高圧配管システムは、石油やガスなどの産業における重要なインフラストラクチャです。, 石油化学製品, 発電, と航空宇宙. これらのシステムは高温を伴う極端な条件下で動作します。, 激しいプレッシャー, and corrosive media. 結果として, each component—especially the flanged connections—must offer superior mechanical strength and leak-tight integrity. One innovative solution that enhances both safety and performance in these applications is the use of dual-flange structures.

あ dual-flange structure involves the integration of two flanges—often arranged in tandem—to reinforce the connection and distribute mechanical loads more evenly. This setup is increasingly used in high-pressure pipelines, 圧力容器, and subsea installations. この記事では, we explore the benefits, design principles, 材料, and application scenarios of dual-flange structures in high-pressure systems.

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1. What Is a Dual-Flange Structure?

あ dual-flange structure refers to the configuration where two flanges are employed together at a single joint or in close proximity to enhance:

• Pressure resistance

• Structural stability

• Vibration damping

• Sealing reliability

This can be achieved in several ways:

• 二 standard flanges bolted together for a stronger joint

• あ バッキングフランジ supporting the primary flange

• あ redundant flange system with parallel sealing for added safety

These designs are commonly found in high-pressure vessels, critical gas lines, offshore oil pipelines, そして cryogenic storage systems.

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2. Why Use Dual-Flange Structures?

Single-flange joints may be sufficient in moderate-pressure systems, but in 高圧 または dynamic environments, additional reinforcement is necessary. Dual-flange setups provide:

• Redundancy in case one flange experiences gasket failure

• Improved alignment and support for large-diameter or long-span pipelines

• Enhanced stress distribution around the joint

• Sealing reinforcement through dual-gasket configurations

• Reduced risk of flange rotation or bolt failure

で ササフランジ, we specialize in dual-flange solutions designed to withstand extreme mechanical and environmental challenges.

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3. Types of Dual-Flange Configurations

ある) Tandem Flanges

Two flanges installed back-to-back with a shared bolt circle. Often used in critical applications where a double-sealing system is required.

b) Reinforcing Flange + Primary Flange

A secondary flange is added behind the main flange to act as a structural support, preventing distortion under bending or thermal loads.

c) Double Isolation Flange Systems

Used in hazardous or toxic media handling, this setup includes two sealing surfaces separated by a bleed port to ensure zero leakage.

d) Dual-Flange Adapter Systems

Used to connect pipes of different diameters or standards (例えば, ANSI to DIN), 提供物 structural integrity and transition flexibility.

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4. Material Selection for Dual-Flange Systems

Material choice is critical in dual-flange assemblies due to the increased mechanical load and environmental exposure.

Common materials:

• 炭素鋼 (ASTM A105, A350 LF2)

• ステンレス鋼 (304, 316, 321)

• 合金鋼 (F11, F22)

• 二相ステンレス鋼 (2205, 2507)

• ニッケル合金 (インコネル, ハステロイ, モネル)

ササフランジ offers dual-flange assemblies in all standard and custom materials, fully traceable and compliant with ASME, EN, および API 標準.

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5. Design Considerations for Dual-Flange Assemblies

When engineering a dual-flange system, several factors must be considered:

• 圧力定格: Flanges should be rated for Class 600 以上

• Bolt load: Must be evenly distributed across both flanges

• Gasket compatibility: Dual-gasket setups must match the service media

• Flange face types: Can be Raised Face (RF), リング型ジョイント (RTJ), or Flat Face (FF)

• Installation clearance: Additional space required for bolts and inspection

• 熱膨張: Must accommodate dimensional changes during operation

私たちの ササフランジ engineering team works with clients to customize each dual-flange solution to specific project conditions.

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6. Applications of Dual-Flange Structures

Dual-flange systems are used where safety, パフォーマンス, and reliability cannot be compromised. 一般的なアプリケーションには次のものがあります。:

ある) High-Pressure Natural Gas Pipelines

• Long-distance gas transport under high internal pressure

• Dual flanges reduce flange movement due to pressure pulsation

b) Subsea and Offshore Installations

• Withstands underwater pressure and corrosion

• Enhances joint integrity in deep-sea environments

c) High-Temperature Steam Lines

• Used in thermal power plants and chemical reactors

• Dual flanges mitigate stress caused by thermal expansion and vibration

d) Hazardous Chemical Transport

• Dual-seal design prevents leakage of corrosive or toxic media

• Enables safe inspection and maintenance without full depressurization

e) Cryogenic Systems

• LNG pipelines and liquid hydrogen storage

• Maintains seal integrity under extreme temperature fluctuations

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7. Sealing Mechanism and Gasket Options

Dual-flange systems may use one or two gaskets, depending on configuration:

• Double gasket: Used in isolation applications with a monitoring port between gaskets

• Single gasket with backup: Secondary flange provides structural support if the primary seal fails

Gasket types include:

• うず巻形ガスケット

• RTJ (リング型ジョイント) ガスケット

• カムプロファイルガスケット

• Metal-jacketed gaskets

Gasket material must match both the fluid and the temperature/pressure profile of the system.

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8. Standards and Codes

While dual-flange configurations are not always specified in public codes, they are often designed to comply with:

• ASME B16.5 / B16.47

• API 6A / API 6D

• MSS SP-44

• EN 1092-1

• ISO 7005

全て ササフランジ dual-flange systems can be delivered with:

• EN 10204 3.1/3.2 材料証明書

• Non-destructive testing (NDT) reports

• Hydrostatic and pneumatic test results

• Dimensional inspection records

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9. Advantages of Dual-Flange Structures