ASME SA266 Gr.2N Tube Side Flange
ASME SA266 Gr.2N tube side flange is an economical and reliable medium and low pressure carbon steel connection solution suitable for non-corrosive working conditions. Tube Side Flange is used on the tube side of pressure vessels or heat exchangers to connect pipes or tube bundles and needs to withstand internal medium pressure and temperature.
Typical structure: welded neck flange (WN), slip-on flange (SO) or blind flange (BL), the specific type depends on the equipment design. Gr.2N has no significant corrosion resistance. If the medium contains sulfur or acidic components, it needs to be lined or replaced with stainless steel (such as SA182 F304).
Chemical Composition Requirements
| Item | Chemical Req. for ASTM A266, % | ||
| Gr. 1 & 2 | Gr. 3 | Gr. 4 | |
| C | ≤ 0.30 | ≤ 0.35 | ≤ 0.30 |
| Mn | 0.40~1.05 | 0.80~1.35 | 0.80~1.35 |
| P | ≤ 0.025 | ≤ 0.025 | ≤ 0.025 |
| S | ≤ 0.025 | ≤ 0.025 | ≤ 0.025 |
| Si | 0.15~0.35 | 0.15~0.35 | 0.15~0.35 |
Mechanical Properties
| Tensile Requirements |
Gr. 1 | Gr. 2 & 4 | Gr. 3 |
| T.S min. ksi [Mpa] |
60~85 [415~585] |
70~95 [485~655] |
75~100 [515~690] |
| Y.S min. ksi [Mpa] |
30 [205] |
36 [250] |
37.5 [260] |
| EL. in 2" or [62.5 mm] min. % |
23 [21] |
20 [18] |
19 [17] |
| R.o.A min. % |
38 | 33 | 30 |
| ASTM A266 Grade |
Brinell Hardness HBW |
| 1 | 121~170 |
| 2 | 137~197 |
| 3 | 156~207 |
| 4 | 137~197 |
ASME SA266 Gr.2N Tube Side Flange Application
Heat exchanger: The tube flange connects the tube bundle and the shell, which needs to withstand cyclic thermal stress.
Reactor: Sealed connection under high-pressure reaction medium.
Petrochemical equipment: Pipeline system for transporting oil, gas or corrosive fluids in refineries.
