フランジは、配管システムに不可欠なコンポーネントです, パイプを接続するための機械的コネクタとして機能します, バルブ, パンプス, およびその他の機器. 安全なサービスを提供します。, 漏れ防止接続を実現しながら、簡単に分解可能, 検査, and maintenance. Flanges are used in industries such as oil and gas, 化学処理, 水処理, 発電, 造船, and HVAC systems. To ensure proper application and performance, flanges are classified into several types based on their structure, 接続方法, 圧力定格, and application environment. This article provides a detailed classification of commonly used flanges, offering insight into their features, 利点, and typical uses.

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1. Classification by Connection Method

溶接ネックフランジ

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.

利点:

• Excellent strength and fatigue resistance

• Smooth bore transition reduces turbulence

• Ideal for repeated bending and temperature cycles

アプリケーション: 石油とガスのパイプライン, 化学プラント, high-pressure steam lines.

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スリップオンフランジ

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.

利点:

• Simple installation and alignment

• Lower initial cost than weld neck flanges

• Suitable for applications with limited space

アプリケーション: 水処理システム, HVAC piping, low-pressure industrial lines.

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ソケット溶接フランジ

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, 高圧配管.

利点:

• Smooth bore flow path

• 高圧に適しています, small-size pipelines

• Good fatigue strength

アプリケーション: Hydraulic systems, chemical process piping, high-pressure gas distribution.

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ねじ付きフランジ

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

利点:

• 溶接は不要です

• Suitable for flammable environments where welding is hazardous

• Easy to install and remove

アプリケーション: 防火システム, ユーティリティライン, compressed air piping.

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ラップジョイントフランジ

重ね継手フランジはスタブエンドで使用されます, allowing the flange to rotate freely for easy bolt alignment. They are often used in systems requiring frequent disassembly.

利点:

• 設置時の位置合わせが簡単

• Reusable in different piping assemblies

• Ideal for systems subject to frequent maintenance

アプリケーション: 食品加工, 製薬工場, 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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ブラインドフランジ

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

利点:

• Allows access for inspection and cleaning

• Can be installed or removed without disturbing the piping system

• Available in high-pressure ratings

アプリケーション: Pressure vessel closures, pipeline isolation points, maintenance access ports.

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2. Classification by Face Type

盛り上がった顔 (RF)

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

アプリケーション: 石油とガス, 化学処理, 給水システム.

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平面 (FF)

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

アプリケーション: 水処理, low-pressure applications, non-metallic piping.

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リング型ジョイント (RTJ)

Uses a metal ring gasket to achieve a high-integrity seal for high-pressure, 高温用途.

アプリケーション: Refinery equipment, high-pressure steam lines, offshore oil platforms.

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タング・アンド・グルーブ (T&G)

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

アプリケーション: Specialty chemical processing, high-integrity sealing systems.

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3. Classification by Pressure Rating

ASME Pressure Classes

• クラス 150

• クラス 300

• クラス 600

• クラス 900

• クラス 1500

• クラス 2500

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

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EN / DIN PN Ratings

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

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JIS Pressure Ratings

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

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4. Classification by Manufacturing Method

鍛造フランジ

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

アプリケーション: 高圧パイプライン, offshore structures, 発電所.

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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.

アプリケーション: Water systems, low-pressure chemical processing.

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プレートフランジ

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

アプリケーション: Low-pressure piping, ventilation systems.

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5. Special Purpose Flanges

オリフィスフランジ

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

アプリケーション: Flow measurement in oil, ガス, and water pipelines.

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メガネブラインドフランジ

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

アプリケーション: Maintenance operations, system isolation in refineries and chemical plants.

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径違いフランジ

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

アプリケーション: Space-constrained piping layouts, 改修プロジェクト.

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Importance of Choosing the Right Flange Type

The correct flange classification ensures safety, 互換性, and performance in the intended application. Mismatched flange types can lead to leaks, pressure loss, 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. 一般的な標準には次のものがあります。:

• ASME B16.5 (管フランジおよびフランジ付継手)

• ASME B16.47 (大径スチールフランジ)

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

• JIS B2220 (Japanese Industrial Standard for Flanges)

メーカーのような ササフランジ produce flanges in compliance with these standards to guarantee performance in diverse applications.

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結論

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, 顔のタイプ, 圧力定格, 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, 安全性, and cost-effectiveness in their piping systems. Partnering with experienced manufacturers like ササフランジ ensures that flanges are produced to precise specifications, ready to perform in even the most demanding environments.