Product Introduction

Large diameter high-pressure flange refers to a flange connection with a larger nominal diameter (DN) that can withstand higher pressure. It is usually used to connect high-pressure pipelines, valves, pumps, and other equipment with large pipe diameters.

Large caliber high-pressure flanges follow various domestic and international standards, such as national standards GB/T 9115-2020 "Flat Welded Steel Pipe Flanges with Neck", GB/T 9116-2020 "Welded Steel Pipe Flanges with Neck", industry standards HG/T 20592-2009 "Steel Pipe Flanges (PN Series)", SH/T 3406-2013 "Petrochemical Steel Pipe Flanges", as well as international standards ANSI B16.5-2023 (American Standard), DIN 2501-2022 (German Standard), etc.

Specifications

Nominal diameter: Common specifications are DN500-DN4000, used to connect pipelines for high flow transportation.

Nominal pressure: High pressure levels, such as PN64 (6.4MPa), PN100 (10.0MPa), PN160 (16.0MPa), and even higher pressure levels.

Other dimensions: As the nominal diameter and nominal pressure increase, the outer diameter of the flange, the diameter of the bolt hole center circle, the number of bolt holes, the thickness of the flange, and other dimensions also increase accordingly to ensure sealing compression force and structural strength.

Structure and Materials

Structural types: Neck welded flanges, integral flanges, and other structures are commonly used. The neck or integral design enhances the rigidity and impact resistance of the flange, which can better withstand high pressure.

Material selection: High quality materials such as carbon steel, stainless steel, and alloy steel are usually selected. For special working conditions such as high corrosion resistance requirements, Hastelloy alloy, titanium alloy, etc. may be used. In low-temperature environments, 9% nickel steel may be used.

Sealing form

There are multiple sealing surfaces to choose from, such as protruding surfaces (RF), suitable for general working conditions; Ring connection surface (RTJ), used in high-pressure, high-temperature, or hazardous medium applications, can be paired with metal octagonal or elliptical gaskets to achieve reliable sealing; Full Flat (FF), generally used for flanges made of materials such as cast iron or fiberglass.

Application field

Petroleum and natural gas industry: used for connecting long-distance pipelines and gathering systems for crude oil and natural gas, as well as equipment such as reactors and heat exchangers in refining and chemical plants.

Energy and power industry: It is applied in the main steam pipelines of thermal power and nuclear power, as well as in the hydraulic systems of wind power and hydropower equipment, and in the inlet and outlet pipelines of water turbines.

In the field of chemical and pharmaceutical industry, it can be used for connecting the inlet and outlet of corrosive medium transportation pipelines, as well as high-pressure reaction vessels, evaporators and other equipment.

Ocean and Ship Engineering: Suitable for the connection of subsea pipelines and platform equipment on offshore oil platforms, as well as the connection of low-temperature liquid cargo tanks and cargo pumps on LNG transport ships.