This specification covers forged carbon and alloy steel flanges intended primarily for petroleum and gas pipelines in areas subject to low ambient temperatures. Included are flanges to specified dimensions or to dimensional standards such as those MSS, ASME, and API specifications that are referenced in Section 2. 1.2 Supplementary requirements are provided for use when additional requirements are desired. These shall apply only when specified individually by the purchaser in the order. 1.3 Eight grades, four yield-strength classes, and three different notch toughness levels are included. 1.4 The availability of a particular size of flange of a specific grade and class is limited only by the capability of the composition to meet the specified mechanical property requirements. However, current practice normally limits the following: (a) Grade L1 to Classes 1 and 2, (b) Grade L2 to Classes 1, 2, and 3, (c) Grade L3 to Classes 1, 2, and 3, (d) Grade L4 to Classes 1, 2, and 3, (e) Grade L7 to Classes 1 and 2, and (f) Grades L5, L6, and L8 are generally available in any class.
| Elements | Grade | |||||||
|---|---|---|---|---|---|---|---|---|
| L1A | L2A | L3 | L4 | L5 | L6 | L7B | L8 | |
| Carbon, max, % | ||||||||
| Heat analysis | 0.20 | 0.30 | 0.22 | 0.18 | 0.07 | 0.07 | 0.20 | 0.20 |
| Product analysis | 0.23 | 0.33 | 0.25 | 0.20 | 0.09 | 0.09 | 0.22 | 0.22 |
| Manganese,% | ||||||||
| Heat analysis | 0.60-1.50 | 0.60-1.35 | 1.15-1.50 | 0.45-0.65 | 0.40-0.70 | 1.85-2.20 | 0.90 max | 0.20-0.40 |
| Product analysis | 0.55-1.60 | 0.55-1.45 | 1.05-1.60 | 0.40-0.70 | 0.35-0.75 | 1.75-2.30 | 1.00 max | 0.15-0.45 |
| Phosphorus, max, % | ||||||||
| Heat analysis | 0.030 | 0.030 | 0.025 | 0.025 | 0.025 | 0.025 | 0.025 | 0.020 |
| Product analysis | 0.035 | 0.035 | 0.030 | 0.030 | 0.030 | 0.030 | 0.030 | 0.025 |
| Sulfur, max,% | ||||||||
| Heat analysis | 0.030 | 0.030 | 0.025 | 0.025 | 0.025 | 0.025 | 0.025 | 0.020 |
| Product analysis | 0.040 | 0.040 | 0.035 | 0.035 | 0.035 | 0.035 | 0.035 | 0.025 |
| Silicon, max, % | ||||||||
| Heat analysis | 0.35 | 0.35 | 0.30 | 0.35 | 0.35 | 0.15 | 0.35 | 0.35 |
| Product analysis | 0.37 | 0.37 | 0.32 | 0.37 | 0.37 | 0.17 | 0.37 | 0.37 |
| Chromium,% | ||||||||
| Heat analysis | 0.30 max | 0.30 max | 0.30 max | 0.30 max | 0.60-0.90 | 0.30 max | 0.30 max | 1.50-2.00 |
| Product analysis | 0.34 max | 0.34 max | 0.34 max | 0.34 max | 0.56-0.94 | 0.34 max | 0.34 max | 1.44-2.06 |
| Nickel,% | ||||||||
| Heat analysis | 0.40 max | 0.40 max | 0.40 max | 1.65-2.00 | 0.70-1.00 | 0.40 max | 3.2-3.7 | 2.8-3.9 |
| Product analysis | 0.43 max | 0.43 max | 0.43 max | 1.60-2.05 | 0.67-1.03 | 0.43 max | 3.18-3.82 | 2.68-3.97 |
| Molybdenum,% | ||||||||
| Heat analysis | 0.12 max | 0.12 max | 0.12 max | 0.20-0.30 | 0.15-0.25 | 0.25--0.35 | 0.12 max | 0.40-0.60 |
| Product analysis | 0.13 max | 0.13 max | 0.13 max | 0.19-D.33 | 0.14-0.28 | 0.22--0.38 | 0.13 max | 0.35-0.65 |
| Vanadium,% | ||||||||
| Heat analysis | 0.05 max | 0.05 max | 0.04-0.11 | 0.05 max | 0.05 max | 0.05 max | 0.05 max | 0.05 max |
| Product analysis | 0.06 max | 0.06 max | 0.03--0.13 | 0.06 max | 0.06 max | 0.06 max | 0.06 max | 0.06 max |
| Nitrogen, % | ||||||||
| Heat analysis | ... | ... | 0.010–0.030 | ... | ... | ... | ... | ... |
| Product analysis | ... | ... | 0.005–0.035 | ... | ... | ... | ... | ... |
| Copper, % | ||||||||
| Heat analysis | 0.40 max | 0.40 max | 0.20 mine | 0.40 max | 1.00-1.30 | 0.40 max | 0.40 max | 0.40 max |
| Product analysis | 0.43 max | 0.43 max | 0.18 mine | 0.43 max | 0.95-1.35 | 0.43 max | 0.43 max | 0.43 max |
| Columbium, % | ||||||||
| Heat analysis | 0.02 max | 0.02 max | 0.02 max | 0.02 max | 0.03 min | 0.06-0.10 | 0.02 max | 0.02 max |
| Product analysis | 0.03 max | 0.03 max | 0.03 max | 0.03 max | 0.02 min | 0.05-0.11 | 0.03 max | 0.03 max |
A. The sum of copper, nickel, chromium, and molybdenum shall not exceed 1.00 % on heat analysis.
B. The sum of chromium, molybdenum and vanadium shall not exceed 0.32 % on heat analysis.
C. When specified.
| Property | Class 1 | Class 2 | Class 3 | Class 4 |
|---|---|---|---|---|
| Yield strengthA min, ksi [MPa] | 42 [290] | 52 [360] | 60 [415] | 75 [515] |
| Tensile strength, min, ksi [MPa] | 60 [415] | 66 [455] | 75 [515] | 90 [620] |
| Elongation in 2 in. or 50 mm, min, % | 22 | 22 | 20 | 20 |
| Reduction of area, min, % | 40 | 40 | 40 | 40 |
| Hardness, HBW | 149–207 | 149–217 | 156–235 | 179–265 |
| Cv energy absorption,B,C min, avg, ft·lbf [J] | 30 [41] | 40 [54] | 50 [68] | 50 [68] |
| Cv energy absorption,B,D min, ft·lbf [J] | 24 [33] | 32 [43] | 40 [54] | 40 [54] |
A. 0.2 % offset.
B. For a set of three full-size [10 by 10 mm] Charpy V-notch specimens. Acceptance
values for sub-size specimens are reduced in proportion to the reduction in width
of the specimen.
C. These requirements are intended to minimize fracture initiation. They are not
intended to give assurance against fracture propagation. If minimization of fracture
propagation is of interest, consideration should be given to specifying Supplementary Requirement S7 at the operating temperature.
D. Minimum impact energy permitted for one specimen only of a set of three
specimens.