
0.99
1.00
1.00
1.00
1.00
-
-
-
-
-
0.98
0.98
0.98
0.99
0.99
0.99
1.00
1.00
1.00
1.00
1.00
-
-
0.97
0.97
0.97
0.98
0.98
0.98
0.99
0.99
0.99
0.99
1.00
1.00
1.00
Saturated steam temperature °F
SV73 Cast Iron Safety Valve
TI-S13-25 CH Issue 11
Page 5 of 5
Sizing and selection
Refer to:- http: // www.spiraxsarco.com / resources / steam-engineering-tutorials / safety-valves / safety-valve-sizing.asp
Dimensions, weights and orifice sizes (approximate) in inches and lbs Valve inlet Size 1½" 2" 2½" 3" 1½" 2" 2" 2½" 2½" 3" 3" 3" 3" 4" 4" 6" 6"
Connection NPT NPT NPT NPT ANSI 250 ANSI 250 ANSI 250 ANSI 250 ANSI 250 ANSI 250 ANSI 250 ANSI 250 ANSI 250 ANSI 250 ANSI 250 ANSI 250 ANSI 250
Valve outlet Size 2½" 3" 4" 4" 2½" 2½" 3" 3" 4" 4" 4" 4" 4" 6" 6" 8" 8"
Connection NPT NPT NPT NPT NPT NPT NPT NPT NPT NPT NPT ANSI 125 ANSI 125 ANSI 125 ANSI 125 ANSI 125 ANSI 125
Orifice
A
letter J K L M J J K K L L M L M N P Q R
ins 3.5 4.0 4.6 5.1 3.5 3.5 4.0 4.0 4.6 4.6 5.1 -
A1
B
ins 5.5 5.5 7.1 7.1 9.3 10.0
ins 4.3 4.6 5.5 5.6 4.3 4.3 4.6 4.6 5.5 5.5 5.4 5.5 5.4 6.8 6.8 9.3 10.9
C
Weight
ins 15.8 17.1 18.5 24.3 15.8 15.8 17.1 17.1 19.5 19.5 24.3 19.5 24.3 26.5 28.5 34.5 43.9
lbs 33 46 66 93 38 40 49 51 71 73 101 82 110 187 196 355 595
Safety information, installation and maintenance
For full details see the Installation and Maintenance Instructions (IM-S13-33) supplied with the product. Installation note: The safety valve should always be fitted with the centre line of the spring housing vertically above the valve.
SV7 safety valve selection guide
C
Series number
SV7
Construction
3 = Cast iron
B Size and connection
C
Actual orifice area Sq. In.
Set pressure SV7 B A
3
3
V = ASME Code Section I U = ASME Code Section VIII V Blank = Valve without code stamp A = 1½" NPT x 2½" NPT B = 2" NPT x 3" NPT C = 2½" NPT x 4" NPT D = 3" NPT x 4" NPT E = 1½" ANSI 250 x 2½" NPT F = 2" ANSI 250 x 2½ NPT G = 2" ANSI 250 x 3" NPT A H = 2½" ANSI 250 x 3" NPT I = 2½" ANSI 250 x 4" NPT J = 3" ANSI 250 x 4 NPT L = 3" ANSI 250 x 4 ANSI 125 N = 4" ANSI 250 x 6" ANSI 125 Q = 6" ANSI 250 x 8" ANSI 125 J = 1.374 K = 1.968 L = 3.054 M = 3.846 J N = 4.633 P = 6.830 Q = 11.811 R = 17.123 Specify set pressure from 180 5 psi g to 250 psi g
ASME section
A1
SV7
-
V
-
A
J
-
180
How to order
Example: 1 off Spirax Sarco SV73-V-AJ-180 safety valve having a set pressure of 180 psi g.
SV73 Cast Iron Safety Valve
TI-S13-25 CH Issue 11
