FprEN ISO 3821

Gas welding equipment - Rubber hoses for welding, cutting and allied processes (ISO/FDIS 3821:2017)

Gasschweißgeräte — Gummischläuche für Schweißen, Schneiden und verwandte Prozesse (ISO/FDIS 3821:2017)

Dieses Dokument legt Anforderungen für Gummischläuche (einschließlich Doppelschläuchen) für Schweißen, Schneiden und verwandte Prozesse fest. Es gilt für Gummischläuche normaler Klasse bis zu 2 MPa (20 bar) und für Gummischläuche leichter Klasse [beschränkt auf Schläuche für einen höchsten Betriebsdruck von bis zu 1 MPa (10 bar) und mit einer Nennweite von kleiner oder gleich 6,3 mm] im Temperaturbereich von −20 °C bis +60 °C eingesetzt werden bei:
—   Gasschweißen und Schneiden;
—   Lichtbogenschweißen unter dem Schutz eines inerten oder aktiven Gases; und
—   verwandte Prozesse zum Schweißen und Schneiden, insbesondere Wärmen, Hartlöten und Spritzen.
Dieses Dokument legt keine Anforderungen an Schlauchleitungen fest; diese werden in ISO 8207 ausführlich beschrieben.
Es gilt weder für thermoplastische Schläuche, noch für Schläuche, die für Hoch¬druckacetylen [> 0,15 MPa (> 1,5 bar)] verwendet werden.

Matériel de soudage aux gaz - Tuyaux souples en caoutchouc pour le soudage, le coupage et les techniques connexes (ISO/FDIS 3821:2017)

Oprema za plamensko varjenje - Gumene cevi za varjenje, rezanje in sorodne postopke (ISO/FDIS 3821:2017)

General Information

• Status: Not Published
• Publication Date: 01-Jan-2018
• Withdrawal Date: 01-Jul-2018
• ICS: 23.040.70 - Hoses and hose assemblies
• ICS: 25.160.30 - Welding equipment
• ICS: 27.070 - Fuel cells
• ICS: 83.140.40 - Hoses
• Technical Committee: CEN/TC 121 - Welding
• Drafting Committee: CEN/TC 121/WG 19 - Equipment for gas welding, cutting and allied processes
• Current Stage: 5098 - Decision to abandon - Formal Approval
• Start Date: 25-Sep-2019
• Completion Date: 14-Apr-2025
• Ref Project: kSIST FprEN ISO 3821:2017 - Gas welding equipment - Rubber hoses for welding, cutting and allied processes (ISO/FDIS 3821:2017)

Relations

• Revises: EN ISO 3821:2010 - Gas welding equipment - Rubber hoses for welding, cutting and allied processes (ISO 3821:2008)
• Effective Date: 08-Jun-2022

Overview

The FprEN ISO 3821 standard, titled Gas Welding Equipment - Rubber Hoses for Welding, Cutting and Allied Processes (ISO/FDIS 3821:2017), specifies stringent requirements for rubber hoses used in gas welding, cutting, and related applications. Developed by the International Organization for Standardization (ISO) and the European Committee for Standardization (CEN), this standard ensures safety and performance consistency in rubber hoses designed for various industrial uses involving gas welding equipment.

This standard addresses hoses categorized as light and normal duty with maximum working pressures up to 20 bar (2 MPa), covering operational temperature ranges from -20°C to +60°C. It applies to hoses including single and twin rubber hoses intended for use with oxygen, acetylene, universal fuel gases, and flux fuel gases in welding, cutting, brazing, metallization, and similar thermal processes.

Key Topics

1. Hose Construction and Materials

The standard outlines construction details for light and normal duty hoses, emphasizing:

• Minimum rubber lining thickness of 1.5 mm.
• Reinforcement methods ensuring durability under pressure.
• Rubber cover thickness of at least 1.0 mm for protection against external damage.
• Special provisions for flux fuel gas hoses, which include an additional inner plastic layer to resist chemical fluxes.

2. Hose Designation and Marking

Hoses are clearly designated by:

• Inside diameter (e.g., 6.3 mm).
• Pressure rating (light duty or normal duty).
• Hose color coding and markings to identify gas compatibility, enhancing safety in the workplace.

3. Performance Requirements and Testing

Rubber hoses must pass rigorous type tests to meet performance criteria such as:

• Tensile strength and elongation at break for durability.
• Accelerated ageing and resistance to heat.
• Hydrostatic pressure tests to confirm maximum working pressure capability.
• Flexibility tests over the specified temperature range to ensure usability in diverse conditions.
• Resistance to ozone, hot surfaces, and potential ignition sources.
• Specialized chemical resistance tests for acetylene and flux fuel gas hoses, including resistance to acetone, dimethylformamide (DMF), n-pentane, and trimethylborate-methanol azeotrope.

4. Scope and Application Restrictions

• Intended for gas welding and cutting, arc welding with protective gases, and ancillary processes such as brazing and metallization.
• Excludes thermoplastic hoses and high-pressure acetylene hoses above 0.15 MPa.
• Specifies that hose assemblies are covered by other standards (e.g., ISO 8207).

Applications

FprEN ISO 3821 compliant hoses are essential in:

• Gas welding and cutting operations in manufacturing, construction, automotive repair, and metal fabrication industries.
• Arc welding processes that utilize inert or active gas shielding.
• Allied thermal processes, including brazing and metallization, which require reliable and safe gas supply lines.
• Environments demanding hoses that resist harsh chemical exposure and mechanical stress, maintaining safety standards and operational integrity.

By adhering to this standard, manufacturers and users ensure optimal hose performance, reduce risks of gas leaks or hose failure, and maintain workplace safety.

Related Standards

FprEN ISO 3821 references and works in conjunction with several other international standards, including:

• ISO 8207 - Specifies requirements for welding hose assemblies.
• ISO 37 - Tensile stress-strain properties of rubber.
• ISO 188 - Accelerated aging and heat resistance of rubber.
• ISO 1402 - Hydrostatic testing of rubber and plastic hoses.
• ISO 1817 - Determination of the effect of liquids on rubber.
• ISO 11114-3 - Autogenous ignition tests for materials in oxygen atmospheres.
• ISO 8330 - Vocabulary for rubber and plastic hoses.
• ISO 10619-1 and ISO 10619-2 - Flexibility and stiffness testing at various temperatures.

These standards collectively reinforce the quality, safety, and reliability of welding equipment and accessories.

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Keywords: ISO 3821, rubber hoses, gas welding equipment, welding hoses, cutting hoses, flux fuel gas hose, twin hose, welding hose standard, welding safety, hose construction, hose performance testing, gas identification, industrial hoses, welding accessories.

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN ISO 3821:2016
01-oktober-2016
Oprema za plamensko varjenje - Gumene cevi za varjenje, rezanje in sorodne
postopke (ISO/DIS 3821:2016)
Gas welding equipment - Rubber hoses for welding, cutting and allied processes
(ISO/DIS 3821:2016)
Gasschweißgeräte - Gummischläuche für Schweißen, Schneiden und verwandte
Prozesse (ISO/DIS 3821:2016)
Matériel de soudage aux gaz - Tuyaux souples en caoutchouc pour le soudage, le
coupage et les techniques connexes (ISO/DIS 3821:2016)
Ta slovenski standard je istoveten z: prEN ISO 3821
ICS:
25.160.30 Varilna oprema Welding equipment
83.140.40 Gumene cevi Hoses
oSIST prEN ISO 3821:2016 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN ISO 3821:2016
oSIST prEN ISO 3821:2016
DRAFT INTERNATIONAL STANDARD
ISO/DIS 3821
ISO/TC 44/SC 8 Secretariat: DIN
Voting begins on: Voting terminates on:
2016-08-25 2016-11-16
Gas welding equipment — Rubber hoses for welding,
cutting and allied processes
Matériel de soudage aux gaz — Tuyaux souples en caoutchouc pour le soudage, le coupage et les
techniques connexes
ICS: 83.140.40; 25.160.30
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 3821:2016(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2016

oSIST prEN ISO 3821:2016
ISO/DIS 3821:2016(E)
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
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ii © ISO 2016 – All rights reserved

oSIST prEN ISO 3821:2016
ISO/DIS 3821:2016(E)
Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Abbreviated terms . 2
5 Application . 2
6 Hose designation . 2
7 Materials . 3
7.1 Construction . 3
7.1.1 Light and normal duty hoses . 3
7.1.2 Flux fuel gas hose . 3
7.1.3 Twin hose . 3
7.2 Manufacture . 3
8 Dimensions and tolerances . 3
8.1 Inside diameter . 3
8.2 Concentricity (total indicator reading) . 3
8.3 Cut lengths and tolerances . 4
9 Requirements and type tests . 4
9.1 General . 4
9.2 Basic requirements . 4
9.2.1 Tensile strength and elongation at break . 4
9.2.2 Accelerating ageing . . 5
9.2.3 Adhesion . 5
9.2.4 Hydrostatic requirements . 5
9.2.5 Flexibility at ambient temperature . 5
9.2.6 Low-temperature flexibility . 5
9.2.7 Protection against incandescent particles and hot surfaces . 5
9.2.8 Ozone resistance . 5
9.3 Special requirements . 6
9.3.1 Non-ignition requirement for oxygen hoses . 6
9.3.2 Resistance to acetone and dimethylformamide for acetylene hoses . 6
9.3.3 Resistance to n-pentane . 6
9.3.4 Resistance to azeotrope of trimethylborate with methanol for flux fuel gas hoses 6
9.3.5 Flexibility of flux fuel gas hoses . 7
9.3.6 Permeability to LPG, MPS, and natural gas of methane hoses, universal
fuel gas hoses, and flux fuel gas hoses . 7
9.3.7 Requirements for twin hoses . 7
9.3.8 Requirements for universal fuel gas hose . 7
10 Hose colour and gas identification . 7
10.1 General . 7
10.2 Gas identification . 7
10.3 Marking . 8
Annex A (normative) Method of test for non-ignition . 9
Annex B (normative) Method of test for resistance to acetone and dimethylformamid (DMF) .11
Annex C (normative) Method of test for resistance to n-pentane .12
Annex D (normative) Method of test for resistance to incandescent particles and hot surfaces .13
Annex E (normative) Summary of requirements and type tests .15
Annex F (normative) Alternative oxygen gas colour codes .16
oSIST prEN ISO 3821:2016
ISO/DIS 3821:2016(E)
Bibliography .17
iv © ISO 2016 – All rights reserved

oSIST prEN ISO 3821:2016
ISO/DIS 3821:2016(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment,
as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the
Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.
The committee responsible for this document is ISO/TC 44/SC 8.
This fifth edition cancels and replaces the fourth edition which has been technically revised.
The main changes from ISO 3821:2008, 10 are:
a) Definition of maximum working pressure added;
b) Title of 7.1.1 changed from “General” to “Light and normal duty hose”
c) Table 1 “Wall thickness, inside diameter, tolerances and concentricity” revised;
d) 9.3.2 “Resistance to acetone and DMF revised;
e) 9.3.4.1 “Adhesion after conditioning in trimethylborate-methanol azeotrope” revised;
f) Requirements for marking revised;
g) New Annex B “Method of test for resistance to acetone and dimethylformamid (DMF)” added;
h) Standard editorially revised.
oSIST prEN ISO 3821:2016
oSIST prEN ISO 3821:2016
DRAFT INTERNATIONAL STANDARD ISO/DIS 3821:2016(E)
Gas welding equipment — Rubber hoses for welding,
cutting and allied processes
1 Scope
This International Standard specifies requirements for rubber hoses (including twin hoses) for welding,
cutting and allied processes.
This International Standard specifies requirements for rubber hoses for normal duty of 2 MPa (20 bar)
and light duty [limited to hoses for maximum working pressure of 1 MPa (10 bar) and with bore up to
and including 6,3 mm].
This International Standard applies to hoses operated at temperatures −20 °C to +60 °C and used in:
— gas welding and cutting;
— arc welding under the protection of an inert or active gas;
— processes allied to welding and cutting, in particular, heating, brazing, and metallization.
This standard does not specify requirements for hose assemblies; these are detailed in ISO 8207.
This International Standard applies neither to thermoplastics hoses nor to hoses used for high pressure
[>0,15 MPa (>1,5 bar)] acetylene.
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 37, Rubber, vulcanized or thermoplastic — Determination of tensile stress-strain properties
ISO 188, Rubber, vulcanized or thermoplastic — Accelerated ageing and heat resistance tests
ISO 1307:2006, Rubber and plastics hoses — Hose sizes, minimum and maximum inside diameters, and
tolerances on cut-to-length hoses
ISO 1402, Rubber and plastics hoses and hose assemblies — Hydrostatic testing
ISO 10619-1, Rubber and plastics hoses and tubing — Measurement of flexibility and stiffness — Part 1:
Bending tests at ambient temperature
ISO 10619-2, Rubber and plastics hoses and tubing — Measurement of flexibility and stiffness — Part 2:
Bending tests at sub-ambient temperatures
ISO 1817, Rubber, vulcanized or thermoplastic — Determination of the effect of liquids
ISO 4080, Rubber and plastics hoses and hose assemblies — Determination of permeability to gas
ISO 4671, Rubber and plastics hoses and hose assemblies — Methods of measurement of the dimensions of
hoses and the lengths of hose assemblies
ISO 10619-1, Rubber and plastics hoses and tubing — Measurement of flexibility and stiffness — Part 1:
Bending tests at ambient temperature
ISO 7326:2006, Rubber and plastics hoses — Assessment of ozone resistance under static conditions
oSIST prEN ISO 3821:2016
ISO/DIS 3821:2016(E)
ISO 8033:2006, Rubber and plastics hoses — Determination of adhesion between components
ISO 8330, Rubber and plastics hoses and hose assemblies — Vocabulary
ISO 11114-3, Gas cylinders — Compatibility of cylinder and valve materials with gas contents — Part 3:
Autogenous ignition test for non-metallic materials in oxygen atmosphere
ISO 23529, Rubber — General procedures for preparing and conditioning test pieces for physical test methods
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 8330 and ISO 15296 and the
following apply.
3.1
twin hose
two normal rubber hoses joined together longitudinally
3.2
universal fuel gas hose
hoses which can be used for all fuel gases except fluxed fuel gas
Note 1 to entry: Fuel gases are listed in Table 4.
3.3
flux fuel gas hose
hose suitable for fuel gas containing a flux
3.4
maximum working pressure
maximum pressure to which the equipment may be subjected in service
4 Abbreviated terms
For the purposes of this document, the following abbreviations apply.
LPG liquefied petroleum gases
MPS methylacetylene-propadiene mixtures
5 Application
Hoses shall only be used for the gas service for which they are identified (see 10.2).
6 Hose designation
The hoses covered by this International Standard are designated using the following information:
a) inside diameter, see Table 1;
b) light or normal duty (pressure rating), see Table 3;
c) colour and marking (gas service), see Table 4.
EXAMPLE 1 6,3 mm, light duty. Blue (Oxygen).
EXAMPLE 2 10 mm, normal duty. Red/Orange (Universal fuel gases).
EXAMPLE 3 6,3 mm, light duty, FLUX. Red (Fluxed fuel gases).
2 © ISO 2016 – All rights reserved

oSIST prEN ISO 3821:2016
ISO/DIS 3821:2016(E)
7 Materials
7.1 Construction
7.1.1 Light and normal duty hoses
The hose shall consist of:
a) a rubber lining of minimum thickness 1,5 mm;
b) reinforcement applied by any suitable technique;
c) a rubber cover of a minimum thickness of 1,0 mm.
7.1.2 Flux fuel gas hose
The flux fuel gas hose shall consist of:
a) a rubber lining with an additional inner plastic layer, which shall be of maximum thickness 0,5 mm,
to give a minimum total thickness of 1,5 mm;
b) reinforcement applied by any suitable technique;
c) a rubber cover of minimum thickness 1,0 mm.
7.1.3 Twin hose
Each hose used for twin hose construction shall be as specified in 7.1.1 or 7.1.2. The two hoses shall be
joined longitudinally during the extrusion and/or vulcanization process. They shall be capable of being
separated free of damage to enable end fittings to be fitted. See 9.3.7.
7.2 Manufacture
The lining and cover shall be of uniform thickness and free from holes, porosity and other defects.
8 Dimensions and tolerances
8.1 Inside diameter
The inside diameter of the hoses shall be in accordance with the dimensions and tolerances shown in
Table 1.
8.2 Concentricity (total indicator reading)
The concentricity of the hose, measured in accordance with ISO 4671, shall be in accordance with the
values given in Table 1.
oSIST prEN ISO 3821:2016
ISO/DIS 3821:2016(E)
Table 1 — Wall thickness, inside diameter, tolerances and concentricity
Inside diameter Tolerance Outside diameter Tolerance Concentricity max.
mm mm mm mm mm
4,0 10,0
4,8 10,8
5,0 ±0,3 11,0 ±0,4 0,7
6,3 12,0
7,1 13,1
8,0 14,0
9,5 ±0,4 16,5 ±0,5 0,8
10,0 17,0
12,5 20,0
16,0 23,5
±0,5 ±0,6
20,0 27,5
25,0 33,0 1,0
32,0 44,0
40,0 ±0,8 54,0 ±1,0
50,0 66,0
NOTE 1  The tolerance
...