Flensa merupakan komponen penting dalam sistem perpipaan, berfungsi sebagai konektor mekanis untuk menyambung pipa, katup, pompa, dan peralatan lainnya. Mereka menyediakan keamanan, sambungan anti bocor sekaligus memudahkan pembongkaran, inspeksi, dan pemeliharaan. Flanges are used in industries such as oil and gas, pemrosesan kimia, pengolahan air, pembangkit listrik, pembuatan kapal, dan sistem HVAC. To ensure proper application and performance, flanges are classified into several types based on their structure, metode koneksi, peringkat tekanan, dan lingkungan aplikasi. This article provides a detailed classification of commonly used flanges, offering insight into their features, keuntungan, and typical uses.

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1. Classification by Connection Method

Flensa Leher Las

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.

Keuntungan:

• Excellent strength and fatigue resistance

• Smooth bore transition reduces turbulence

• Ideal for repeated bending and temperature cycles

Aplikasi: Jaringan pipa minyak dan gas, tanaman kimia, saluran uap bertekanan tinggi.

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Flensa Selip

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.

Keuntungan:

• Simple installation and alignment

• Biaya awal lebih rendah dibandingkan flensa leher las

• Suitable for applications with limited space

Aplikasi: Sistem pengolahan air, HVAC piping, low-pressure industrial lines.

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Flensa Las Soket

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, pipa bertekanan tinggi.

Keuntungan:

• Smooth bore flow path

• Cocok untuk tekanan tinggi, small-size pipelines

• Good fatigue strength

Aplikasi: Sistem hidrolik, chemical process piping, high-pressure gas distribution.

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Flensa Berulir

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

Keuntungan:

• Tidak diperlukan pengelasan

• Suitable for flammable environments where welding is hazardous

• Easy to install and remove

Aplikasi: Sistem proteksi kebakaran, jalur utilitas, compressed air piping.

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Flensa Sambungan Putaran

Flensa sambungan pangkuan digunakan dengan ujung rintisan, allowing the flange to rotate freely for easy bolt alignment. They are often used in systems requiring frequent disassembly.

Keuntungan:

• Penyelarasan yang mudah selama instalasi

• Reusable in different piping assemblies

• Ideal for systems subject to frequent maintenance

Aplikasi: Pengolahan makanan, tanaman farmasi, 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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Flensa Buta

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

Keuntungan:

• Allows access for inspection and cleaning

• Can be installed or removed without disturbing the piping system

• Available in high-pressure ratings

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

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2. Classification by Face Type

Wajah Terangkat (Federasi Rusia)

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

Aplikasi: Minyak dan gas, pemrosesan kimia, sistem air.

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Wajah Datar (FF)

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

Aplikasi: Pengolahan air, aplikasi tekanan rendah, non-metallic piping.

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Sambungan Tipe Cincin (RTJ)

Uses a metal ring gasket to achieve a high-integrity seal for high-pressure, aplikasi suhu tinggi.

Aplikasi: Refinery equipment, saluran uap bertekanan tinggi, offshore oil platforms.

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Lidah dan Alur (T&G)

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

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

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3. Classification by Pressure Rating

ASME Pressure Classes

• Kelas 150

• Kelas 300

• Kelas 600

• Kelas 900

• Kelas 1500

• Kelas 2500

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

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EN / DIN PN Ratings

hal 6, hal 10, hal 16, hal 25, hal 40, hal 63, hal 100, hal 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

Flensa Tempa

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

Aplikasi: High-pressure pipelines, offshore structures, pembangkit listrik.

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Flensa Cor

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

Aplikasi: Sistem air, low-pressure chemical processing.

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Flensa Pelat

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

Aplikasi: Low-pressure piping, ventilation systems.

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5. Special Purpose Flanges

Flensa Lubang

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

Aplikasi: Flow measurement in oil, gas, and water pipelines.

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Flensa Buta Tontonan

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

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

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Mengurangi Flensa

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

Aplikasi: Space-constrained piping layouts, proyek retrofit.

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Importance of Choosing the Right Flange Type

The correct flange classification ensures safety, kesesuaian, and performance in the intended application. Mismatched flange types can lead to leaks, kehilangan tekanan, 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. Standar umum meliputi:

• ASME B16.5 (Flensa Pipa dan Perlengkapan Berflensa)

• ASME B16.47 (Flensa Baja Diameter Besar)

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

• JIS B2220 (Japanese Industrial Standard for Flanges)

Produsen seperti sasa lonjong produce flanges in compliance with these standards to guarantee performance in diverse applications.

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Kesimpulan

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, tipe wajah, peringkat tekanan, 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, keamanan, and cost-effectiveness in their piping systems. Partnering with experienced manufacturers like sasa lonjong ensures that flanges are produced to precise specifications, ready to perform in even the most demanding environments.