VW TL 52694 Corrugated Pipe - Material Requirements and Contents

The “VW TL 52694 Corrugated Pipe - Material Requirements and Content” standard, developed by the Volkswagen automotive company, describes the material requirements for non-dividing, medium-carrying, corrugated pipes used in systems such as positive sump ventilation systems, high-temperature positive sump ventilation systems, transmission ventilation, fuel lines in or above the fuel tank, and washer fluid hoses.

The general requirements in this standard are determined as follows:

• Initial supply and modification approvals must comply with VW 01155 standard.
• Material suitability must be in accordance with the VW 91101 standard.
• Limit deviations must conform to the DIN 73378 standard.
• Prefabricated lines containing approximately 10 m of corrugated pipe are required for complete testing.
• Forming operations must be performed using the procedure planned for production.
• Especially in tests related to environmental resistance, pipes with a nominal diameter of ND 19 are preferred for basic tests.

The appearance requirements are determined as follows:

• Corrugated pipes must be free from manufacturing defects such as bubbles, voids, scratches, cracks, irregularities, and foreign matter.
• Pipes must be free of weak points arising from process steps necessary for manufacturing, such as the installation of support sleeves and barbed fittings.
• The dividing line should not protrude more than 0,15 mm in either the longitudinal or transverse directions.
• Embossed sections (e.g., manufacturer markings) are unacceptable in the sealing area.

Production requirements were defined as follows:

• Corrugated pipes are typically produced by extrusion and then shaped in a corrugating machine.
• The endless tubes are then cut and shaped as desired through thermal forming.
• The supplier must select the groove geometry to meet the Development department's requirements in terms of bending capability and functionality.

Prior to testing, samples required for individual tests must be conditioned for at least 48 hours in a standard atmosphere according to VW 50554 23/50-2.

When evaluating measurement results, the requirements apply to all points of the pipe or laid pipe. The necessary numerical values ​​apply separately to each measurement.

Material requirements are detailed in the VW TL 52694 standard as follows:

• Positive crankcase ventilation system
• Positive crankcase ventilation system
• Positive crankcase ventilation system for high-temperature applications.
• fuel line to or onto the fuel tank (fuel tank)
• Windshield washer hose (windshield washer fluid)
• Transmission ventilation

The VW TL 52694 standard defines material and performance requirements for non-corrugated, media-carrying corrugated tubing used in automotive applications. These tubings are typically manufactured from thermoplastics (such as polyamides or bio-based variants) and are designed to transport media under harsh conditions in vehicles.

This standard primarily covers corrugated pipes in systems such as:

• Positive crankcase ventilation (PCV) systems
• High temperature positive sump ventilation systems
• Other liquid or vapor carrying lines in engine compartments where flexibility, temperature resistance, chemical resistance and durability are required.

These pipes must withstand exposure to oils, fuels, combustion gases, heat, pressure changes, and environmental stresses without leaking, cracking, or premature deterioration.

The TL 52694 standard specifies a set of tests and limits for the following:

• Dimensional requirements: For example, nominal widths (NW 19 is generally preferred for many basic tests).
• Mechanical properties: Elasticity, burst pressure, impact resistance, bending/vibration fatigue.
• Chemical resistance: Resistance to substances such as motor oils, fuels, combustion vapors, and other automotive fluids (tests typically involve immersion or exposure followed by property checks).
• Thermal aging and heat resistance: Prolonged exposure to high temperatures.
• Soluble substances: Limits on leaching components (e.g., in fuel or oil contact applications).
• Low-temperature behavior: Cold impact and flexibility.
• Other durability tests include: ozone resistance, weather resistance, and hydrolysis stability.

This standard emphasizes the importance of testing on actual corrugated pipe samples, which typically include specific limits for properties such as soluble components or mechanical adhesion after exposure.

Suppliers of plastic pipes and components must demonstrate compliance with the VW TL 52694 standard to obtain approval for mass production. Independent testing laboratories carry out these qualification tests.

In short, the VW TL 52694 standard is designed for the following purposes:

• To define material, performance, and quality requirements for parts sourced from external suppliers.
• Ensuring that components meet engineering, safety, and durability criteria before being used in vehicles.
• To provide suppliers with a standard reference for the design and manufacture of parts that will work reliably in vehicles.

The VW TL 52694 standard relates to corrugated tubing used inside vehicles. This tubing typically acts as flexible ductwork in systems such as:

• Positive crankcase ventilation (PCV) systems
• High-temperature ventilation systems
• Ventilation lines
• Fuel and steam lines located in or near fuel tanks
• Windshield washer hoses

This standard defines how these corrugated tubes should be manufactured and tested to withstand the mechanical, thermal, and chemical stresses common in automotive environments.

Although corrugated pipes may seem simple, they play vital roles in vehicle performance and safety:

• They must be able to flex without cracking under vibration and heat.
• They must be resistant to oil, fuel vapors, and other chemicals.
• They need to maintain their structural integrity for years and over thousands of kilometers.

Without precise standards like VW TL 52694, inconsistent quality can lead to premature failures, emission problems, or safety issues. Suppliers producing corrugated tubing must design and test their products according to the requirements of this standard. Engineering/testing laboratories and automotive certification bodies offer testing services to verify compliance. These standards are also referenced internally by manufacturers and service providers, particularly when evaluating replacement parts or aftermarket components for critical systems.

For many years, our organization, with its competent and experienced team, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services compliant with the VW TL 52694 standard.