1. PURPOSE
1.1 This engineering specification lists recommended bolting materials to be used when bolting flanged assemblies for a variety of applications typically found in Air Products air separation facilities.
1.2 Guidance on bolting materials for other applications that are not specifically listed in this document may be obtained by: Referring to the recommended Piping Class Specification as listed in 3PI55001. Referring to a project specific Piping Class Specification as applicable.
2. scope
2.1 This specification applies to the stud bolts, nuts, and washers (when required) for the bolting of similar and dissimilar flange combinations as listed in Table 1.
2.2 Materials included are:
2.2.1 Flanges
| Flange Material | Flange Class and NPS Range | Standard / Specification |
| Aluminum | Class 150-300, NPS 1/2–24 (DN15–600) | ASME B16.5 |
| Class 150-300, NPS 30–48 (DN750–1200) | ASME B16.47 | |
| Brass | Class 150-300, NPS 1-6 (DN25–150) | 4API-57904 |
| Carbon Steel | Class 125 Large Diameter, Light Weight, NPS 26–48 (DN650-1200) | ASME B16.1 AWWA C207, Table 2, Class D |
| Class 125 Large Diameter, NPS 30-60 (DN750-1500) | ASME B16.1 AWWA C207, Table 3, Class E | |
| Class 150-1500, NPS 1/2-24 (DN15-600) | ASME B16.5 | |
| Class 150-900, NPS 30-60 (DN750-1500) | ASME B16.47 | |
| Gray Iron | Class 125, NPS 1-48 (DN25-1200) | ASME B16.1 |
| Stainless Steel | Class 150-1500, NPS 1/2-24 (DN15-600) | ASME B16.5 |
| Class 150-900, NPS 30-48 (DN750-1200) | ASME B16.47 | |
| Monel | Class 150-1500, NPS 1/2-12 (DN15-300) | ASME B16.5 |
2.2.2 Washers ASME B18.21.1
2.2.3 Nuts ASME B18.2.2
2.3 Bolt-up procedures previously contained in this document are now specified in 4WPI-670210.
3. related documents
3.1 Air Products Engineering Documents 3PI55001 Piping Class Specification Application Guide 4API-57904 Brass Plate Flanges (Special) 4WPI-670210 Bolt-up Procedure For Flanged Connections 4API-MASK04 Material Purchase Specification for Stainless Steel Bolting (Underground Utility Service) 4WPI-MCCK01 Material Purchase Specification for Alloy Steel Bolting (GB 3077 Grades 35CrMoA and 30CrMo) 4WPI-MCCK02 Material Purchase Specification for Alloy Steel Bolting (GB 3077 Grades 25Cr2MoVA and 30CrMo) 4WPI-MCCK04 Material Purchase Specification for Carbon Steel Bolting (GB/T 3098.1 Grade 5.6 and GB/T 3098.2 Grade 6) 4WPI-MCSK01 Material Purchase Specification for Stainless Steel Bolting (GB 1220 Grade 0Cr18Ni9) 4WPI-MWCK01 Material Purchase Specification for Alloy Steel Bolting (Grades B7 and 2H) 4WPI-MWCK02 Material Purchase Specification for Alloy Steel Bolting (Grades B16 and 4) 4WPI-MWCK03 Material Purchase Specification for Alloy Steel Bolting (Grades B7M and 2HM) 4WPI-MWCK04 Material Purchase Specification for Carbon Steel Bolting (Grades B and A) 4WPI-MWCK05 Material Purchase Specification for Alloy Steel Bolting for Low Temperature Service (Grades L7 and 7) 4WPI-MWSK01 Material Purchase Specification for Stainless Steel Bolting (Grades B8 and 8) 4WPI-MWSK02 Material Purchase Specification for Stainless Steel Low Temperature Bolting (Grades B8 and 8) 4WPI-MWSK03 Material Purchase Specification for Stainless Steel Bolting ASTM A193 Grade B8M, Class 2 4WPI-MWSK04 Material Purchase Specification for Stainless Steel Bolting ASTM A193 Grade B8MA, Class 1A
3.2 American Society of Mechanical Engineers (ASME) B1.1 Unified Inch Screw Threads (UN and UNR Thread Form) B1.13M Metric Screw Threads: M Profile B16.1 Gray Iron Pipe Flanges and Flanged Fittings, Classes 25, 125, and 250 B16.5 Pipe Flanges and Flanged Fittings NPS ½ through NPS 24 Metric/Inch Standard B16.47 Large Diameter Steel Flanges NPS 26 through NPS 60 Metric/Inch Standard B18.2.2 Square and Hex Nuts (Inch Series) B18.2.6M Metric Fasteners for Use in Structural Applications B18.21.1 Washers: Helical Spring Lock, Tooth Lock, and Plain Washers (Inch Series) B31.3 Process Piping
3.3 American Society for Testing and Materials (ASTM) A 193 Standard Specification for Alloy-Steel and Stainless Steel Bolting Materials for High-Temperature Service A 194 Standard Specification for Carbon and Alloy Steel Nuts for Bolts for High-Pressure and High-Temperature Service A 307 Standard Specification for Carbon Steel Bolts and Studs, 60,000 psi Tensile Strength A 320/A 320M Standard Specification for Alloy Steel Bolting Materials for Low-Temperature Service A 563 Standard Specification for Carbon and Alloy Steel Nuts F593 Standard Specification for Stainless Steel Bolts, Hex Cap Screws, and Studs F594 Standard Specification for Stainless Steel Nuts
3.4 American Water Works Association (AWWA) C207 Steel Pipe Flanges for Waterworks Service – Sizes 4 in (100 mm) through 144 in (3600 mm)
3.3 National Association of Corrosion Engineers (NACE) MR0175/ISO 15156 Materials for Use in H2S-containing Environments in Oil and Gas Production
5. bolting materials
5.1 The thread specification shown is what is normally furnished unless otherwise specified.
5.2. Bolt Materials
| ASTM Bolt Material | ASME Thread Specification | Material Purchase Specifications (MPS) | Equivalent Chinese Bolt Material | Chinese Material Purchase Specifications (MPS) | Bolt Material & Strength | Min. / Max. Temperature Limits Comments/Restrictions |
| ASTM A307 Grade B | B1.1 | 4WPI- MWCK04 | GB/T 3098.1 Grade 5.6 | 4WPI- MCCK04 | Carbon Steel Low Strength | Minimum temperature per ASME B31.3, Table A-2 is -29°C (-20°F). Maximum temperature per AP Specification is +149°C (+300°F). See Note 1. Use only when cast iron flanges might be encountered. |
| ASTM F593 Group 2 | B1.1 | 4API- MASK04 | —– | None | Stainless Steel Low Strength | Minimum and maximum temperature limits per AP Specification is -29°C (-20°F) thru +100°C (+212°F). Use only with high-density polyethylene pipe (HDPE). |
| ASTM A193 Grade B7 | B1.1 B1.13M | 4WPI- MWCK01 | GB3077 Gr. 35CrMoA | 4WPI- MCCK01 | Cr-Mo Alloy Steel High Strength | Minimum temperature per ASME B31.3, Table A-2 is – 40°C (–40°F). Maximum temperature per AP Specification is +427°C (+800°F). See Note 1. |
| ASTM A193 Grade B16 | B1.1 B1.13M | 4WPI- MWCK02 | GB3077 Gr. 25Cr2MoVA | 4WPI- MCCK02 | Cr-Mo-V Alloy Steel High Strength,
| Minimum temperature per ASME B31.3, Table A-2 is -29°C (-20°F). Maximum temperature per AP Specification is +538°C (+1000°F). See Note 1 |
| ASTM A320 Grade L7 | B1.1 B1.13M | 4WPI- MWCK05 | —– | —– | Alloy Steel High Strength | Minimum temperature per ASME B31.3, Table A-2 is -101°C (-150°F). Maximum temperature per AP Specification is +371°C (+700°F). |
| ASTM A320 Grade B8 Class 1 | B1.1 B1.13M | 4WPI- MWSK02 | —– | None | 304 Stainless Steel Low Strength | Minimum temperature per ASME B31.3, Table A-2 is -254°C (-425°F). Maximum temperature per AP Specification is +454°C (+850°F). |
| ASTM A193 Grade B8 Class 2 | B1.1 B1.13M | 4WPI- MWSK01 | GB1220 Gr. 0Cr18Ni9 | 4WPI- MCSK01 | 304 Stainless Steel Intermediate Strength | Minimum temperature per ASME B31.3, Table A-2 is -198°C (-325°F). Maximum temperature per AP Specification is +454°C (+850°F). See Note 1.
|
Note 1: Chinese Bolting Material Temperature Limits per AP Specifications are as follows: MPS 4WPI-MCCK01 Minimum temperature -100°C (-148°F) Maximum temperature +500°C (+932°F) MPS 4WPI-MCCK02 Minimum temperature -100°C (-148°F) Maximum temperature +500°C (+932°F) MPS 4WPI-MCCK04 Minimum temperature -20°C (-4°F) Maximum temperature +149°C (+300°F) MPS 4WPI-MCSK01 Minimum temperature -196°C (-321°F) Maximum temperature +525°C (+977°F)
5.2.1 NACE Service Bolt Materials – The following bolting materials are in conformance with NACE MR0175, and shall be used in sour environments within which sulfide stress cracking can occur. All the following bolting materials have a Rockwell C hardness of 22 or less.
| ASTM Bolt Material | ASME Thread Specification | Material Purchase Specifications (MPS) | Equivalent Chinese Bolt Material | Chinese Material Purchase Specifications (MPS) | Bolt Material & Strength | Min. / Max. Temperature Limits Comments/Restrictions |
| ASTM A193 Grade B7M | B1.1 B1.13M | 4WPI- MWCK03 | —– | None | Cr-0.2Mo Alloy Steel Intermediate Strength | Minimum temperature per ASME B31.3, Table A-2 is – 48°C (55°F). Maximum temperature per AP Specification is +400°C (+750°F). |
| ASTM A193 Grade B8M Class 2 | B1.1 B1.13M | 4WPI- MWSK03 | —– | None | 316 Stainless Steel Intermediate Strength | Minimum temperature per ASME B31.3, Table A-2 is – 198°C (325°F). Maximum temperature per AP Specification is +454°C (+850°F). |
| ASTM A193 Grade B8MA Class 1A | B1.1 B1.13M | 4WPI- MWSK04 | —– | None | 316 Stainless Steel Low Strength | Minimum temperature per ASME B31.3, Table A-2 is – 198°C (325°F). Maximum temperature per AP Specification is +454°C (+850°F). |
5.3 Nut Materials
| ASTM Nut Material | ASME Thread Specification | Material Purchase Specifications (MPS) | Equivalent Chinese Nut Material | Chinese Material Purchase Specifications (MPS) | Min. / Max. Temperature Limits Comments/Restrictions |
| Carbon Steel ASTM A563 Grade A | B18.2.2 | 4WPI- MWCK04 | GB/T 3098.2 Grade 6 | 4WPI- MCCK04 | Minimum temperature per ASME B31.3, Table A-2 is -29°C (-20°F). Maximum temperature per AP Specification is +149°C (+300°F). See Note 1. Use only when cast iron flanges might be encountered. |
| Carbon Steel ASTM A194 Grade 2H | B18.2.2 B18.2.6M | 4WPI- MWCK01 | GB 3077 Gr. 30CrMo | 4WPI- MCCK01 | Minimum temperature per ASME B31.3, Table A-2 is -48°C (-55°F). Maximum temperature per AP Specification is +424°C (+800°F). See Note 1. |
| C-Mo Alloy Steel ASTM A194 Grade 4 | B18.2.2 B18.2.6M | 4WPI- MWCK02 | GB 3077 Gr. 30CrMo | 4WPI- MCCK02 | Minimum temperature per ASME B31.3, Table A-2 is -101°C (-150°F). Maximum temperature per AP Specification is +538°C (+1000°F). See Note 1. |
| Alloy Steel ASTM A194 Grade 7 | B18.2.2 B18.2.6M | 4WPI- MWCK05 | —– | —– | Minimum temperature per ASME B31.3, Table A-2 is -101°C (-150°F). Maximum temperature per AP Specification is +371°C (+700°F). |
| Stainless Steel ASTM F594 Group 2 | B18.2.2 | 4API- MASK04 | —– | None | Minimum and maximum temperature limits per AP Specification is -29°C (-20°F) thru +100°C (+212°F). Use only with high density polyethylene pipe and ASTM F593 Group 2 bolts. |
| 304 Stainless Steel ASTM A194 Grade 8 | B18.2.2 B18.2.6M | 4WPI- MWSK01 or MWSK02 | GB 1220 Gr. 0Cr18Ni9 | 4WPI- MCSK01 | Minimum temperature per ASME B31.3, Table A-2 is -254°C (-425°F). Maximum temperature per AP Specification is +454°C (+850°F). See Note 1. |
Note 1: Chinese Nut Material Temperature Limits per AP Specifications are as follows: MPS 4WPI-MCCK01 Minimum temperature -100°C (-148°F) Maximum temperature +500°C (+932°F) MPS 4WPI-MCCK02 Minimum temperature -100°C (-148°F) Maximum temperature +500°C (+932°F) MPS 4WPI-MCCK04 Minimum temperature -20°C (-4°F) Maximum temperature +149°C (+300°F) MPS 4WPI-MCSK01 Minimum temperature -196°C (-321°F) Maximum temperature +525°C (+977°F)
5.3.1 NACE Service Nut Materials: The following nut materials are in conformance with NACE MR0175, and shall be used in sour environments within which sulfide stress cracking can occur. All the following nut materials have a Rockwell C hardness of 22 or less.
| ASTM Nut Material | ASME Thread Specification | Material Purchase Specifications (MPS) | Equivalent Chinese Nut Material | Chinese Material Purchase Specifications (MPS) | Min. / Max. Temperature Limits Comments / Restrictions |
| Carbon Steel ASTM A194 Grade 2HM | B18.2.2 B18.2.6M | 4WPI- MWCK03 | —– | None | Minimum temperature per ASME B31.3, Table A-2 is -48°C (-55°F). Maximum temperature per AP Specification is +400°C (+750°F). |
| 316 Stainless Steel ASTM A194 Grade 8MA | B18.2.2 B18.2.6M | 4WPI- MWSK03 & MWSK04 | —– | None | Minimum temperature per ASME B31.3, Table A-2 is -198°C (-325°F). Maximum temperature per AP Specification is +454°C (+850°F). |
5.4 Washer Materials
5.4.1 Washers shall be plain Type B narrow series austenitic stainless steel conforming to ASME B18.21.1 for all bolting material applications listed Table 1.
6. FLANGE COMBINATIONS
6.1 Various flange material and ASME and AWWA pressure class combinations have been evaluated and are compatible for the intended service of the piping specification. The approved bolting for various flange combinations is listed in Table 1.
Table 1 – Approved Bolting for Various Flange Combinations
| Studs | Nuts | Washers | ||||
| Flange Combinations | Material | ASTM Specification | Material | ASTM Specification | Material | Required |
| 1. Aluminum – Aluminum | Stainless Steel | A 320 Grade B8 Class 2 | Stainless Steel | A 194 Grade 8 TP 304 | Stainless Steel | 2 |
| 2. Aluminum – Stainless Steel | Stainless Steel | A 320 Grade B8 Class 2 | Stainless Steel | A 194 Grade 8 TP 304 | Stainless Steel | 1 |
| 3. Aluminum – 3.5-9 Nickel Steel (inside CB) | Stainless Steel | A 320 Grade B8 Class 2 | Stainless Steel | A 194 Grade 8 TP 304 | Stainless Steel | 1 |
| 4. Aluminum – Brass (4API-57904- Special) (ASME B16.5 Class 150 and 300 flanges only) | Stainless Steel | A 320 Grade B8 Class 2 | Stainless Steel | A 194 Grade 8 TP 304 | Stainless Steel | 2 |
| 5. Brass – Brass (4API-57904 – Special) | Stainless Steel | A 320 Grade B8 Class 2 | Stainless Steel | A 194 Grade 8 TP 304 | Stainless Steel | 2 |
| 6. Carbon Steel – Carbon Steel | Alloy Steel | A 193 Grade B7 | Carbon Steel | A 194 Grade 2H | — | 0 |
| 7. Carbon Steel – Aluminum | Alloy Steel | A 193 Grade B7 | Carbon Steel | A 194 Grade 2H | Stainless Steel | 1 |
| 8. Carbon Steel – Aluminum (Large Diameter Class 125 and AWWA C207, Table 3, Class E) | Alloy Steel | A 193 Grade B7 | Carbon Steel | A 194 Grade 2H | Stainless Steel | 1 |
| 9. Carbon Steel – Carbon Steel (Large Diameter Class 125 and AWWA C207, Table 3, Class E) | Carbon Steel | A 307 Grade B | Carbon Steel | A 563 Grade A | — | 0 |
| 10. Carbon Steel – Stainless Steel | Alloy Steel | A 193 Grade B7 | Carbon Steel | A 194 Grade 2H | — | 0 |
| 11. Carbon Steel – Brass (4API-57904- Special) | Alloy Steel | A 193 Grade B7 | Carbon Steel | A 194 Grade 2H | Stainless Steel | 1 |
| 12. Carbon Steel (Class 150) – Gray Iron (Class 125) | Carbon Steel | A 307 Grade B | Carbon Steel | A 563 Grade A | — | 0 |
| 13. Light Weight Carbon Steel – Light Weight Carbon Steel (Large Diameter Class 125 Light Weight and AWWA C207, Table 2, Class D) | Carbon Steel | A 307 Grade B | Carbon Steel | A 563 Grade A | — | 0 |
| 14. Light Weight Carbon Steel – Light Weight Carbon Steel (Large Diameter Class 125) | Carbon Steel | A 307 Grade B | Carbon Steel | A 563 Grade A | — | 0 |
| 15. Monel – Monel | Alloy Steel | A 193 Grade B7 | Carbon Steel | A 194 Grade 2H | — | 0 |
| 16. Stainless Steel – Stainless Steel (ASME B16.5 Class 150 and 300 flanges only) | Stainless Steel | A 320 Grade B8 Class 2 | Stainless Steel | A 194 Grade 8 TP 304 | — | 0 |
| 17. Stainless Steel – Stainless Steel (ASME B16.5 Class 400 up to and including Class 1500 flanges) | Stainless Steel | A 320 Grade B8 Class 2 | Stainless Steel | A 194 Grade 8 TP 304 | — | 0 |
| 18. Stainless Steel – 3.5-9 Nickel Steel (ASME B16.5 Class 150 and 300 flanges only) | Stainless Steel | A 320 Grade B8 Class 2 | Stainless Steel | A 194 Grade 8 TP 304 | — | 0 |
| 19. Stainless Steel – 3.5-9 Nickel Steel (ASME B16.5 Class 400 up to and including Class 1500 flanges) | Stainless Steel | A 320 Grade B8 Class 2 | Stainless Steel | A 194 Grade 8 TP 304 | — | 0 |
| 20. Stainless Steel – Brass (4API-57904- Special) (ASME B16.5 Class 150 and 300 flanges only) | Stainless Steel | A 320 Grade B8 Class 2 | Stainless Steel | A 194 Grade 8 TP 304 | Stainless Steel | 1 |
7. stud-bolt lengths
7.1 Stud bolts 38 mm (1½ in) in diameter and larger will be tightened using a hydraulic bolt tensioner and additional bolt length is required. The required additional bolt length is equal to 1 bolt diameter and this value shall be added to tabulated bolt length or the calculated bolt length as determined per ASME B16.5, Annex F.
7.2 When flange stud bolts are used to secure other items, it might be necessary to increase the length of the stud bolts to ensure that all threads of the nuts are fully engaged with bolt threads.
7.3 When selecting studs for insulating flanges, 15 mm (½ in) must be added to the calculated lengths.