Dalam sistem perpipaan, itu menghadap flensa is a critical feature that determines how two flanges seal together with the help of a gasket. Tanpa menghadap dengan benar, even the strongest flanges and the best bolts cannot prevent leaks. Two of the most widely recognized standards for flanges are ASME B16.5 Dan ASME B16.47. While both cover different flange size ranges, their facing types share common design principles and applications.

This article provides a detailed guide on flange facing for B16.5 and B16.47 flanges, explaining the types of facings, fungsi mereka, and the key considerations engineers must evaluate when selecting the right flange connection for industrial projects.

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Overview of B16.5 and B16.47 Flanges

ASME B16.5

• Covers flanges and flanged fittings from NPS ½ to NPS 24

• Peringkat tekanan: Kelas 150 ke Kelas 2500

• Common in small- to medium-diameter piping systems

ASME B16.47

• Meliputi flensa baja berdiameter besar dari NPC 26 ke NPC 60

• Two series: Seri A (heavier, for high-pressure applications) Dan Seri B (lebih ringan, hemat biaya, derived from MSS SP-44)

• Peringkat tekanan: Kelas 75 ke Kelas 900

Together, these two standards cover nearly the entire range of industrial flanges used in oil and gas, pemrosesan kimia, pembangkit listrik, pengolahan air, dan teknik kelautan.

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What is Flange Facing?

Itu menghadap flensa is the finish applied to the surface of the flange that comes into contact with the gasket. Its purpose is to ensure tight sealing, proper load distribution, and gasket retention. Different facing types are specified depending on the application’s pressure, suhu, dan tipe fluida.

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Common Flange Facing Types for B16.5 and B16.47

1. Wajah Terangkat (Federasi Rusia)

• Most widely used facing type

• A small area around the bore is raised above the bolt circle

• Standard roughness ensures gasket grip

• Used in Classes 150 ke 2500

Aplikasi: Kilang minyak, tanaman kimia, sistem pengolahan air

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2. Wajah Datar (FF)

• Entire face of the flange is flat

• Usually used with cast iron and fiberglass piping

• Designed for low-pressure, aplikasi non-kritis

Aplikasi: Water distribution, koneksi pompa, pipa bertekanan rendah

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3. Sambungan Tipe Cincin (RTJ)

• A machined groove accommodates a metallic ring gasket

• Provides segel logam-ke-logam

• Withstands very high pressure and temperature

• Available in Classes 600 dan di atasnya

Aplikasi: Pengeboran lepas pantai, petrokimia, high-pressure gas systems

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4. Lidah dan Alur (T&G)

• Salah satu flensa memiliki lidah yang terangkat, dan yang lainnya memiliki alur yang serasi

• Prevents gasket displacement during installation

• Provides excellent alignment

Aplikasi: Penukar panas, reaktor kimia, custom piping assemblies

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5. Pria dan Wanita (M&F)

• Mirip dengan T&G but with flat mating surfaces

• Male flange has a raised portion; female flange has a matching recess

• Ensures accurate gasket positioning

Aplikasi: Specialty piping, luar angkasa, and chemical systems

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Persyaratan Permukaan Akhir

ASME standards specify the surface roughness of flange facings to ensure proper gasket interaction:

• Stok Selesai: Paling umum, concentric or spiral serrated finish (Ra 125–500 µin)

• Selesai Halus: For soft gaskets, provides improved contact area (Ra 63–125 µin)

• Cold Water Finish: Extremely smooth finish for special soft gaskets (Ra ≤ 63 µin)

Key Point: The correct surface finish prevents leakage and extends gasket life.

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Key Considerations for Selecting Flange Facing

1. Tekanan dan Temperatur Operasi

• Untuk tekanan tinggi, suhu tinggi applications → RTJ is recommended

• Untuk low-pressure, ambient conditions → FF or RF may be sufficient

2. Jenis Gasket

• Gasket lembut (karet, PTFE): Require smooth finishes

• Gasket logam (luka spiral, RTJ): Require serrated or grooved facings

3. Piping Material Compatibility

• Cast iron and non-metallic pipes → Use Flat Face

• Steel and alloy pipelines → Use Raised Face or RTJ

4. Maintenance and Accessibility

• RF and FF flanges are easier to assemble and maintain

• RTJ flanges require precise machining and ring gasket handling

5. Biaya dan Ketersediaan

• RF and FF are cost-effective and widely available

• RTJ, T&G, and M&F are more expensive but necessary for critical service

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Applications of B16.5 and B16.47 Flange Facing

Industri Minyak dan Gas

• RTJ flanges for offshore rigs, jaringan pipa bawah laut, dan kilang

• RF flanges for midstream and downstream processing

Kimia dan Petrokimia

• RF and T&G flanges in reactors and distillation units

• Corrosion-resistant alloys required for aggressive chemicals

Pembangkit Listrik

• RTJ flanges for high-pressure steam lines

• RF flanges for cooling water systems

Water Treatment and Distribution

• FF flanges for low-pressure water pipelines

• RF flanges for desalination and wastewater plants

Kelautan dan Pembuatan Kapal

• Stainless steel RF flanges for seawater cooling

• RTJ flanges for marine exhaust and fuel systems

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Flange Facing and Leak Prevention

The correct flange facing directly influences pencegahan kebocoran. Poorly selected or incorrectly finished facings lead to gasket failure, waktu henti, and costly repairs. Engineers must evaluate the bahan paking, torsi baut, and pressure-temperature rating when specifying flange facings.

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Kesimpulan

Flange facing is a critical element of ASME B16.5 and B16.47 flanges, ensuring reliable sealing and safe operation in diverse industries. Wajah Terangkat is the most commonly used, Wajah Datar is preferred for low-pressure systems, Dan Sambungan Tipe Cincin is indispensable for high-pressure, aplikasi suhu tinggi. Other facings such as Lidah & Alur Dan Male & Female are used in specialized systems requiring precision alignment.

For industries seeking reliable, high-quality flange solutions, sasa lonjong penawaran ASME B16.5 and B16.47 flanges with precise facings tailored to specific applications. With strict adherence to global standards and advanced manufacturing technology, sasa lonjong ensures long-term safety, pertunjukan, and efficiency in piping systems worldwide.

By carefully considering flange facing types, engineers and buyers can optimize system integrity, reduce leakage risks, and extend the service life of critical piping components.