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Product Overview
Alloy Steel Flanges
An alloy steel flange system (weld neck, slip-on, blind, socket weld, threaded, lap joint), 1/2-48 inch, Class 150-2500, ASTM A182 F5/F9/F11/F22.
Product Introduction
1. Main Product Types
- Weld Neck Flange (WN), Slip On Flange (SO), Blind Flange (BL), Socket Weld Flange (SW)
- Threaded Flange (NPT), Lap Joint Flange (LJ), Orifice Flange, Long Weld Neck Flange, Reducing Flange
- Face types: Raised Face (RF), Ring Type Joint (RTJ), Flat Face (FF), Male & Female (M&F)
- Manufacturing process: Forged, machined, heat-treated (normalizing, tempering, annealing, quenching), full NDT inspection
- Surface treatment: Black anti-rust coating, shot blasting, phosphating, anti-rust oil, epoxy coating
2. Executive Standards
Dimensional & Design Standards
- ASME B16.5: Pipe Flanges and Flanged Fittings (NPS 1/2” ~ NPS 24”)
- ASME B16.47: Large Diameter Steel Flanges (NPS 26” ~ NPS 60”, Series A / B)
- ASME B31.1: Power Piping
- ASME B31.3: Process Piping
- ASME B31.8: Gas Transmission Piping Systems
- MSS SP-44: Steel Line Pipe Flanges
- API 605: Large Diameter Carbon Steel Flanges
- EN 1092-1: Flanges and their joints – Circular flanges for pipes, valves, fittings
- ASME BPVC Section I / Section VIII: Boiler & Pressure Vessel Code
- NACE MR0175 / ISO 15156: Sour Oil & Gas Service
Material & Test Standards
- ASTM A182/A182M: Forged or Rolled Alloy Steel Pipe Flanges for High-Temperature Service
- ASTM A961/A961M: Common Requirements for Wrought Steel Piping Flanges and Fittings
- ASTM A707/A707M: Forged Alloy Steel Flanges for Low-Temperature Gas Pipeline Service
- ASTM A350/A350M: Carbon and Alloy Steel Forgings for Low-Temperature Piping Components
- ISO 9001: Quality Management System
- NDT standards: ASME BPVC, ASTM E165, ASTM E709, ASTM E1416
- Hydrostatic & leak test: ASME B16.5, ASME B16.47
3. Main Materials
Common Alloy Steel Grades
-
ASTM A182 F11 (1.25Cr-0.5Mo)
- Moderate high-temperature steam and process piping, general power plant service
-
ASTM A182 F22 (2.25Cr-1Mo)
- Heavy high-temperature refinery and power piping, excellent creep resistance
-
ASTM A182 F5 (5Cr-0.5Mo)
- High-temperature hydrocarbon & hydrogen processing systems
-
ASTM A182 F9 (9Cr-1Mo)
- Severe high-temperature refining and coker piping systems
-
ASTM A182 F91 (9Cr-1Mo-V / P91)
- Ultra-supercritical power boilers, ultra-high temperature steam piping
-
ASTM A707, A350 LF series
- Low-temperature alloy steel flanges for cold service, LNG & cold pipeline systems
Material Features
- Chromium-molybdenum ferritic alloy steel, controlled heat treatment for stable microstructure
- High temperature creep strength, hydrogen corrosion resistance, sulfide stress cracking resistance
- Full traceability of heat numbers, chemical analysis and mechanical test records
4. General Specification Parameters Table
| Item | Specification |
|---|---|
| Product Name | Alloy Steel Forged Pipe Flanges, Cr-Mo Alloy Steel Flanges |
| Flange Types | WN, SO, BL, SW, NPT Threaded, LJ, Orifice, Reducing Flange |
| Flange Face | RF (Raised Face), RTJ (Ring Type Joint), FF (Flat Face), M&F |
| Nominal Size | NPS 1/2" ~ NPS 60" / DN15 ~ DN1500 (custom sizes available) |
| Pressure Class | Class 150, 300, 600, 900, 1500, 2500, 4500, 6000 / PN16 ~ PN420 |
| Material Grades | A182 F11, F22, F5, F9, F91; A707; A350 LF series |
| Operating Temperature | -45°C ~ +620°C (depends on alloy grade and heat treatment) |
| Manufacturing Process | Forging, CNC machining, heat treatment (normalizing / tempering / quenching) |
| Surface Finish | Black anti-rust paint, shot blasting, anti-rust oil, epoxy coating |
| Typical Application | Thermal power plants, refineries, petrochemical plants, hydrogen processing, high-temperature steam pipelines, sour gas & oil pipelines |
| Inspection & Test | PMI verification, chemical analysis, tensile/hardness/impact test, NDT (UT/MT/PT/RT), hydrostatic pressure test, hardness check |
| Certification | ISO9001, PED, API, BV, DNV, LR, EN 10204 3.1 / 3.2 MTC |