SIST EN 4029:2002

Overview

EN 4029:2001 specifies requirements for tees, bulkhead branch, intended for aerospace pipe couplings with an 8°30' configuration manufactured in titanium alloy. The standard addresses design intent, dimensional data, material selection, surface treatment and marking for components used in high‑pressure aerospace fluid systems.

Key operational limits defined in the standard:

• Nominal pressure: up to 28 000 kPa (28 MPa)
• Temperature range: -55 °C to 135 °C

This document is part of the AECMA/CEN aerospace series and is intended for manufacturers, design engineers and quality teams engaged in aircraft and spacecraft fluid system components.

Key Topics

• Configuration and dimensions: Dimensions and mass are given by reference to figure 1 and table 1. The standard provides size codes (e.g., MJ series) and associated dimensional data; unspecified dimensions may be chosen by the manufacturer provided qualification and acceptance (EN 3275, type II) are met.

• Materials: Titanium alloys are specified by references to the EN 331x series (TI‑P64001 variants). Selection follows the normative references included in the standard.

• Surface treatment and lubrication: Threads and sealing faces require lubrication per EN 2491. Prior to lubricant application, surfaces must be abrasive blasted with non‑metallic grit. Specified lubricant film thickness: 0.005 mm to 0.013 mm.

• Internal finishing: Internal radii shall be R = 0.3 mm to 1.0 mm with a surface roughness of 0.8 µm. Hand deburring is explicitly prohibited.

• Marking and identification: Marking follows EN 2424 (style A) and the designation format is explained in the standard.

• Technical and installation guidance: Technical specification and acceptance conform to EN 3275 (type II). Installation details reference wash ers (EN 3267) and bulkhead interface geometry.

Applications

This standard is applicable to aerospace fluid systems requiring reliable, high‑pressure pipe couplings with bulkhead branch connections. Typical applications include:

• Fluid and hydraulic distribution manifolds in aircraft and spacecraft
• Fuel, hydraulic and pneumatic systems where titanium alloys are specified for weight, corrosion resistance and strength
• Situations demanding controlled surface finish, precise sealing and traceable marking for maintenance and certification

EN 4029:2001 supports procurement, manufacturing and quality assurance by defining consistent characteristics that ensure interchangeability and performance under the listed pressure and temperature limits.

Related Standards

EN 4029 references and is intended to be used with related aerospace standards, including:

• ISO 5855‑3 (MJ threads limits for fittings)
• EN 2424 (marking)
• EN 2491 (dry lubricant coatings)
• EN 3267 (bulkhead washers in titanium)
• EN 3274 / EN 3275 (pipe coupling geometry and technical specification)
• EN 3311 / EN 3312 / EN 3314 / EN 3315 (titanium alloy material specifications)

For designers and manufacturers, cross‑referencing these documents ensures compliance with material, dimensional, surface and installation requirements defined by EN 4029:2001.