EN 4835:2018
(Main)Aerospace series - Installation and removal requirements for Ring locked fitting and reducer, 24° Cone up to 35 000 kPa (5 080 psi) - Inch Series
Aerospace series - Installation and removal requirements for Ring locked fitting and reducer, 24° Cone up to 35 000 kPa (5 080 psi) - Inch Series
This European Standard specifies the installation and removal requirements for adaptors and
reducers, threaded, with lockring for pipe couplings 24° according to EN 4833 and EN 4836.
This standard establishes an accurate procedure of adaptor installation, removal and reinstallation to
ensure the repeatability of the installation operation and to ensure the effective compliance to sealing
and locking requirements.
The adaptor shown on all Figures of this standard is given as an example for the 24° internal cone
interface according to EN 6123.
This procedure is used for adaptors 24°, for nominal pressure up to 35 000 kPa (5 080 psi).
Luft- und Raumfahrt - In- und Ausbaubedingungen für Anschlussverschraubung und Reduzierer mit Sicherungsring 24° Konus bis 35 000 kPa (5 080 psi) - Inch-Reihe
Diese Europäische Norm legt die Ein- und Ausbaubedingungen für Adapter und Reduzierer mit Gewinde und
Sicherungsring für 24°-Rohrverbindungen nach EN 4833 und EN 4836 fest.
Diese Norm legt ein genaues Verfahren des Adaptereinbaus, -ausbaus und -wiedereinbaus fest, um die
Wiederholbarkeit des Einbauverfahrens sicherzustellen und um die wirksame Einhaltung der Dichtungsund
Verriegelungsanforderungen sicherzustellen.
Der in allen Bildern dieser Norm gezeigte Adapter dient als Beispiel für den 24°-Innenkonus nach EN 6123.
Dieses Verfahren wird für 24°-Adapter und für Nenndrücke bis zu 35 000 kPa (5 080 psi) verwendet.
Série aérospatiale - Spécification de montage et démontage des raccords à implanter avec bague de sécurité, interface conique 24° jusqu'à 35 000 kPa (5 080 psi) - Série inch
Aeronavtika - Zahteve za namestitev in odstranitev navojnega priključka z zapornim obročem in njegovega reduktorja, 24°, konica do 35 000 kPa (5080 psi) - Palčne mere
Ta evropski standard določa zahteve za namestitev in odstranitev adapterjev in navojnih priključkov z zapornim obročem in reduktorjem priključka, 24°, v skladu s standardoma EN 4833 in EN 4836. Ta standard določa natančen postopek namestitve, odstranitve in ponovne namestitve adapterjev, da se zagotovi ponovljivost postopka namestitve in učinkovitost skladnosti z zahtevami za tesnjenje in zaklepanje.
Adapter, prikazan na vseh slikah tega standarda, je podan kot primer za 24° vmesnik notranje konice v skladu s standardom EN 6123.
Ta postopek se uporablja za adapterje 24° pri nazivnem tlaku do 35 000 kPa (5080 psi).
General Information
- Status
- Published
- Publication Date
- 31-Jul-2018
- Withdrawal Date
- 27-Feb-2019
- Technical Committee
- ASD-STAN - Aerospace
- Drafting Committee
- ASD-STAN/D 3/S 3 - Hydraulics
- Current Stage
- 6060 - Definitive text made available (DAV) - Publishing
- Start Date
- 01-Aug-2018
- Completion Date
- 01-Aug-2018
Overview
EN 4835:2018 - "Aerospace series - Installation and removal requirements for Ring locked fitting and reducer, 24° Cone up to 35 000 kPa (5 080 psi) - Inch Series" - provides detailed, repeatable procedures for installing, removing and reinstalling 24° ring‑locked adaptors and reducers used in high‑pressure aerospace fluid systems. The standard targets inch‑series, extra‑fine thread fittings and covers steps that ensure reliable metal‑to‑metal sealing with O‑rings, correct lockring engagement and prevention of fitting rotation during service.
Key topics and technical requirements
- Scope and intent: Procedures to ensure repeatability of installation operations and compliance with sealing and locking requirements for adaptors and reducers up to 35 000 kPa (5 080 psi).
- Seal and materials: Metal‑to‑metal sealing with specified O‑ring sizes; O‑ring compound selection left to the design activity. Compatible with titanium across −54 °C to +135 °C (−65 °F to +230 °F).
- Port preparation: Prescribed sequence - tap drilling, port machining, serration broaching, and thread cutting - with dimensions and tolerances referenced to the standard.
- Installation process: Hand start of adaptor, use of certified special tooling (combination wrench/drive tool), controlled torque application to engage lockring serrations, primer application to counterbore to prevent galvanic corrosion where required.
- Lockring function: Lockring is driven into port serrations after torqueing to prevent fitting rotation during coupling nut assembly/disassembly, allowing single‑wrench installation/removal.
- Tooling and qualification: Special installation tools must be certified and qualified for each manufacturing sequence, port material and pressure rating.
- Units and equivalents: While using SI units, inch‑pound dimensions are provided (decimal point used for inch units). EN 4835 is a functional equivalent of AS5551; coordination with SAE is noted.
Applications and who uses it
EN 4835:2018 is intended for:
- Aerospace design engineers specifying fluid system interfaces
- Manufacturing and assembly technicians performing port preparation and adaptor installation
- Maintenance and overhaul personnel carrying out removal and reinstallation
- Quality, inspection and certification teams validating installation processes
- Suppliers of adaptors, reducers and special installation tooling
Typical applications include high‑pressure aircraft hydraulic and fluid lines requiring reliable, semi‑permanent ring‑locked fittings where repeatable sealing and locking are critical.
Related standards
- EN 4833, EN 4834, EN 4836 - associated 24° coupling/adaptor/reducer geometric and coupling specifications
- EN 6123 - 24° internal cone fitting end design
- ISO 3161, ISO 16031-1 - thread and O‑ring size/tolerance references
- AS5551 - functional equivalent (co‑owned; coordinated revisions)
Keywords: EN 4835:2018, ring locked fitting, 24° cone, adaptor installation, reducer, aerospace fluid systems, O‑ring seal, serration broaching, port preparation, high‑pressure fittings.
Frequently Asked Questions
EN 4835:2018 is a standard published by the European Committee for Standardization (CEN). Its full title is "Aerospace series - Installation and removal requirements for Ring locked fitting and reducer, 24° Cone up to 35 000 kPa (5 080 psi) - Inch Series". This standard covers: This European Standard specifies the installation and removal requirements for adaptors and reducers, threaded, with lockring for pipe couplings 24° according to EN 4833 and EN 4836. This standard establishes an accurate procedure of adaptor installation, removal and reinstallation to ensure the repeatability of the installation operation and to ensure the effective compliance to sealing and locking requirements. The adaptor shown on all Figures of this standard is given as an example for the 24° internal cone interface according to EN 6123. This procedure is used for adaptors 24°, for nominal pressure up to 35 000 kPa (5 080 psi).
This European Standard specifies the installation and removal requirements for adaptors and reducers, threaded, with lockring for pipe couplings 24° according to EN 4833 and EN 4836. This standard establishes an accurate procedure of adaptor installation, removal and reinstallation to ensure the repeatability of the installation operation and to ensure the effective compliance to sealing and locking requirements. The adaptor shown on all Figures of this standard is given as an example for the 24° internal cone interface according to EN 6123. This procedure is used for adaptors 24°, for nominal pressure up to 35 000 kPa (5 080 psi).
EN 4835:2018 is classified under the following ICS (International Classification for Standards) categories: 49.080 - Aerospace fluid systems and components. The ICS classification helps identify the subject area and facilitates finding related standards.
You can purchase EN 4835:2018 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-oktober-2018
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Aerospace series - Installation and removal requirements for Ring locked fitting and
reducer, 24° Cone up to 35 000 kPa (5 080 psi) - Inch Series
Luft- und Raumfahrt - In- und Ausbaubedingungen für Anschlussverschraubung und
Reduzierer mit Sicherungsring 24° Konus bis 35 000 kPa (5 080 psi) - Inch-Reihe
Série aérospatiale - Spécification de montage et démontage des raccords à implanter
avec bague de sécurité, interface conique 24° jusqu'á 35 000 kPa (5 080 psi) - Série inch
Ta slovenski standard je istoveten z: EN 4835:2018
ICS:
49.080 /HWDOVNLLQYHVROMVNL Aerospace fluid systems and
KLGUDYOLþQLVLVWHPLLQGHOL components
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 4835
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2018
EUROPÄISCHE NORM
ICS 49.080
English Version
Aerospace series - Installation and removal requirements
for Ring locked fitting and reducer, 24° Cone up to 35 000
kPa (5 080 psi) - Inch Series
Série aérospatiale - Spécification de montage et Luft- und Raumfahrt - In- und Ausbaubedingungen für
démontage des raccords à implanter avec bague de Anschlussverschraubung und Reduzierer mit
sécurité, interface conique 24° jusqu'á 35 000 kPa (5 Sicherungsring 24° Konus bis 35 000 kPa (5 080 psi) -
080 psi) - Série inch Inch-Reihe
This European Standard was approved by CEN on 3 December 2017.
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-CENELEC 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-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 4835:2018 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Installation instructions . 6
4 Replacement instructions . 14
Bibliography . 17
European foreword
This document (EN 4835:2018) 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 February 2019, and conflicting national standards
shall be withdrawn at the latest by February 2019.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
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,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.
Introduction
This European Standard is co-owned standard and a functional equivalent of AS5551. There should be
no technical objection to use AS5551 as replacement of EN 4835 parts. Further revisions to this
standard shall be coordinated with the SAE committee.
European standards use the International System of units (SI); however, large segments of the
aerospace industry make use of other measurement systems as a matter of common working practice.
All dimensions and units used in this standard are given in SI units, with other units also indicated for
the convenience of the user.
The decimal sign used in International standards is the comma (“,”); however, the comma is not used
in common working practice with non-SI dimensions. Therefore, in common with many other
aerospace standards, the decimal point (“.”) is used in this standard when providing dimensions in
inch-pound units.
NOTE The use of non-SI units and the decimal point in this standard does not constitute general acceptance
of measurement systems other than SI within European standards.
1 Scope
This European Standard specifies the installation and removal requirements for adaptors and
reducers, threaded, with lockring for pipe couplings 24° according to EN 4833 and EN 4836.
This standard establishes an accurate procedure of adaptor installation, removal and reinstallation to
ensure the repeatability of the installation operation and to ensure the effective compliance to sealing
and locking requirements.
The adaptor shown on all Figures of this standard is given as an example for the 24° internal cone
interface according to EN 6123.
This procedure is used for adaptors 24°, for nominal pressure up to 35 000 kPa (5 080 psi).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
EN 2435-001, Aerospace series — Paints and varnishes — Corrosion resistant chromated two component
cold curing primer — Part 001: Minimum requirements
EN 4833, Aerospace series — Pipe coupling 24° Cone up to 35 000 kPa (5 080 psi) Ring-locked fitting —
1)
Flared End — Inch Series — with Extra Fine Thread Pitch
EN 4834, Aerospace series — Adaptor, Pipe coupling 24° Cone up to 35 000 kPa (5 080 psi) Port for Ring
1)
locked fitting — Inch Series — Geometric configuration
EN 4836, Aerospace series — Adaptor, Pipe coupling 24° Cone up to 35 000 kPa (5 080 psi) Ring-locked
1)
fitting Reducer — Flared End — with Extra Fine Thread Pitch — Inch Series
EN 6123, Aerospace series — Fitting end, 24° internal cone, external thread, flareless type — Extra fine
thread pitch — Inch series — Design standard
ISO 3161, Aerospace — UNJ threads — General requirements and limit dimensions
ISO 16031-1, Aerospace fluid systems — O-rings, inch series: Inside diameters and cross sections,
tolerances and size-identification codes — Part 1: Close tolerances for hydraulic systems
2)
AS8879, Screw threads — UNJ profile, inch controlled radius root with increased minor diameter
1) Published as ASD-STAN Prestandard at the date of publication of this standard (www.asd-stan.org).
2) Published by: SAE International (www.sae.org).
3 Installation instructions
3.1 Engineering information
Key
1 The fitting assemblies according to EN 4833 and the fitting reducer according to EN 4836
provide a semi-permanent male fitting for use in fluid systems of 35 000 kPa (5 080 psi) and
compatible with titanium at −54 °C to +135 °C (−65 °F to +230 °F) temperature range.
2 The lockring is driven into the mating port serrations after the fitting assembly or fitting reducer
assembly have been torqued. This prevents the fitting assembly from rotating in the port during
coupling nut assembly and disassembly and also eliminates the necessity of lock wiring the fitting.
Only one wrench is required to install or remove coupling nut.
3 Seal is metal to metal with O-ring size according to Table 1. O-ring material compound shall be
selected and specified by the using design activity and shall be selected based upon suitability
with fluid type and temperature range.
4 Tapped hole (boss port side) for the 24° adaptor installation.
5 Port side interface of the adaptor according to “3.2 Port preparation”.
6 Thread A
7 Thread B
Figure 1
Table 1 — General information – Ring locked fitting
Dimensions in millimetres
b b
O-ring size code
Thread A Thread B
24°
Adaptor part no. X
coupling (as per
ISO 3161 ISO 3161
(as per EN 4833) max.
a
ISO 16031-1)
code
Class 3A Class 3A
04 04 0.4375 − 28UNJEF 0.3125 − 24UNJF 010 3,15
06 06 0.5625 − 24UNJEF 0.4375 − 20UNJF 012
08 08 0.7500 − 20UNJEF 0.5625 − 18UNJF 014 3,30
10 10 0.8750 − 20UNJEF 0.6875 − 24UNJEF 016
12 12 1.0625 − 18UNJEF 0.8125 − 20UNJEF 018
16 16 1.3125 − 16UNJ 1.1250 − 18UNJEF 022 3,56
20 20 1.6250 − 16UNJ 1.3125 − 18UNJEF 026
a Size code corresponds to the nominal tube diameter in 1/16 inch.
b For information only, please refer to EN 6123.
3.2 Port preparation
3.2.1 General
The manufacturing sequence of port preparation is for information only.
Qualification of the assembly is required for each manufacturing sequence and type of tool for a given
port material installation method and nominal pressure.
The
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