EN 3746:2007
(Main)Aerospace series - O-rings, in fluorosilicone rubber (FVMQ) - Hardness 80 IRHD
Aerospace series - O-rings, in fluorosilicone rubber (FVMQ) - Hardness 80 IRHD
This standard specifies the characteristics of O-rings in fluorosilicone rubber FVMQ, hardness 80 IRHD, for aerospace applications.
They are intended to be used in air, mineral/synthetic oil and fuel systems.
Operating conditions – Temperature:
a) Continuous operation: 55 °C to 150 °C;
b) Intermittent service: 55 °C to 200 °C.
Limitation:
not to be used with phosphoric ester type hydraulic fluids (permanent or temporary immersion).
Luft und Raumfahrt - O-Ringe aus FluorsilikonElastomer (FVMQ) - Härte 80 IRHD
Diese Norm legt die Eigenschaften von O-Ringen aus Fluorsilikon-Elastomer (FVMQ), Härte 80 IRHD, für Anwendungen in der Luft- und Raumfahrt fest.
Diese O-Ringe sind für die Verwendung in Luft-, Öl- (Mineralöl- und synthetisches Öl) und Kraftstoffanlagen bestimmt.
Nutzungsbedingungen - Temperaturbereich:
a) Langzeitverwendung: - 55 °C bis + 150 °C;
b) Kurzzeitverwendung: - 55 °C bis + 200 °C.
Einschränkung:
Sie dürfen nicht mit Hydraulikflüssigkeiten auf Phosphoresterbasis verwendet werden (ständiges oder zeitwei¬ses Eintauchen).
Aeronavtika - O-obročki iz fluorosilikonske gume (FVMQ) - Trdota 80 IRHD
General Information
Relations
Overview
EN 3746:2007 is a European standard developed by CEN that defines the specifications for aerospace-grade O-rings made of fluorosilicone rubber (FVMQ) with a hardness of 80 IRHD. These O-rings are specifically designed for aerospace applications where reliable sealing is critical. The standard outlines the physical, chemical, and dimensional characteristics that ensure the performance and safety of these sealing components in aircraft fuel, oil, and air systems.
Key highlights of the standard include specified temperature ranges for continuous and intermittent operation, material composition, dimensional tolerances, and restrictions on usage with certain hydraulic fluids. EN 3746:2007 replaces the previous 2003 edition and harmonizes national standards across European member states.
Key Topics
Material Composition:
The O-rings are made from fluorosilicone rubber (FVMQ), chosen for its superior chemical resistance and thermal stability. The hardness is fixed at 80 IRHD to ensure consistent mechanical performance.Dimensions and Tolerances:
Detailed tables provide codes, nominal sizes, tolerances, and mass for various O-ring diameters and cross-sectional sizes. These specifications conform to ISO 3601-1 to guarantee interchangeability and compatibility.Operating Temperature Ranges:
- Continuous operation: −55 °C to 150 °C
- Intermittent service: −55 °C to 200 °C
These ranges accommodate the demanding thermal environments encountered in aerospace systems.
Application Limitations:
EN 3746 explicitly states that these fluorosilicone O-rings must not be used with phosphoric ester type hydraulic fluids under any immersion conditions, due to incompatibility risks.Storage and Handling:
Compliance with EN 2751 is required for storage, handling, and packaging to maintain material integrity and prevent contamination.Marking and Designation:
The standard includes guidelines for product marking and packaging according to EN 3747, ensuring traceability and conformity with aerospace supply chain requirements.
Applications
EN 3746:2007 fluorosilicone O-rings are primarily used in aerospace systems where resistance to air, mineral oils, synthetic oils, and fuels is needed, including:
Fuel system sealing:
Ensuring leak-proof connections in fuel lines, pumps, and valves exposed to harsh chemical environments and thermal fluctuations.Oil system interfaces:
Sealing hydraulic and lubrication systems within aircraft engines and auxiliary power units.Air system sealing:
In air distribution and control systems where reliable sealing maintains pressure and prevents contamination.
The material's resistance to a broad temperature range and fluids common in aerospace applications makes these O-rings suitable for high-performance sealing solutions where safety and durability are paramount.
Related Standards
ISO 3601-1:
Defines inside diameters, cross sections, tolerances, and size identification codes for O-rings, ensuring dimensional standardization.EN 2751:
Specifies storage, cleaning, and maintenance requirements for aerospace rubber products to preserve performance.EN 3747:
Details technical specifications and packaging for fluorosilicone O-rings, complementing EN 3746 by providing quality and compliance protocols.EN 3827:
Covers the material characteristics of fluorosilicone rubber (FVMQ) with hardness 80 IRHD, the specific rubber compound used in EN 3746 O-rings.
Summary
EN 3746:2007 sets stringent requirements for fluorosilicone rubber O-rings used in aerospace fuel, oil, and air systems, focusing on material quality, dimensional accuracy, and operational conditions. This European standard ensures high safety, reliability, and performance in critical sealing applications subjected to extreme temperatures and aggressive fluids. Utilization of O-rings compliant with EN 3746 contributes to standardization and interchangeability across aerospace suppliers, aiding in efficient maintenance and manufacturing processes.
Keywords: EN 3746:2007, aerospace O-rings, fluorosilicone rubber, FVMQ, hardness 80 IRHD, aerospace sealing solutions, O-ring dimensions, aircraft fuel system seals, temperature resistance O-rings, aerospace rubber standards, CEN aerospace standards.
Frequently Asked Questions
EN 3746:2007 is a standard published by the European Committee for Standardization (CEN). Its full title is "Aerospace series - O-rings, in fluorosilicone rubber (FVMQ) - Hardness 80 IRHD". This standard covers: This standard specifies the characteristics of O-rings in fluorosilicone rubber FVMQ, hardness 80 IRHD, for aerospace applications. They are intended to be used in air, mineral/synthetic oil and fuel systems. Operating conditions – Temperature: a) Continuous operation: 55 °C to 150 °C; b) Intermittent service: 55 °C to 200 °C. Limitation: not to be used with phosphoric ester type hydraulic fluids (permanent or temporary immersion).
This standard specifies the characteristics of O-rings in fluorosilicone rubber FVMQ, hardness 80 IRHD, for aerospace applications. They are intended to be used in air, mineral/synthetic oil and fuel systems. Operating conditions – Temperature: a) Continuous operation: 55 °C to 150 °C; b) Intermittent service: 55 °C to 200 °C. Limitation: not to be used with phosphoric ester type hydraulic fluids (permanent or temporary immersion).
EN 3746:2007 is classified under the following ICS (International Classification for Standards) categories: 49.025.40 - Rubber and plastics. The ICS classification helps identify the subject area and facilitates finding related standards.
EN 3746:2007 has the following relationships with other standards: It is inter standard links to EN 3746:2003. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
You can purchase EN 3746:2007 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of CEN standards.
Standards Content (Sample)
SLOVENSKI STANDARD
01-marec-2009
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SIST EN 3746:2004
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Aerospace series - O-rings, in fluorosilicone rubber (FVMQ) - Hardness 80 IRHD
Luft und Raumfahrt - O-Ringe aus FluorsilikonElastomer (FVMQ) - Härte 80 IRHD
Ta slovenski standard je istoveten z: EN 3746:2007
ICS:
49.025.40 Guma in polimerni materiali Rubber and plastics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN 3746
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2007
ICS 49.025.40 Supersedes EN 3746:2003
English Version
Aerospace series - O-rings, in fluorosilicone rubber (FVMQ) -
Hardness 80 IRHD
This European Standard was approved by CEN on 11 September 2003.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN 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 translation
under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 3746:2007: E
worldwide for CEN national Members.
Contents Page
Foreword.3
1 Scope .4
2 Normative references .4
3 Required characteristics.4
4 Storage.10
5 Designation .10
6 Marking/Packaging .10
7 Technical specification .10
Foreword
This document (EN 3746:2007) has been prepared by the Aerospace and Defence Industries Association of
Europe - Standardization (ASD-STAN).
After enquiries and votes carried out in accordance with the rules of this Association, this Standard has
received the approval of the National Associations and the Official Services of the member countries of ASD,
prior to its presentation to CEN.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by December 2007, and conflicting national standards shall be withdrawn
at the latest by December 2007.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 3746:2003.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
1 Scope
This standard specifies the characteristics of O-rings in fluorosilicone rubber FVMQ, hardness 80 IRHD, for
aerospace applications.
They are intended to be used in air, mineral/synthetic oil and fuel systems.
Operating conditions – Temperature:
a) Continuous operation: − 55 °C to 150 °C;
b) Intermittent service: − 55 °C to 200 °C.
Limitation:
not to be used with phosphoric ester type hydraulic fluids (permanent or temporary immersion).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 3601-1, Fluid power systems — O-rings — Part 1: Inside diameters, cross-sections, tolerances and size
identification code.
EN 2751, Aerospace series — Storage conditions for rubber products — Requirements for storage, cleaning
1)
and maintenance.
EN 3747, Aerospace series — O-rings, in fluorosilicone rubber (FVMQ) — Technical specification.
2)
EN 3827, Aerospace series — Fluorosilicone rubber (FVMQ) — Hardness 80 IRHD.
3 Required characteristics
3.1 Configuration – Dimensions – Tolerances – Masses
See Figures 1 to 5 and Tables 1 to 5.
Dimensions and tolerances are in millimetres.
3.2 Material
EN 3827
1) In preparation at the date of publication of this standard.
2) Published as ASD Prestandard at the date of publication of this standard.
Figure 1
Table 1
a
Section diameter d ==== 1,8 ± 0,08
Code A
b b b
d Mass d Mass d Mass
1 1 1
Code nom. Tol. ± Code nom. Tol. ± Code nom. Tol. ±
0018 1,8 0,04 0100 10,0 0,15 0,135 0365 36,5 0,31 0,45
0020 2,0 0106 10,6 0,14 0375 37,5 0,46
0,16 0,32
0022 2,24 0,05 0112 11,2 0,15 0387 38,7 0,47
0025 2,5 0118 11,8 0,16 0400 40,0 0,33 0,49
0028 2,8 0125 12,5 0,17 0,165 0412 41,2 0,34 0,50
0,055
0031 3,15 0132 13,2 0,17 0425 42,5 0,51
0,35
0035 3,55 0140 14,0 0,18 0437 43,7 0,525
0,06 0,18
0037 3,75 0150 15,0 0,19 0450 45,0 0,36 0,54
0040 4,0 0160 16,0 0,19 0,20 0475 47,5 0,38 0,57
0,13
0,07
0045 4,5 0170 17,0 0,22 0500 50,0 0,39 0,60
0,20
0048 4,87 0180 18,0 0,23 0530 53,0 0,41 0,63
0050 5,0 0190 19,0 0,24 0560 56,0 0,42 0,67
0,08 0,21
0051 5,15 0200 20,0 0,25 0600 60,0 0,45 0,71
0053 5,3 0212 21,2 0,22 0,27 0630 63,0 0,46 0,75
0056 5,6 0,09 0224 22,4 0,23 0,28 0670 67,0 0,49 0,80
0060 6,0 0236 23,6 0,30 0710 71,0 0,51 0,85
0,24
0063 6,3 0,10 0250 25,0 0,31 0750 75,0 0,53 0,89
0067 6,7 0258 25,8 0,32 0800 80,0 0,56 0,95
0,25
0069 6,9 0265 26,5 0,33 0
...
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