1.0 Purpose Line Blank Specification Page 1 of 14 1.1 This document provides specifications for line blanks (a.k.a. slip blanks, pancakes, paddle blanks) NPS 1/2 through NPS 24 up through Class 1500 and NPS 1/2 through NPS 12 up through Class 2500 designed as positive shut-off devices in ASME B16.5 raised face metal flanges and plastic lined pipe flanges. These line blanks may be used. 1.1.1 To seal off part of a process permanently. 1.1.2 To prevent accidental flow through a pipeline or into a vessel when installed adjacent to, or in conjunction with, a valve during temporary maintenance activity. 1.1.3 As isolation for hydrostatic or pneumatic testing. 1.2 Line blanks for ring type joint (RTJ) flanges are not covered in this document. Refer to ASME B16.48 to specify RTJ line blanks. 1.3 Line blanks for flat face flanges constructed of gray cast iron, FRP, or thermoplastic shall be full face dimensions with full face gaskets. Thicknesses can still be based on this document. 1.4 If line blanks are needed for flanged connections greater than NPS 24, for custom PCE body flanges, or for other non-standard flanges, contact the PCE Discipline TRN. 2.0 To Seal Off Part of a Process Permanently: 2.1 Line blanks according to ASME B16.48 Line Blanks are acceptable for raised face flanges. Flat face flanges require full face line blanks. 2.2 ASME B16.48 line blanks meet the full temperature-pressure ratings based on materials of construction according to ASME B16.5 Table 1-A. 2.2.1 Metal liners which match the material of construction of the piping can be used on the process side of a carbon steel line blank. Metal liner thickness must be verified with calculations if in vacuum service. 2.2.2 Pressure-temperature ratings for carbon steel must be used if a metal liner option is used. 2.3 For reference, required line blank thicknesses according to ASME B16.48 are given in Table 1. Line blanks inserted between components with different pressure ratings shall be selected based on the higher pressure rating. 2.4 Specified gaskets from the CPPS shall be used with line blanks.
Page 2 of 14 3.0 For Temporary (Monitored) Maintenance/Construction Activities: 3.1 Line blanks according to, ASME B16.48 Line Blanks can be used. See Table 1 for required thicknesses. 3.2 Table 2 or Table 3 may be used to determine if thinner, non-standard line blanks are allowed based on the maximum possible pressure in the system being isolated. The pressure rating listed in Table 2 and Table 3 is for temperature up to 300F (149C); the rating listed shall be multiplied by the derating factor tabulated in Table 8 if the temperature exceeds the basis for Table 2 or Table 3. 3.3 Maximum pressure shall be the highest pressure listed in the CPPS heading or determined by Process Engineering/Site Piping TR. 3.4 Table 2 or Table 3 thickness blanks shall be removed when construction has been approved for commissioning. 3.5 The thicknesses listed in Table 2 or Table 3 may be used for non-standard line blanks fabricated from A516 Grade 70, A105, A240 Grade 304/304L or 316/316L. 3.5.1 If other solid alloy line blanks are used, thickness must be verified by calculations. 3.5.2 The 1/8 thickness can be used as a vapor blank for applications where there is NO differential pressure (i.e., air gapped, open ended) but a physical barrier is still needed to prevent vapors/fumes from backing up into a piece of equipment. 3.5.3 Dimensions for non-standard line blanks are shown in Figure 1 and in the applicable pressure class table: 3.5.3.1 Table 4: Class 150, 300, and 600 English Dimensions 3.5.3.2 Table 5: Class 900, 1500, and 2500 English Dimensions 3.5.3.3 Table 6: Class 150, 300, and 600 Metric Dimensions 3.5.3.4 Table 7: Class 900, 1500, and 2500 Metric Dimensions 3.5.4 A gasket phonographic surface finish is not required for non-standard line blanks.
Page 3 of 14 3.6 If carbon steel and stainless steel materials (see Para. 3.2.1) are not compatible with the process: 3.6.1 A 1/8 alloy blind disc compatible with the process may be used on the process side of a line blank. Alloy blind disc thickness must be verified with calculations if in vacuum service. 3.6.2 PTFE liners (e.g., 1/8 Gylon 3510 blind gasket, Pureflex TASK-LINE Fluid Blocker) may be used on the process side of a line blank for ASME B16.5 Class 150 and 300 piping ONLY. PTFE liners are not allowed in vacuum service 3.7 Specified gaskets from the CPPS shall be used with line blanks. 3.7.1 Semi-metallic gaskets (e.g., spiral wound, kammprofile, jacketed) should not be used against PTFE liners. 3.7.2 If PTFE blind gaskets or Pureflex TASK-LINE Fluid Blockers are used as protective liners on the process side of the line blank, then no additional gasket is required. 3.7.3 Full face gaskets shall be used with flat face flanges. 4.0 For Hydrostatic or Pneumatic Testing: 4.1 When line blanks are used as leak testing isolation, the selected line blank shall be capable of withstanding the CPPS listed Maximum Test Pressure. Pressures listed in Table 1, Table 2, or Table 3 are Maximum Allowable Working Pressures (MAWP). Line blanks may be subjected to Maximum Test Pressures exceeding the listed MAWP during system leak tests only: 4.1.1 Up to 1.1 times the stamped MAWP for pneumatic pressure tests. 4.1.2 Up to 1.5 times the stamped MAWP for hydrostatic pressure tests. NOTE: Maximum Test Pressure values may be rounded up to nearest 25 psig increment for hydrostatic test and 1 psig for pneumatic test. 4.2 The associated CPPS will designate the appropriate Test Class and Maximum Test Pressure. 4.3 If testing temperatures exceed 38 C (100 F), the site CPPS Technical Resource shall be consulted to determine if the test pressure would produce a nominal pressure stress or longitudinal stress in excess of the yield strength at test temperature.
Page 4 of 14 5.0 Markings: 5.1 The marking shall be applied by steel stamping on the web (tie bar) or handle. Where space is limited, marking may be stamped on the outside circumference of the blank. 5.2 For ASME B16.48 Line Blanks, the minimum markings are called out in that standard as follows: 5.2.1 Manufacturer s name or trademark. 5.2.2 Material, specification, and grade or class. 5.2.3 Pressure class. 5.2.4 B16 (NOTE: This designation should only be present when the line blank has been manufactured in full compliance with ASME B16.48). 5.2.5 Size (NPS) 5.2.6 Paint the handle yellow per Figure 1, Note 1. 5.3 For non-standard line blanks, markings shall include the following: 5.3.1 Manufacturer name 5.3.2 Material, specification, and grade or class (i.e. ASTM A517 Gr. 70) 5.3.3 Pressure from Table 2 or Table 3 5.3.4 NPS, class, thickness (e.g., 10 150 0.125 ) 5.3.5 Paint the handle yellow per Figure 1, Note 1.
Page 5 of 14 Figure 1 Standard Line Blank Detail Note 1 By Supplier W A Note 2 O t (Note 5) Notes: 1. PROVIDE COLOR AND MARKING AS DESCRIBED IN PARAGRAPH 5 PAINT COLOR SHALL BE ANSI SAFETY YELLOW FOR NORTH AMERICA AND OTHER AREAS (YELLOW RAL 1003 FOR EUROPE) HANDLE SHALL BE SOLID WITH NO HOLE; HOLES ARE ONLY PERMITTED IN PADDLE SPACERS PER ASME B16.48 2. TAB THICKNESS SHALL BE, "t" 3. SEE TABLES 4 THRU 7 FOR DIAMETER AND TABLE 1 FOR THICKNESS 4. BREAK SHARP CORNERS 5. SEE TABLE 1 FOR STANDARD LINE BLANK THICKNESS
Page 6 of 14 Figure 2 Non-Standard Line Blank Detail Note 1 W 4" (102) Dia A Note 2 O t (Note 5) Notes: 1. PROVIDE COLOR AND MARKING AS DESCRIBED IN PARAGRAPH 5 PAINT COLOR SHALL BE ANSI SAFETY YELLOW FOR NORTH AMERICA AND OTHER AREAS (YELLOW RAL 1003 FOR EUROPE) HANDLE SHALL BE SOLID WITH NO HOLE; HOLES ARE ONLY PERMITTED IN PADDLE SPACERS PER ASME B16.48 2. TAB THICKNESS SHALL BE, "t" 3. SEE TABLES 4 THRU 7 FOR DIMENSIONS 4. BREAK SHARP CORNERS 5. SEE TABLE 2 FOR NON-STANDARD LINE BLANK THICKNESS
Page 7 of 14 Table 1 Full Rating ASME B16.48 Line Blank Thickness for Standard Flanges Class 150 300 600 900 1500 2500 NPS in (mm) in (mm) in (mm) in (mm) in (mm) in (mm) 1/2 1/8 (3) 1/4 (6.4) 1/4 (6.4) 1/4 (6.4) 1/4 (6.4) 3/8 (9.7) 3/4 1/8 (3) 1/4 (6.4) 1/4 (6.4) 1/4 (6.4) 3/8 (9.7) 3/8 (9.7) 1 1/8 (3) 1/4 (6.4) 1/4 (6.4) 1/4 (6.4) 3/8 (9.7) 3/8 (9.7) 1-1/2 1/4 (6.4) 1/4 (6.4) 3/8 (9.7) 3/8 (9.7) 1/2 (12.7) 5/8 (15.7) 2 1/4 (6.4) 3/8 (9.7) 3/8 (9.7) 1/2 (12.7) 1/2 (12.7) 5/8 (15.7) 3 3/8 (9.7) 3/8 (9.7) 1/2 (12.7) 5/8 (15.7) 3/4 (19.1) 7/8 (22.4) 4 3/8 (9.7) 1/2 (12.7) 5/8 (15.7) 3/4 (19.1) 7/8 (22.4) 1-1/8 (28.4) 6 1/2 (12.7) 5/8 (15.7) 7/8 (22.4) 1 (25.4) 1-3/8 (35.1) 1-5/8 (41.1) 8 1/2 (12.7) 7/8 (22.4) 1-1/8 (28.4) 1-3/8 (35.1) 1-5/8 (41.1) 2-1/8 (53.8) 10 5/8 (15.7) 1 (25.4) 1-3/8 (35.1) 1-5/8 (41.1) 2 (50.8) 2-5/8 (66.5) 12 3/4 (19.1) 1-1/8 (28.4) 1-5/8 (41.1) 1-7/8 (47.8) 2-5/8 (66.5) 3-1/8 (79.2) 14 3/4 (19.1) 1-1/4 (31.8) 1-3/4 (44.5) 2-1/8 (53.8) 2-5/8 (66.5) --- 16 7/8 (22.4) 1-1/.2 (38.1) 2 (50.8) 2-3/8 (60.5) 3 (76.2) --- 18 1 (25.4) 1-5/8 (41.1) 2-1/8 (53.8) 2-5/8 (66.5) 3-3/8 (85.9) --- 20 1-1/8 (28.4) 1-3/4 (44.5) 2-1/2 (63.5) 2-7/8 (73.2) 2-3/4 (95.3) --- 24 1-1/4 (31.8) 2 (50.8) 2-7/8 (73.2) 3-1/2 (88.9) 4-3/8 (111.3) ---
Page 8 of 14 Table 2 Maximum Working Pressure Differential (PSIG) Tabulated for Line Blank Thickness (*) Blank Thk Flange Size (NPS) in. (mm) 1/2 3/4 1 1 1/2 2 3 4 6 8 10 12 14 16 18 20 24 1/8 (3) 2362 1483 971 457 294 136 82 38 22 14 10 9 7 5 4 3 1/4 (6) 9448 5933 3885 1827 1177 544 329 152 90 58 41 34 26 21 17 12 3/8 (10) 21259 13350 8741 4112 2648 1224 741 342 202 130 92 77 59 46 38 26 1/2 (13) 37793 23733 15539 7310 4708 2177 1317 608 359 231 164 136 104 82 67 46 5/8 (16) 59051 37083 24280 11421 7356 3401 2058 951 561 361 256 213 163 129 104 72 3/4 (19) 85034 53400 34963 16447 10592 4898 2963 1369 807 519 369 306 234 185 150 104 7/8 (22) 115741 72683 47589 22386 14418 6667 4033 1863 1099 707 502 417 319 252 204 142 1 (25) 151172 94933 62156 29239 18831 8707 5267 2434 1436 923 656 544 417 329 267 185 1-1/8 (29) 191327 120150 78667 37006 23833 11020 6667 3080 1817 1168 830 689 527 417 338 234 1-1/4 (32) 236206 148333 97119 45686 29424 13605 8230 3803 2243 1442 1025 850 651 514 417 289 1-3/8 (35) 285809 179483 117515 55280 35602 16463 9959 4602 2714 1745 1241 1029 788 622 504 350 1-1/2 (38) 340136 213599 139852 65788 42370 19592 11852 5476 3230 2077 1476 1224 938 741 600 417 1-5/8 (41) 399187 250682 164132 77209 49726 22993 13909 6427 3791 2437 1733 1437 1100 869 704 489 1-3/4 (44) 462963 290732 190354 89544 57670 26667 16132 7454 4396 2827 2009 1667 1276 1008 817 567 1-7/8 (48) 531463 333749 218519 102793 66203 30612 18519 8557 5047 3245 2307 1913 1465 1157 938 651 2 (51) 604686 379732 248626 116956 75324 34830 21070 9736 5742 3692 2625 2177 1667 1317 1067 741 2-1/8 (54) 682634 428682 280675 132032 85034 39320 23786 10991 6482 4168 2963 2457 1882 1487 1204 836 2-1/4 (57) 765306 480598 314667 148022 95332 44082 26667 12322 7267 4673 3322 2755 2109 1667 1350 938 2-3/8 (60) 852702 535481 350601 164926 106219 49116 29712 13729 8097 5206 3701 3070 2350 1857 1504 1045 2-1/2 (64) 944822 593331 388478 182744 117694 54422 32922 15212 8972 5769 4101 3401 2604 2058 1667 1157 2-5/8 (67) 1041667 654147 428297 201475 129758 60000 36296 16771 9892 6360 4521 3750 2871 2269 1838 1276 2-3/4 (70) 1143235 717930 470058 221120 142410 65850 39835 18407 10856 6980 4962 4116 3151 2490 2017 1400 2-7/8 (73) 1249528 784680 513762 241678 155650 71973 43539 20118 11866 7629 5424 4498 3444 2721 2204 1531 3 (76) 1360544 854397 559408 263151 169480 78367 47407 21906 12920 8307 5905 4898 3750 2963 2400 1667 3-1/8 (79) 1476285 927080 606996 285537 183897 85034 51440 23769 14019 9014 6408 5315 4069 3215 2604 1808 3-1/4 (83) 1596750 1002729 656527 308837 198903 91973 55638 25709 15163 9749 6931 5748 4401 3477 2817 1956 3-3/8 (86) 1721939 1081346 708001 333050 214498 99184 60000 27724 16352 10514 7474 6199 4746 3750 3038 2109 3-1/2 (89) 1851852 1162929 761416 358177 230681 106667 64527 29816 17585 11307 8038 6667 5104 4033 3267 2269 3-5/8 (92) 1986489 1247478 816774 384218 247452 114422 69218 31984 18864 12129 8622 7151 5475 4326 3504 2433 3-3/4 (95) 2125850 1334995 874075 411173 264812 122449 74074 34228 20187 12980 9227 7653 5859 4630 3750 2604 3-7/8 (98) 2269936 1425478 933318 439041 282760 130748 79095 36547 21555 13860 9853 8172 6257 4943 4004 2781 (*)-Pressure rating is tabulated up to 300ºF; pressure rating must be multiplied by the derating factor in Table 8 for higher temperature. Maximum Test Pressure maybe as high as 1.5 x Maximum Working Pressure
Page 9 of 14 Table 3 Maximum Working Pressure Differential (Bar) Tabulated for Line Blank Thickness Line blank material of construction: A-105, A-516-70, A-240 dual marked 304/304L, or A-240 dual marked 316/316L. Blank Thk Flange Size (NPS) in. (mm) 0.5 0.75 1 1.5 2 3 4 6 8 10 12 14 16 18 20 24 1/8 (3) 162.9 102.3 67.0 31.5 20.3 9.4 5.7 2.6 1.5 1.0 0.7 0.6 0.4 0.4 0.3 0.2 1/4 (6) 651.4 409.1 267.8 126.0 81.1 37.5 22.7 10.5 6.2 4.0 2.8 2.3 1.8 1.4 1.1 0.8 3/8 (10) 1465.7 920.4 602.7 283.5 182.6 84.4 51.1 23.6 13.9 8.9 6.4 5.3 4.0 3.2 2.6 1.8 1/2 (13) 2605.7 1636.3 1071.4 504.0 324.6 150.1 90.8 42.0 24.7 15.9 11.3 9.4 7.2 5.7 4.6 3.2 5/8 (16) 4071.5 2556.8 1674.0 787.5 507.2 234.5 141.9 65.6 38.7 24.9 17.7 14.7 11.2 8.9 7.2 5.0 3/4 (19) 5862.9 3681.8 2410.6 1134.0 730.3 337.7 204.3 94.4 55.7 35.8 25.4 21.1 16.2 12.8 10.3 7.2 7/8 (22) 7980.0 5011.3 3281.1 1543.5 994.1 459.7 278.1 128.5 75.8 48.7 34.6 28.7 22.0 17.4 14.1 9.8 1 (25) 10422.9 6545.4 4285.5 2016.0 1298.4 600.4 363.2 167.8 99.0 63.6 45.2 37.5 28.7 22.7 18.4 12.8 1-1/8 (29) 13191.5 8284.0 5423.9 2551.4 1643.2 759.8 459.7 212.4 125.3 80.5 57.3 47.5 36.4 28.7 23.3 16.2 1-1/4 (32) 16285.8 10227.2 6696.2 3149.9 2028.7 938.1 567.5 262.2 154.7 99.4 70.7 58.6 44.9 35.5 28.7 20.0 1-3/8 (35) 19705.8 12374.9 8102.3 3811.4 2454.7 1135.1 686.6 317.3 187.1 120.3 85.5 70.9 54.3 42.9 34.8 24.1 1-1/2 (38) 23451.6 14727.1 9642.5 4535.9 2921.3 1350.8 817.2 377.6 222.7 143.2 101.8 84.4 64.6 51.1 41.4 28.7 1-5/8 (41) 27523.0 17283.9 11316.5 5323.4 3428.5 1585.3 959.0 443.1 261.4 168.0 119.5 99.1 75.9 59.9 48.6 33.7 1-3/4 (44) 31920.2 20045.3 13124.5 6173.9 3976.2 1838.6 1112.2 513.9 303.1 194.9 138.5 114.9 88.0 69.5 56.3 39.1 1-7/8 (48) 36643.1 23011.2 15066.3 7087.3 4564.5 2110.6 1276.8 590.0 348.0 223.7 159.0 131.9 101.0 79.8 64.6 44.9 2 (51) 41691.7 26181.6 17142.1 8063.8 5193.4 2401.4 1452.7 671.3 395.9 254.6 181.0 150.1 114.9 90.8 73.5 51.1 2-1/8 (54) 47066.0 29556.6 19351.9 9103.3 5862.9 2711.0 1640.0 757.8 446.9 287.4 204.3 169.4 129.7 102.5 83.0 57.7 2-1/4 (57) 52766.0 33136.1 21695.5 10205.8 6572.9 3039.3 1838.6 849.6 501.1 322.2 229.0 190.0 145.4 114.9 93.1 64.6 2-3/8 (60) 58791.8 36920.1 24173.1 11371.3 7323.5 3386.4 2048.6 946.6 558.3 359.0 255.2 211.7 162.0 128.0 103.7 72.0 2-1/2 (64) 65143.2 40908.7 26784.6 12599.7 8114.7 3752.2 2269.9 1048.8 618.6 397.8 282.8 234.5 179.6 141.9 114.9 79.8 2-5/8 (67) 71820.4 45101.9 29530.0 13891.2 8946.5 4136.9 2502.5 1156.4 682.0 438.5 311.7 258.6 198.0 156.4 126.7 88.0 2-3/4 (70) 78823.3 49499.6 32409.4 15245.7 9818.8 4540.2 2746.6 1269.1 748.5 481.3 342.1 283.8 217.3 171.7 139.0 96.6 2-7/8 (73) 86151.9 54101.8 35422.6 16663.1 10731.7 4962.4 3001.9 1387.1 818.1 526.0 373.9 310.1 237.5 187.6 152.0 105.5 3 (76) 93806.2 58908.6 38569.8 18143.6 11685.2 5403.2 3268.6 1510.3 890.8 572.8 407.2 337.7 258.6 204.3 165.5 114.9 3-1/8 (79) 101786.3 63919.9 41850.9 19687.1 12679.3 5862.9 3546.7 1638.8 966.6 621.5 441.8 366.4 280.5 221.7 179.6 124.7 3-1/4 (83) 110092.1 69135.8 45266.0 21293.5 13713.9 6341.3 3836.1 1772.6 1045.4 672.2 477.9 396.3 303.4 239.8 194.2 134.9 3-3/8 (86) 118723.5 74556.2 48814.9 22963.0 14789.1 6838.5 4136.9 1911.5 1127.4 724.9 515.3 427.4 327.2 258.6 209.4 145.4 3-1/2 (89) 127680.7 80181.1 52497.8 24695.5 15904.9 7354.4 4449.0 2055.7 1212.5 779.6 554.2 459.7 351.9 278.1 225.2 156.4 3-5/8 (92) 136963.6 86010.6 56314.6 26490.9 17061.2 7889.1 4772.4 2205.2 1300.6 836.3 594.5 493.1 377.5 298.3 241.6 167.8 3-3/4 (95) 146572.3 92044.7 60265.4 28349.4 18258.1 8442.6 5107.2 2359.9 1391.9 894.9 636.2 527.7 404.0 319.2 258.6 179.6 3-7/8 (98) 156506.6 98283.2 64350.0 30270.8 19495.6 9014.8 5453.4 2519.9 1486.2 955.6 679.3 563.4 431.4 340.8 276.1 191.7 Pressure rating is tabulated up to 149ºCl Pressure rating must be multiplied by the derating factor in Table 8 for higher pressure. Maximum Test Pressure may be as high as 1.5x maximum Working Pressure.
Page 10 of 14 Notes: Table 4 Class 150, 300, and 600 English Dimensions Class 150 300 600 NPS O, (in) O, (in) O, (in) Handle Length A, (in) Web Width W, (in) 1/2 1.75 2.00 2.00 5.00 1.00 3/4 2.12 2.50 2.50 5.00 1.00 1 2.50 2.75 2.75 5.00 1.00 1-1/2 3.25 3.62 3.62 5.00 1.00 2 4.00 4.25 4.25 5.00 1.00 3 5.25 5.75 5.75 5.00 1.00 4 6.75 7.00 7.50 8.00 1.00 6 8.62 9.75 10.38 5.00 1.00 8 10.88 12.00 12.50 5.00 1.00 10 13.25 14.12 15.62 7.00 1.00 12 16.00 16.50 17.88 7.00 1.00 14 17.62 19.00 19.25 7.00 1.00 16 20.12 21.12 22.12 7.00 1.00 18 21.50 23.38 24.00 7.00 1.00 20 23.75 25.62 26.75 7.00 1.00 24 28.12 30.38 31.00 7.00 1.00 1. See Figure 1 for details 2. See Table 2 for pressure vs. thickness relationship.
Page 11 of 14 Notes: Table 5 Class 900, 1500, and 2500 English Dimensions Class 900 1500 2500 NPS O, (in) O, (in) O, (in) Handle Length A, (in) Web Width W, (in) 1/2 2.38 2.38 2.62 6.00 1.00 3/4 2.62 2.62 2.88 6.00 1.00 1 3.00 3.00 3.25 6.00 1.00 1-1/2 3.75 3.75 4.50 6.00 1.00 2 5.50 5.50 5.62 6.00 1.00 3 6.50 6.75 7.62 6.00 1.00 4 8.00 8.12 9.12 6.00 1.00 6 11.25 11.00 12.38 6.00 1.00 8 14.00 13.75 15.12 6.00 1.00 10 17.00 17.00 18.62 11.00 1.00 12 19.50 20.38 21.50 11.00 1.00 14 20.38 22.62 --- 11.00 1.00 16 22.50 25.12 --- 11.00 1.00 18 25.00 27.62 --- 11.00 1.00 20 27.38 29.62 --- 11.00 1.00 24 32.88 35.38 --- 11.00 1.00 1. See Figure 1 for details 2. See Table 2 for pressure vs. thickness relationship.
Page 12 of 14 Notes: Table 6 Class 150, 300, and 600 Metric Dimensions Class 150 300 600 NPS O, (mm) O, (mm) O, (mm) Handle Length A, (mm) Web Width W, (mm) 1/2 44 51 51 127 25 3/4 54 64 64 127 25 1 64 70 70 127 25 1-1/2 83 92 92 127 25 2 102 108 108 127 25 3 133 146 146 127 25 4 171 178 191 127 25 6 219 248 264 127 25 8 276 305 318 127 25 10 337 359 397 178 25 12 406 419 454 178 25 14 448 483 489 178 25 16 511 536 562 178 25 18 546 594 610 178 25 20 603 651 679 178 25 24 714 772 787 178 25 1. See Figure 1 for details 2. See Table 2 for pressure vs. thickness relationship.
Page 13 of 14 Notes: Table 7 Class 900, 1500, and 2500 Metric Dimensions Class 900 1500 2500 NPS O, (mm) O, (mm) O, (mm) Handle Length A, (mm) Web Width W, (mm) 1/2 60 60 67 152 25 3/4 67 67 73 152 25 1 76 76 83 152 25 1-1/2 95 95 114 152 25 2 140 140 143 152 25 3 165 171 194 152 25 4 203 206 232 152 25 6 286 279 314 152 25 8 356 349 384 152 25 10 432 432 473 279 25 12 495 518 546 279 25 14 518 575 --- 279 25 16 572 638 --- 279 25 18 635 702 --- 279 25 20 695 752 --- 279 25 24 835 899 --- 279 25 3. See Figure 1 for details 4. See Table 2 for pressure vs. thickness relationship.
Page 14 of 14 Table 8 Elevated Temperature Derating Factors for Table 2 and Table 3 Temperature (F) Temperature (C) Derating Factor up to 300 up to 149 1.00 400 204 0.94 500 260 0.88 600 316 0.84 700 371 0.82 Example: What is the appropriate thickness of a non-standard line blank to use for secondary isolation on a NPS 6, Class 150 flanged piping per PU02 in 175# steam service? The line normally operates at 175 psig at 385 o F, with an upper limit based on the Energy and Utilities distribution specification of 193 psig at 420 o F. The plant steam header has reliefs upstream of the isolation point set at 180psig. Table 2 states that a 1/4 inch thick line blank is rated up to 152 psig at ambient temperature, this is not sufficient to provide isolation of the piping system. A 3/8 inch thick line blank made of ASTM A-516-70 would be rated for 342 psig at ambient temperatures. Saturated steam at the relief set point of 180 psig is 380 o F. Applying the derating factor of 0.94 per Table 8 determines that the line blank would be rated for 321psig at 400 o F. The 3/8 inch thick blank would be sufficient for secondary isolation of the 175# steam system with a relief set at 180 psig. References: ASME B16.48; Line Blanks