Boru sistemlerinde, the flanş kaplama is a critical feature that determines how two flanges seal together with the help of a gasket. Düzgün yüzleşmeden, even the strongest flanges and the best bolts cannot prevent leaks. Two of the most widely recognized standards for flanges are ASME B16.5 Ve 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, their functions, 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

• Basınç değerleri: Sınıf 150 sınıfa 2500

• Common in small- to medium-diameter piping systems

ASME B16.47

• Kapaklar large-diameter steel flanges itibaren NPS'ler 26 NPS'ye 60

• Two series: A Serisi (heavier, for high-pressure applications) Ve B Serisi (çakmak, uygun maliyetli, derived from MSS SP-44)

• Basınç değerleri: Sınıf 75 sınıfa 900

Birlikte, these two standards cover nearly the entire range of industrial flanges used in oil and gas, kimyasal işleme, enerji üretimi, su arıtma, ve deniz mühendisliği.

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What is Flange Facing?

The flanş kaplama 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, sıcaklık, ve sıvı tipi.

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

1. Yükseltilmiş Yüz (RF)

• 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 ile 2500

Uygulamalar: Oil refineries, kimyasal tesisler, water treatment systems

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2. Düz Yüz (FF)

• Entire face of the flange is flat

• Usually used with cast iron and fiberglass piping

• Designed for low-pressure, kritik olmayan uygulamalar

Uygulamalar: Water distribution, pompa bağlantıları, low-pressure pipelines

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3. Halka Tipi Bağlantı (RTJ)

• A machined groove accommodates a metallic ring gasket

• Provides metal-to-metal seal

• Withstands very high pressure and temperature

• Available in Classes 600 ve üzeri

Uygulamalar: Offshore drilling, petrokimya, high-pressure gas systems

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4. Dil ve Oluk (T&G)

• Bir flanşın yükseltilmiş dili vardır, ve diğerinde eşleşen bir oyuk var

• Prevents gasket displacement during installation

• Provides excellent alignment

Uygulamalar: Isı eşanjörleri, kimyasal reaktörler, custom piping assemblies

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5. Erkek ve Kadın (M&F)

• T'ye benzer&G but with flat mating surfaces

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

• Ensures accurate gasket positioning

Uygulamalar: Specialty piping, havacılık, and chemical systems

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Surface Finish Requirements

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

• Stock Finish: En yaygın, concentric or spiral serrated finish (Ra 125–500 µin)

• Smooth Finish: 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. Çalışma Basıncı ve Sıcaklığı

• İçin yüksek basınç, yüksek sıcaklık applications → RTJ is recommended

• İçin alçak basınç, ambient conditions → FF or RF may be sufficient

2. Conta Tipi

• Yumuşak contalar (lastik, PTFE): Require smooth finishes

• Metalik contalar (sarmal yara, 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. Cost and Availability

• 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

Petrol ve Gaz Endüstrisi

• RTJ flanges for offshore rigs, subsea pipelines, ve rafineriler

• RF flanges for midstream and downstream processing

Kimya ve Petrokimya

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

• Corrosion-resistant alloys required for aggressive chemicals

Güç Üretimi

• 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

Denizcilik ve Gemi İnşaatı

• 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 sızıntı önleme. Poorly selected or incorrectly finished facings lead to gasket failure, aksama süresi, and costly repairs. Engineers must evaluate the conta malzemesi, bolt torque, and pressure-temperature rating when specifying flange facings.

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Çözüm

Flange facing is a critical element of ASME B16.5 and B16.47 flanges, ensuring reliable sealing and safe operation in diverse industries. Yükseltilmiş Yüz is the most commonly used, Düz Yüz is preferred for low-pressure systems, Ve Halka Tipi Bağlantı is indispensable for high-pressure, high-temperature applications. Other facings such as Dil & Oluk Ve Male & Female are used in specialized systems requiring precision alignment.

For industries seeking reliable, yüksek kaliteli flanş çözümleri, Sasaflance teklifler ASME B16.5 and B16.47 flanges with precise facings tailored to specific applications. With strict adherence to global standards and advanced manufacturing technology, Sasaflance ensures long-term safety, performans, 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.