الشفاه هي مكونات أساسية في أنظمة الأنابيب, بمثابة موصلات ميكانيكية لربط الأنابيب, الصمامات, مضخات, وغيرها من المعدات. أنها توفر آمنة, اتصال مانع للتسرب مع السماح بسهولة التفكيك, تقتيش, والصيانة. Flanges are used in industries such as oil and gas, المعالجة الكيميائية, معالجة المياه, توليد الطاقة, بناء السفن, and HVAC systems. To ensure proper application and performance, flanges are classified into several types based on their structure, طريقة الاتصال, تصنيف الضغط, and application environment. This article provides a detailed classification of commonly used flanges, offering insight into their features, المزايا, and typical uses.

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1. Classification by Connection Method

شفة الرقبة اللحام

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.

المزايا:

• Excellent strength and fatigue resistance

• Smooth bore transition reduces turbulence

• Ideal for repeated bending and temperature cycles

التطبيقات: خطوط أنابيب النفط والغاز, النباتات الكيميائية, high-pressure steam lines.

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الانزلاق على شفة

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.

المزايا:

• Simple installation and alignment

• Lower initial cost than weld neck flanges

• Suitable for applications with limited space

التطبيقات: أنظمة معالجة المياه, HVAC piping, low-pressure industrial lines.

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شفة لحام المقبس

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, أنابيب الضغط العالي.

المزايا:

• Smooth bore flow path

• مناسب لحالات الضغط المرتفع, small-size pipelines

• Good fatigue strength

التطبيقات: الأنظمة الهيدروليكية, chemical process piping, high-pressure gas distribution.

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شفة مترابطة

Threaded flanges have internal threads that match the pipe threads, allowing connection without welding. They are ideal for low-pressure, التطبيقات غير الحرجة.

المزايا:

• لا حاجة للحام

• Suitable for flammable environments where welding is hazardous

• Easy to install and remove

التطبيقات: أنظمة الحماية من الحرائق, خطوط المرافق, compressed air piping.

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شفة اللفة المشتركة

يتم استخدام الشفاه المشتركة مع نهاية كعب, allowing the flange to rotate freely for easy bolt alignment. They are often used in systems requiring frequent disassembly.

المزايا:

• سهولة المحاذاة أثناء التثبيت

• Reusable in different piping assemblies

• Ideal for systems subject to frequent maintenance

التطبيقات: تجهيز الأغذية, مصانع الأدوية, 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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شفة عمياء

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

المزايا:

• Allows access for inspection and cleaning

• Can be installed or removed without disturbing the piping system

• Available in high-pressure ratings

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

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2. Classification by Face Type

وجه مرفوع (الترددات اللاسلكية)

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

التطبيقات: النفط والغاز, المعالجة الكيميائية, أنظمة المياه.

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وجه مسطح (FF)

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

التطبيقات: معالجة المياه, low-pressure applications, non-metallic piping.

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نوع الحلقة المشتركة (آر تي جيه)

Uses a metal ring gasket to achieve a high-integrity seal for high-pressure, تطبيقات درجات الحرارة العالية.

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

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اللسان والأخدود (ت&ز)

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

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

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3. Classification by Pressure Rating

ASME Pressure Classes

• فصل 150

• فصل 300

• فصل 600

• فصل 900

• فصل 1500

• فصل 2500

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

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EN / DIN PN Ratings

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

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JIS Pressure Ratings

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

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4. Classification by Manufacturing Method

الشفاه مزورة

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

التطبيقات: خطوط أنابيب الضغط العالي, offshore structures, محطات توليد الطاقة.

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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.

التطبيقات: أنظمة المياه, low-pressure chemical processing.

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الشفاه لوحة

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

التطبيقات: Low-pressure piping, ventilation systems.

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5. Special Purpose Flanges

الشفاه الفوهة

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

التطبيقات: Flow measurement in oil, غاز, and water pipelines.

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النظارات العمياء الشفاه

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

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

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تقليل الشفاه

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

التطبيقات: Space-constrained piping layouts, retrofit projects.

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Importance of Choosing the Right Flange Type

The correct flange classification ensures safety, التوافق, 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. تشمل المعايير المشتركة:

• ASME B16.5 (الشفاه الأنابيب والتجهيزات ذات الحواف)

• ASME B16.47 (الشفاه الفولاذية ذات القطر الكبير)

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

• JIS B2220 (Japanese Industrial Standard for Flanges)

الشركات المصنعة مثل ساسا مستطيل produce flanges in compliance with these standards to guarantee performance in diverse applications.

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خاتمة

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, نوع الوجه, تصنيف الضغط, 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, أمان, and cost-effectiveness in their piping systems. Partnering with experienced manufacturers like ساسا مستطيل ensures that flanges are produced to precise specifications, ready to perform in even the most demanding environments.