Фланцы являются важными компонентами трубопроводных систем., serving as mechanical connectors for joining pipes, клапаны, насосы, и другое оборудование. They provide a secure, leak-proof connection while allowing for easy disassembly, инспекция, и обслуживание. Flanges are used in industries such as oil and gas, химическая обработка, очистка воды, производство электроэнергии, судостроение, and HVAC systems. To ensure proper application and performance, flanges are classified into several types based on their structure, метод подключения, номинальное давление, and application environment. This article provides a detailed classification of commonly used flanges, offering insight into their features, преимущества, and typical uses.

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1. Classification by Connection Method

Приварной фланец с горловиной

A weld neck flange features a long tapered hub that is welded to the pipe. This design transfers stress to the pipe, reducing the concentration at the base of the flange. Weld neck flanges are suitable for high-pressure, high-temperature applications where strength and durability are critical.

Преимущества:

• Excellent strength and fatigue resistance

• Smooth bore transition reduces turbulence

• Ideal for repeated bending and temperature cycles

Приложения: Нефте- и газопроводы, химические заводы, high-pressure steam lines.

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Съемный фланец

Slip-on flanges are slipped over the pipe and welded on both the inside and outside. They are easier to align than weld neck flanges and are widely used in low- to medium-pressure systems.

Преимущества:

• Simple installation and alignment

• Lower initial cost than weld neck flanges

• Suitable for applications with limited space

Приложения: Системы очистки воды, HVAC piping, low-pressure industrial lines.

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Плата сварка

This flange has a socket where the pipe is inserted before being fillet welded at the outside. Socket weld flanges are used for smaller diameter, трубопровод высокого давления.

Преимущества:

• Smooth bore flow path

• Подходит для высокого давления, small-size pipelines

• Good fatigue strength

Приложения: Гидравлические системы, chemical process piping, high-pressure gas distribution.

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Резьбовой фланец

Threaded flanges have internal threads that match the pipe threads, allowing connection without welding. They are ideal for low-pressure, non-critical applications.

Преимущества:

• Сварка не требуется

• Suitable for flammable environments where welding is hazardous

• Легко устанавливается и снимается

Приложения: Системы противопожарной защиты, инженерные коммуникации, compressed air piping.

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Коленные соединения фланца

Lap joint flanges are used with a stub end, allowing the flange to rotate freely for easy bolt alignment. They are often used in systems requiring frequent disassembly.

Преимущества:

• Легкое выравнивание во время установки

• Reusable in different piping assemblies

• Ideal for systems subject to frequent maintenance

Приложения: Пищевая промышленность, pharmaceutical plants, corrosive environments where flanges can be made from a less expensive material and the stub end from a corrosion-resistant alloy.

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Глухой фланец

A blind flange has no bore and is used to seal off the end of a piping system or pressure vessel opening.

Преимущества:

• Allows access for inspection and cleaning

• Can be installed or removed without disturbing the piping system

• Available in high-pressure ratings

Приложения: Pressure vessel closures, pipeline isolation points, maintenance access ports.

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2. Classification by Face Type

Поднятое лицо (РФ)

The most common flange facing type, the raised face has a small raised area for gasket seating, improving the sealing capability.

Приложения: Нефть и газ, химическая обработка, водные системы.

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Плоское Лицо (ФФ)

The gasket surface is in the same plane as the bolt circle face. Commonly used with cast iron equipment.

Приложения: Очистка воды, low-pressure applications, non-metallic piping.

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Кольцевое соединение типа (РТЖ)

Uses a metal ring gasket to achieve a high-integrity seal for high-pressure, высокотемпературные применения.

Приложения: Refinery equipment, high-pressure steam lines, offshore oil platforms.

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Язык и паз (Т&Г)

A male (tongue) flange fits into a female (groove) фланец, providing precise gasket positioning.

Приложения: Specialty chemical processing, high-integrity sealing systems.

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3. Classification by Pressure Rating

ASME Pressure Classes

• Сорт 150

• Сорт 300

• Сорт 600

• Сорт 900

• Сорт 1500

• Сорт 2500

The higher the class, the thicker and stronger the flange to withstand higher pressures.

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EN / DIN PN Ratings

ПН 6, ПН 10, ПН 16, ПН 25, ПН 40, ПН 63, ПН 100, ПН 160.
PN stands for nominal pressure in bars at a reference temperature.

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Номинальное давление JIS

5К, 10К, 16К, 20К, 30К.
Commonly used in Japanese and some Asian market applications.

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4. Classification by Manufacturing Method

Кованые фланцы

Produced by forging steel billets, offering superior mechanical properties and grain structure.

Приложения: Трубопроводы высокого давления, offshore structures, электростанции.

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Cast Flanges

Manufactured by casting molten metal into molds. More economical for complex shapes but may have lower mechanical strength than forged flanges.

Приложения: Water systems, low-pressure chemical processing.

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Пластинчатые фланцы

Cut from plate material and machined to specifications. Economical but generally limited to lower pressure ratings.

Приложения: Low-pressure piping, ventilation systems.

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5. Special Purpose Flanges

Фланцы с отверстиями

Designed for use with orifice meters to measure flow rate in pipelines. Includes tapped holes for pressure measurement.

Приложения: Flow measurement in oil, газ, and water pipelines.

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Фланцы для очковых заглушек

Consist of a connected pair of metal discs, one solid and one with an opening, used to isolate a section of pipe.

Приложения: Maintenance operations, system isolation in refineries and chemical plants.

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Редукционные фланцы

Allow connection between pipes of different diameters without the need for a separate reducer fitting.

Приложения: Space-constrained piping layouts, retrofit projects.

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Importance of Choosing the Right Flange Type

The correct flange classification ensures safety, совместимость, and performance in the intended application. Mismatched flange types can lead to leaks, потеря давления, or mechanical failures. Selecting the correct flange also simplifies maintenance and ensures compliance with applicable standards.

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Standards Governing Flanges

Flanges must conform to international standards to ensure quality and interchangeability. Общие стандарты включают в себя:

• ASME B16.5 (Трубные фланцы и фланцевые фитинги)

• ASME B16.47 (Стальные фланцы большого диаметра)

• EN 1092-1 (European Standard for Steel Flanges)

• JIS B2220 (Japanese Industrial Standard for Flanges)

Производителям нравится Сасафланж produce flanges in compliance with these standards to guarantee performance in diverse applications.

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Заключение

Flanges are critical components in any piping system, and understanding their classification helps in selecting the right product for specific operational requirements. Whether based on connection type, тип лица, номинальное давление, manufacturing method, or special function, each flange type serves a unique purpose.

By aligning flange selection with industry standards and application needs, engineers and procurement teams can ensure long-term reliability, безопасность, and cost-effectiveness in their piping systems. Сотрудничество с опытными производителями, такими как Сасафланж ensures that flanges are produced to precise specifications, ready to perform in even the most demanding environments.