SIST EN 2845:2014

Overview

SIST EN 2845:2014 is a European standard developed by the Slovenski inštitut za standardizacijo (SIST) that specifies the properties of acrylonitrile-butadiene rubber (NBR) for aerospace use. This NBR compound is characterized by its resistance to fuels and synthetic oils and features a defined hardness of 50 IRHD (International Rubber Hardness Degrees). The standard ensures that the material consistently meets aerospace sector demands for durability, chemical resistance, and performance across a specific temperature range.

This standard aligns with EN 2845:2013 and is recognized across numerous European countries, promoting harmonized quality and safety in aerospace material selection.

Key Topics

• Material Properties: Details the required fuel and synthetic oil resistance, mechanical strengths (such as tensile strength, elongation at break, and minimum hardness), and chemical stability for NBR compounds.
• Temperature Range: Specifies suitability for continuous operation between −40 °C and +120 °C, and intermittent use up to +150 °C, making NBR suitable for varied aerospace conditions.
• Performance Testing: Outlines the batch testing and qualification processes, including reference to standardized test specimens and laboratory methods according to EN 3207 and ISO 1817.
• Designation System: Provides a method to describe and identify compliant rubber materials for easy reference in procurement and engineering documentation.

Applications

Aerospace Applications

SIST EN 2845:2014 is primarily intended for aerospace applications where resistance to aggressive environments, such as exposure to petroleum-based fuels and synthetic lubricants, is required. Typical uses include:

• Seals and Gaskets: NBR is used for O-rings, gaskets, and other sealing components in aircraft fuel and lubrication systems, where exposure to oils and fuels is constant.
• Flexible Connectors: Used in hoses and diaphragms where flexibility and chemical resistance are vital.
• Vibration Control: NBR’s resilience and longevity make it suitable for vibration damping components in aerospace assemblies.
• Maintenance and Replacement: The standardized properties facilitate easy replacement and maintenance planning in aircraft systems needing reliable oil and fuel resistance.

The defined testing protocols and property thresholds in SIST EN 2845:2014 allow manufacturers, suppliers, and end-users to ensure consistent material performance and safety across the aerospace supply chain.

Related Standards

For comprehensive quality assurance and in-depth specification, SIST EN 2845:2014 references several key standards:

• EN 3207: Specifies technical requirements for rubber compounds used in aerospace, including property testing.
• ISO 1817: Provides test methods for determining the effect of liquids on vulcanized or thermoplastic rubber, critical for verifying chemical resistance.
• ISO 1629: Defines nomenclature for rubber and latices, ensuring consistent material identification across standards.

Standardization through SIST EN 2845:2014 supports interoperability and compliance throughout European and international aerospace industries, streamlining engineering, procurement, and quality management processes. By adhering to these requirements, organizations can enhance safety, reliability, and operational lifetime for aerospace components manufactured with fuel and oil resistant NBR rubber.