ASTM A387 Alloy Steel Flange, Grade 7, Class 1

1,We Manufacturing processes are primarily classified into four types: 1:Forging, 2:Casting, 3:Cutting, 4:Rolling. 2,We can manufacture in accordance with these standards. Standards: GB Series (Chinese Standards), JB Series (Machinery Standards), HG Series (Chemical Industry Standards), ASME B16.5 (American Standards), BS4504 (British Standards), DIN (German Standards), and JIS (Japanese Standards). Internationally, there are two primary systems of pipe flange standards: the European system, represented by the German DIN standards (including those of the former Soviet Union), and the American system, represented by the US ANSI pipe flange standards. Other common standards include: the Chinese Ministry of Machinery Industry standards (JB series), the Ministry of Chemical Industry standards (HG series), the Chinese National Standard *GB/T 9112–9124-2010 Steel Pipe Flanges*, as well as US standards (ASME B16.5), British standards (BS4504), German standards (DIN), Japanese standards (JIS), and marine standards (CBM), among others. The nominal pressure ratings for the PN series are designated by "PN" and comprise the following nine levels: PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100, and PN160. The nominal pressure ratings for the Class series are designated by "Class" and comprise the following six levels: Class150, Class300, Class600, Class900, Class1500, and Class2500. Flange Classification 1. **According to Chemical Industry Standards:** Flanges are classified as follows: Plate Flat Welding Flange (PL), Necked Flat Welding Flange (SO), Necked Butt Welding Flange (WN), Integral Flange (IF), Socket Welding Flange (SW), Threaded Flange (Th), Butt Welding Ring Loose Flange (PJ/SE), Blind Flange (BL), Flat Welding Ring Loose Flange (PJ/PJ), and Lined Blind Flange (BL(s)). 2. **According to Petrochemical (SH) Industry Standards:** Flanges are classified as follows: Threaded Flange (PL), Butt Welding Flange (WN), Flat Welding Flange (SO), Socket Welding Flange (SW), Loose Flange (LJ), and Blind Flange (no specific designation). 3. **According to Machinery (JB) Industry Standards:** Flanges are classified as follows: Integral Flange, Butt Welding Flange, Plate Flat Welding Flange, Butt Welding Ring Plate Loose Flange, Flat Welding Ring Plate Loose Flange, Lap Joint Ring Plate Loose Flange, and Blind Flange. 4. **According to Connection Method/Type:** Flanges are classified as follows: Plate Flat Welding Flange, Necked Flat Welding Flange, Necked Butt Welding Flange, Socket Welding Flange, Threaded Flange, Blind Flange, Necked Butt Welding Ring Loose Flange, Flat Welding Ring Loose Flange, Ring-Type Joint (RTJ) Flange and Blind Flange, Large-Diameter Plate Flange, Large-Diameter High-Neck Flange, Figure-8 Blind Plate, Butt Welding Ring Loose Flange, etc. 5. **According to the Component Being Connected:** Flanges can be classified into Vessel Flanges and Pipe Flanges. 6. **According to Structural Type:** Flanges include Integral Flanges, Threaded Flanges, Flat Welding Flanges, Butt Welding Flanges, Lap Joint (Loose/Swivel) Flanges, and Blind Flanges. A flange—also referred to as a flange plate or rim—is a component used to connect shafts to one another, or, more commonly, to join the ends of pipes. Flanges are also utilized at the inlet and outlet ports of equipment to facilitate connections between two devices—for instance, the flange on a speed reducer. A "flange connection" or "flanged joint" refers to a detachable joint assembly comprising three interconnected elements—a flange, a gasket, and bolts—that together form a sealed structural unit. In the context of piping systems, a "pipe flange" specifically denotes a flange used for plumbing within the installation; when applied to equipment, it refers to the inlet or outlet flange of that specific device. Flanges feature a series of holes through which bolts are inserted to securely fasten the two flanges together, while a gasket placed between the flanges ensures a leak-proof seal. Flanges are broadly categorized into three types: threaded (screw-in) flanges, welded flanges, and clamp-type flanges. Flanges are invariably used in pairs; threaded flanges are suitable for low-pressure piping applications, whereas welded flanges are required for systems operating at pressures exceeding 4 kilograms per square centimeter. A sealing gasket is inserted between the two flange plates, which are then firmly secured using bolts. The thickness of a flange—as well as the specifications of the bolts used to fasten it—vary depending on the specific pressure rating required for the application. When connecting equipment such as water pumps or valves to piping systems, the corresponding connection points on these devices are often manufactured in the shape of a matching flange; this method of attachment is also referred to as a "flange connection." Generally, any connecting component that utilizes bolts to join and seal the perimeters of two flat surfaces—such as the joints in ventilation ducts—is termed a "flange"; such components may collectively be classified as "flange-type parts." However, since such a connection often constitutes merely a *portion* of a larger device—for instance, the interface between a flange and a water pump—it would be inappropriate to classify the entire water pump itself as a "flange-type part." Conversely, smaller components—such as valves—that feature such flanged interfaces may indeed be appropriately categorized as "flange-type parts." -:- For detailed product information, please contact sales. -: ASTM A387 Alloy Steel Flange, Grade 7, Class 1 Product Information -:- For detailed product information, please contact sales. -: ASTM A387 Alloy Steel Flange, Grade 7, Class 1 Synonyms -:- For detailed product information, please contact sales. -:

ASTM A387 Alloy Steel, Grade 7, Class 1 Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: ASTM A387 Grade 7 Class 1 Steel** **ASTM A387 Grade 7 Class 1** is a chromium-molybdenum alloy steel plate designed for pressure vessel applications requiring excellent elevated temperature strength and superior corrosion resistance. This specification covers plates in the annealed or normalized and tempered condition, suitable for welded pressure vessels operating in severe high-temperature environments. --- #### **1. International Standards & Classification** **Primary Standard:** **ASTM A387/A387M** - "Standard Specification for Pressure Vessel Plates, Alloy Steel, Chromium-Molybdenum" **Grade Classification:** - **Grade 7** - 7.0% Chromium - 0.5% Molybdenum alloy steel - **Class 1** - Annealed or normalized and tempered condition **International Equivalents:** - **EN 10028-2**: X12CrMo7 - **JIS G4109**: SCMV 9 - **GB/T 3077**: 50Cr7MoSiV - **ISO 9328-2**: X12CrMo7 --- #### **2. Chemical Composition** The chemical composition requirements for ASTM A387 Grade 7: | Element | Composition (Maximum %) | |---|---| | Carbon (C) | 0.15 | | Manganese (Mn) | 0.30-0.60 | | Phosphorus (P) | 0.035 | | Sulfur (S) | 0.035 | | Silicon (Si) | 0.50-1.00 | | Chromium (Cr) | 6.00-8.00 | | Molybdenum (Mo) | 0.45-0.65 | **Key Composition Features:** - **High Chromium Content**: 6.00-8.00% for exceptional oxidation and corrosion resistance - **Molybdenum Addition**: 0.45-0.65% for enhanced creep strength - **Controlled Carbon**: Maximum 0.15% for weldability and toughness - **Silicon Enhancement**: 0.50-1.00% for improved high-temperature strength --- #### **3. Physical & Mechanical Properties** **Mechanical Properties (Class 1 condition):** | Property | Value | |---|---| | **Tensile Strength** | 515-690 MPa (75-100 ksi) | | **Yield Strength (min.)** | 310 MPa (45 ksi) | | **Elongation in 2" (min.)** | 18% | | **Elongation in 8" (min.)** | 20% | **Elevated Temperature Properties:** - **Maximum Service Temperature**: Up to 700°C (1290°F) - **Creep Strength**: Excellent resistance to creep deformation - **Oxidation Resistance**: Superior performance in high-temperature oxidizing atmospheres - **Sulfidation Resistance**: Outstanding resistance to sulfur attack **Physical Properties:** - **Density**: 7.75 g/cm³ (0.280 lb/in³) - **Modulus of Elasticity**: 205 GPa (29,700 ksi) - **Thermal Conductivity**: 32.5 W/m·K - **Coefficient of Thermal Expansion**: 10.8 × 10⁻⁶/°C - **Specific Heat Capacity**: 450 J/kg·K --- #### **4. Product Applications** **High-Temperature Pressure Vessels:** - Hydrocracking reactors - Catalytic reforming units - High-temperature hydrogen vessels - Severe service refinery equipment **Power Generation:** - High-temperature boiler components - Steam cracking tubes - Advanced heat exchanger systems - High-pressure high-temperature piping **Petrochemical Industry:** - Ethylene production equipment - High-temperature reactors - Petrochemical processing vessels - Refinery conversion units **Special Applications:** - Synthetic fuel processing equipment - High-temperature chemical reactors - Advanced energy systems - High-corrosion service equipment --- #### **5. Fabrication Characteristics** **Welding Performance:** - **Fair Weldability**: Requires careful procedure control - **Preheat Requirements**: 250-350°C (480-660°F) minimum - **Post-Weld Heat Treatment**: Mandatory at 730-760°C (1350-1400°F) - **Recommended Processes**: GTAW, SMAW (low-hydrogen) - **Filler Metals**: E505-XX, E7Cr-XX or equivalent **Forming & Machining:** - **Moderate Formability**: Hot forming required for complex shapes - **Machinability**: Fair (approximately 40% of B1112 steel) - **Cutting Methods**: Plasma and waterjet cutting recommended - **Hot Working Temperature**: 1050-1150°C (1920-2100°F) **Heat Treatment:** - Supplied in annealed or normalized and tempered condition - Normalizing temperature: 950-980°C (1740-1800°F) - Tempering temperature: 700-750°C (1290-1380°F) - Annealing temperature: 850-880°C (1560-1615°F) **Quality Assurance:** - **Comprehensive Testing**: Full mechanical and chemical analysis - **Impact Testing**: Required for pressure vessel applications - **Hardness Testing**: Mandatory quality control - **Non-Destructive Testing**: UT, RT, MT as specified --- ### **Technical Summary** ASTM A387 Grade 7 Class 1 represents an advanced chromium-molybdenum alloy steel offering exceptional high-temperature corrosion resistance and mechanical properties. The 7% chromium content provides outstanding resistance to oxidation, sulfidation, and other high-temperature corrosive environments, making it suitable for the most severe service conditions in refinery and petrochemical applications. This grade demonstrates superior performance in applications involving high-temperature hydrogen service, sulfur-containing atmospheres, and other aggressive corrosive media. The material's enhanced chromium content significantly improves its resistance to high-temperature scaling and corrosive attack compared to lower chromium grades, while the molybdenum addition ensures excellent creep strength and thermal stability. Grade 7 Class 1 is particularly valuable for hydrocracking reactors, catalytic reforming units, and other high-temperature processing equipment where both mechanical integrity and corrosion resistance are critical requirements. The material's ability to withstand temperatures up to 700°C (1290°F) while maintaining good mechanical properties makes it ideal for advanced energy systems and high-temperature chemical processing applications. While requiring sophisticated fabrication techniques and stringent quality controls, ASTM A387 Grade 7 Class 1 delivers reliable performance in the most demanding high-temperature, high-pressure service conditions. Its proven track record in severe service applications has established it as a premium material choice for engineers designing pressure vessels and process equipment for extreme operating environments in the petroleum refining, chemical processing, and power generation industries. -:- For detailed product information, please contact sales. -: ASTM A387 Alloy Steel, Grade 7, Class 1 Specification Dimensions Size： Diameter 20-1000 mm Length <4374 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: ASTM A387 Alloy Steel, Grade 7, Class 1 Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A387 Alloy Steel Flange, Grade 7, Class 1 -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A387 Alloy Steel Flange, Grade 7, Class 1 -:- For detailed product information, please contact sales. -:

Packing of ASTM A387 Alloy Steel Flange, Grade 7, Class 1 -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Flange drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 845 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition