Line Blank Specification

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1 1.0 Purpose Line Blank Specification Page 1 of 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 To seal off part of a process permanently 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 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 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 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.

2 Page 2 of 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 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 If other solid alloy line blanks are used, thickness must be verified by calculations 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 Dimensions for non-standard line blanks are shown in Figure 1 and in the applicable pressure class table: Table 4: Class 150, 300, and 600 English Dimensions Table 5: Class 900, 1500, and 2500 English Dimensions Table 6: Class 150, 300, and 600 Metric Dimensions Table 7: Class 900, 1500, and 2500 Metric Dimensions A gasket phonographic surface finish is not required for non-standard line blanks.

3 Page 3 of If carbon steel and stainless steel materials (see Para ) are not compatible with the process: 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 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 Semi-metallic gaskets (e.g., spiral wound, kammprofile, jacketed) should not be used against PTFE liners 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 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: Up to 1.1 times the stamped MAWP for pneumatic pressure tests 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.

4 Page 4 of 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: Manufacturer s name or trademark Material, specification, and grade or class Pressure class B16 (NOTE: This designation should only be present when the line blank has been manufactured in full compliance with ASME B16.48) Size (NPS) Paint the handle yellow per Figure 1, Note For non-standard line blanks, markings shall include the following: Manufacturer name Material, specification, and grade or class (i.e. ASTM A517 Gr. 70) Pressure from Table 2 or Table NPS, class, thickness (e.g., ) Paint the handle yellow per Figure 1, Note 1.

5 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 B 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

6 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 B 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

7 Page 7 of 14 Table 1 Full Rating ASME B16.48 Line Blank Thickness for Standard Flanges Class 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) /8 (22.4) 1-1/.2 (38.1) 2 (50.8) 2-3/8 (60.5) 3 (76.2) (25.4) 1-5/8 (41.1) 2-1/8 (53.8) 2-5/8 (66.5) 3-3/8 (85.9) /8 (28.4) 1-3/4 (44.5) 2-1/2 (63.5) 2-7/8 (73.2) 2-3/4 (95.3) /4 (31.8) 2 (50.8) 2-7/8 (73.2) 3-1/2 (88.9) 4-3/8 (111.3) ---

8 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/ / /8 (3) /4 (6) /8 (10) /2 (13) /8 (16) /4 (19) /8 (22) (25) /8 (29) /4 (32) /8 (35) /2 (38) /8 (41) /4 (44) /8 (48) (51) /8 (54) /4 (57) /8 (60) /2 (64) /8 (67) /4 (70) /8 (73) (76) /8 (79) /4 (83) /8 (86) /2 (89) /8 (92) /4 (95) /8 (98) (*)-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

9 Page 9 of 14 Table 3 Maximum Working Pressure Differential (Bar) Tabulated for Line Blank Thickness Line blank material of construction: A-105, A , A-240 dual marked 304/304L, or A-240 dual marked 316/316L. Blank Thk Flange Size (NPS) in. (mm) /8 (3) /4 (6) /8 (10) /2 (13) /8 (16) /4 (19) /8 (22) (25) /8 (29) /4 (32) /8 (35) /2 (38) /8 (41) /4 (44) /8 (48) (51) /8 (54) /4 (57) /8 (60) /2 (64) /8 (67) /4 (70) /8 (73) (76) /8 (79) /4 (83) /8 (86) /2 (89) /8 (92) /4 (95) /8 (98) 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.

10 Page 10 of 14 Notes: Table 4 Class 150, 300, and 600 English Dimensions Class NPS O, (in) O, (in) O, (in) Handle Length A, (in) Web Width W, (in) 1/ / / See Figure 1 for details 2. See Table 2 for pressure vs. thickness relationship.

11 Page 11 of 14 Notes: Table 5 Class 900, 1500, and 2500 English Dimensions Class NPS O, (in) O, (in) O, (in) Handle Length A, (in) Web Width W, (in) 1/ / / See Figure 1 for details 2. See Table 2 for pressure vs. thickness relationship.

12 Page 12 of 14 Notes: Table 6 Class 150, 300, and 600 Metric Dimensions Class NPS O, (mm) O, (mm) O, (mm) Handle Length A, (mm) Web Width W, (mm) 1/ / / See Figure 1 for details 2. See Table 2 for pressure vs. thickness relationship.

13 Page 13 of 14 Notes: Table 7 Class 900, 1500, and 2500 Metric Dimensions Class NPS O, (mm) O, (mm) O, (mm) Handle Length A, (mm) Web Width W, (mm) 1/ / / See Figure 1 for details 4. See Table 2 for pressure vs. thickness relationship.

14 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 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 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

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