Detaillierte Klassifizierung häufig verwendeter…

Flansche sind wesentliche Komponenten in Rohrleitungssystemen, dienen als mechanische Verbindungen zum Verbinden von Rohren, Ventile, Pumps, und andere Ausrüstung. Sie bieten eine sichere, eine auslaufsichere Verbindung und ermöglicht gleichzeitig eine einfache Demontage, Inspektion, und Wartung. Flanges are used in industries such as oil and gas, chemische Verarbeitung, Wasseraufbereitung, Stromerzeugung, Schiffbau, and HVAC systems. To ensure proper application and performance, flanges are classified into several types based on their structure, Verbindungsmethode, Druckstufe, and application environment. This article provides a detailed classification of commonly used flanges, offering insight into their features, Vorteile, and typical uses.

1. Classification by Connection Method

Vorschweißflansch

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.

Vorteile:

Excellent strength and fatigue resistance
Smooth bore transition reduces turbulence
Ideal for repeated bending and temperature cycles

Anwendungen: Öl- und Gaspipelines, Chemieanlagen, high-pressure steam lines.

Aufsteckflansch

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.

Vorteile:

Simple installation and alignment
Geringere Anschaffungskosten als Vorschweißflansche
Suitable for applications with limited space

Anwendungen: Wasseraufbereitungssysteme, HVAC piping, low-pressure industrial lines.

Muffenschweißflansch

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, Hochdruckleitungen.

Vorteile:

Smooth bore flow path
Geeignet für Hochdruck, small-size pipelines
Good fatigue strength

Anwendungen: Hydrauliksysteme, chemical process piping, high-pressure gas distribution.

Gewindeflansch

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

Vorteile:

Kein Schweißen erforderlich
Suitable for flammable environments where welding is hazardous
Einfach zu installieren und zu entfernen

Anwendungen: Brandschutzsysteme, Versorgungsleitungen, compressed air piping.

Überlappungsflansch

Überlappungsflansche werden mit Stummelende verwendet, allowing the flange to rotate freely for easy bolt alignment. They are often used in systems requiring frequent disassembly.

Vorteile:

Einfache Ausrichtung während der Installation
Reusable in different piping assemblies
Ideal for systems subject to frequent maintenance

Anwendungen: Lebensmittelverarbeitung, pharmazeutische Anlagen, corrosive environments where flanges can be made from a less expensive material and the stub end from a corrosion-resistant alloy.

Blindflansch

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

Vorteile:

Allows access for inspection and cleaning
Can be installed or removed without disturbing the piping system
Available in high-pressure ratings

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

2. Classification by Face Type

Erhöhtes Gesicht (RF)

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

Anwendungen: Öl und Gas, chemische Verarbeitung, Wassersysteme.

Flaches Gesicht (FF)

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

Anwendungen: Wasseraufbereitung, Niederdruckanwendungen, non-metallic piping.

Ringgelenk (RTJ)

Uses a metal ring gasket to achieve a high-integrity seal for high-pressure, Hochtemperaturanwendungen.

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

Nut und Feder (T&G)

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

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

3. Classification by Pressure Rating

ASME Pressure Classes

Klasse 150
Klasse 300
Klasse 600
Klasse 900
Klasse 1500
Klasse 2500

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

EN / DIN PN Ratings

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

JIS-Druckwerte

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

4. Classification by Manufacturing Method

Geschmiedete Flansche

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

Anwendungen: Hochdruckleitungen, offshore structures, Kraftwerke.

Cast Flanges

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

Anwendungen: Wassersysteme, low-pressure chemical processing.

Plattenflansche

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

Anwendungen: Low-pressure piping, ventilation systems.

5. Special Purpose Flanges

Öffnungsflansche

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

Anwendungen: Flow measurement in oil, Gas, and water pipelines.

Brillen-Blindflansche

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

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

Reduzierflansche

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

Anwendungen: Space-constrained piping layouts, retrofit projects.

Importance of Choosing the Right Flange Type

The correct flange classification ensures safety, Kompatibilität, 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.

Standards Governing Flanges

Flanges must conform to international standards to ensure quality and interchangeability. Zu den gängigen Standards gehören::

ASME B16.5 (Rohrflansche und Flanschverbindungen)
ASME B16.47 (Stahlflansche mit großem Durchmesser)
EN 1092-1 (European Standard for Steel Flanges)
JIS B2220 (Japanese Industrial Standard for Flanges)

Hersteller mögen sasa länglich produce flanges in compliance with these standards to guarantee performance in diverse applications.

Abschluss

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, Gesichtstyp, Druckstufe, 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, Sicherheit, and cost-effectiveness in their piping systems. Partnering with experienced manufacturers like sasa länglich ensures that flanges are produced to precise specifications, ready to perform in even the most demanding environments.