A GOST flange refers to a type of flange that conforms to the standards set by GOST, which is a set of technical standards maintained by the Euro-Asian Council for Standardization, Metrology, and Certification (EASC). GOST standards were originally developed by the Soviet Union and are still widely used in Russia and other CIS countries.
GOST flanges are used in piping systems to connect pipes, valves, pumps, and other equipment to form a piping system. They provide easy access for cleaning, inspection, or modification. The flanges are typically made from various materials, including carbon steel, stainless steel, and other alloys, depending on the application and the fluid being transported.
Standards
GOST 12820-80: It's a common standard for GOST flanges, covering general requirements of flanges in aspects like dimensions and connection forms.
GOST 28919-1991: Applies to flange connections of wellhead equipment, specifying types, basic parameters and dimensions.
Specifications
Dimensions: The flange size ranges from ½” NB to 48” NB. There are clear regulations on specific dimensions like outer diameter, bolt hole diameter, and flange thickness corresponding to different nominal diameters.
Pressure Ratings: Usually have pressure ratings of 6 bar, 10 bar, 16 bar, 25 bar, 40 bar, etc, corresponding to classes like 150 lbs, 300 lbs, 600 lbs, 900 lbs, 1500 lbs, 2500 lbs.
Face Types: Include flat face (FF), raised face (RF), ring joint face (RTJ), lap joint face, male and female face (M&F), tongue and groove face (T&G).
Testing and Certification: Require hydrostatic testing, and material test certificates are needed as per EN 10204 3.2 and EN 10204 3.1. There are also requirements for 100% radiography test reports and third-party inspection reports.
Carbon Steel: Grades: 20, 25, 35, 45, St20, St35, St45. Properties: Good strength, durability, cost-effective.
Stainless Steel: Grades: 12X18H10T (AISI 321), 08X18H10 (AISI 304), 10X17H13M2T (AISI 316). Properties: Excellent corrosion, high strength, heat resistance.
Alloy Steel: Grades: 15X5M, 12X1MF, 10X9MFB. Properties: High strength, high-temperature, high-pressure resistance.
Low-Temperature Steel: Grades: 09G2S, 10G2. Properties: Good toughness, performance at low temperatures.
Duplex and Super Duplex Steel: Grades: 08X23H6M3 (Duplex), 03X25H6M3 (Super Duplex). Properties: High corrosion resistance, high strength.
Nickel Alloys: Grades: Monel (Ni-Cu), Inconel (Ni-Cr), Hastelloy (Ni-Mo). Properties: Excellent resistance to extreme temperatures, corrosion, oxidation.
Oil and Gas: GOST flanges connect pipes in exploration, production, and transportation, handling high - pressure fluids.
Petrochemical: Used in petrochemical plants for processes, withstanding corrosive chemicals and high temps.
Power Generation: Applied in thermal and nuclear plants, crucial for steam, water, and fuel pipelines.
Water & Wastewater: Connect pipes in treatment plants, ensuring proper system function and pollution prevention.
Marine & Shipbuilding: Used in ship's piping, resisting seawater corrosion and ship - related stresses.
Chemical: Connect pipes in various chemical industries, having excellent chemical resistance.
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