SIST EN 4233:2004

Aerospace series - Pipe coupling 8°30' in titanium alloy - Unions, welded end, threaded

This standard specifies the characteristics of unions, welded end, threaded for pipe couplings 8°30', in titanium alloy, for aerospace applications.
Nominal pressure: up to 28 000 kPa
Temperature range: - 55 °C to 135 °C

Luft- und Raumfahrt - Rohrverschraubung 8°30' aus Titanlegierung - Gerade Verschraubungen mit Anschweißende

Diese Norm legt die Eigenschaften von geraden Verschraubungen mit Anschweißende für Rohrverschraubungen 8°30' aus Titanlegierung, zur Verwendung in der Luft- und Raumfahrt fest.
Nenndruck: bis 28 000 kPa
Temperaturbereich: - 55 °C bis 135 °C

Série aérospatiale - Systeme de raccordement 8°30' en alliage de titane - Raccords droits, a souder, filetés

La présente norme spécifie les caractéristiques des raccords droits, à souder, filetés, pour les systèmes de raccorde-ment 8°30', en alliage de titane, pour applications aérospatiales.
Pression nominale: jusqu'à 28 000 kPa
Plage de températures: - 55 °C à 135 °C

Aerospace series - Pipe coupling 8°30' in titanium alloy - Unions, welded end, threaded

General Information

• Status: Published
• Publication Date: 30-Apr-2004
• ICS: 49.080 - Aerospace fluid systems and components
• Technical Committee: I08 - Imaginarni 08
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-May-2004
• Due Date: 01-May-2004
• Completion Date: 01-May-2004
• Ref Project: EN 4233:2001 - Aerospace series - Pipe coupling 8°30' in titanium alloy - Unions, welded end, threaded

Relations

• Refers: SIST EN 3275:2019 - Aerospace series - Pipe coupling 8°30' up to 28 000 kPa Dynamic beam seal - Metric series - Technical specification
• Effective Date: 28-Jan-2026
• Refers: SIST EN 3274:2011 - Aerospace series - Pipe coupling 8°30' - Thread end - Geometric configuration
• Effective Date: 28-Jan-2026
• Refers: SIST EN 3311:2024 - Aerospace series - Titanium alloy TI-P64001 (Ti-6Al-4V) - Annealed - Bars for machining - D ≤ 300 mm - 900 MPa ≤ Rm ≤ 1 160 MPa
• Effective Date: 28-Jan-2026
• Refers: SIST EN 2656:2002 - Aerospace series - Pipe coupling - Coupling end, welded - Geometric configuration
• Effective Date: 28-Jan-2026
• Refers: oSIST prEN 415-2:2022 - Safety of packaging machines - Part 2: Packaging machines for pre-formed rigid containers
• Effective Date: 28-Jan-2026
• Refers: SIST EN 2491:2011 - Aerospace series - Molybdenum disulphide dry lubricants - Coating methods
• Effective Date: 28-Jan-2026
• Refers: SIST EN 2424:2008 - Aerospace series - Marking of aerospace products
• Effective Date: 28-Jan-2026
• Referred By: SIST EN 3084:2002 - Aerospace series - Pipe coupling 8°30' in titanium alloy - Unions, welded end threaded for repair
• Effective Date: 28-Jan-2026

Overview

SIST EN 4233:2004 is a European standard developed by CEN for the aerospace industry, titled “Aerospace series - Pipe coupling 8°30' in titanium alloy - Unions, welded end, threaded.” This standard establishes the characteristics and specifications for titanium alloy threaded union fittings with a welded end, specifically designed for use in aerospace pipe coupling systems with an 8°30' interface. Covering applications that require high performance and reliability, SIST EN 4233:2004 supports nominal pressures up to 28,000 kPa and ensures operational safety within a temperature range of -55°C to 135°C.

Key Topics

• Material Specification
  The standard specifies the use of titanium alloys for union fittings, optimizing strength-to-weight ratio and corrosion resistance - critical factors in aerospace fluid systems.

• Design and Dimensions
  SIST EN 4233:2004 defines dimensional requirements and tolerances for welded end, threaded unions, referencing relevant configurations and codes for compatibility with aerospace pipe coupling systems.

• Pressure and Temperature Ratings
  Suitable for high-pressure environments up to 28,000 kPa, the fittings maintain integrity and performance in extreme temperature conditions (-55°C to 135°C).

• Surface Treatment and Lubrication
  Details on required surface treatment and lubrication methods are included, referencing standards such as EN 2491 for lubricant types and application, ensuring optimal function and extended lifespan of threaded connections.

• Marking and Identification
  Requirements for clear and accurate product marking are aligned with EN 2424, supporting traceability and compliance in aerospace manufacturing and maintenance.

Applications

EN 4233 unions are designed specifically for aerospace fluid systems where reliability and compliance with rigorous standards are paramount. Practical applications include:

• Hydraulic systems: Used in aircraft and spacecraft hydraulic lines due to their ability to withstand high pressures.
• Fuel and fluid conveyance: Suitable for fuel, lubrication, and cooling fluid lines that demand high performance under variable thermal and pressure conditions.
• Maintenance and retrofitting: The standardized dimensions and threads facilitate quick replacement and maintenance of pipe couplings across fleets, supporting industry best practices for safety and efficiency.
• OEM and supply chain integration: Ensures compatibility among industry suppliers, manufacturers, and maintenance providers working within the aerospace sector.

Related Standards

SIST EN 4233:2004 references, aligns with, or is complemented by several key aerospace standards, including:

• ISO 5855-3: Limit dimensions for MJ threads used in aerospace fluid systems.
• EN 2424: Marking of aerospace products for identification and traceability.
• EN 2491: Specifications for molybdenum disulphide dry lubricants and coating methods.
• EN 2656: Geometric configuration requirements for welded coupling ends.
• EN 3274: Geometric configurations for thread ends in pipe couplings.
• EN 3275: Technical specifications for dynamic beam seal metric series pipe couplings.
• EN 3311 / EN 3314: Material requirements for titanium alloy bars used in aerospace applications.

By ensuring compliance with SIST EN 4233:2004 and these related standards, aerospace manufacturers and maintenance providers can achieve high reliability, safety, and standardization in fluid systems components across a wide range of aircraft and spacecraft platforms.

Keywords: EN 4233, pipe coupling, titanium alloy, aerospace union, welded end, threaded, CEN standards, aerospace fluid system, high-pressure fittings, aerospace coupling standard.

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Aerospace series - Pipe coupling 8°30' in titanium alloy - Unions, welded end, threadedLuft- und Raumfahrt - Rohrverschraubung 8°30' aus Titanlegierung - Gerade Verschraubungen mit AnschweißendeSérie aérospatiale - Systeme de raccordement 8°30' en alliage de titane - Raccords droits, a souder, filetésAerospace series - Pipe coupling 8°30' in titanium alloy - Unions, welded end, threaded49.080Aerospace fluid systems and componentsICS:Ta slovenski standard je istoveten z:EN 4233:2001SIST EN 4233:2004en01-maj-2004SIST EN 4233:2004SLOVENSKI
STANDARD
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 4233October 2001ICS 49.080English versionAerospace series - Pipe coupling 8°30' in titanium alloy -Unions, welded, threadedSérie aérospatiale - Système de raccordement 8°30' enalliage de titane - Raccords droits, soudés, filetésLuft- und Raumfahrt - Rohrverschraubung 8°30' ausTitanlegierung - Gerade Verschraubungen zumAnschweißenThis European Standard was approved by CEN on 1 January 2001.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2001 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 4233:2001 ESIST EN 4233:2004
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