SIST EN 148-1:2019

Respiratory protective devices - Threads for facepieces - Part 1: Standard thread connection

This document specifies standard threads for respiratory protective devices and the description of test devices necessary for the assessment of some of the requirements.
This document does not apply to diving equipment and to positive pressure demand breathing apparatus.

Atemschutzgeräte - Gewinde für Atemanschlüsse - Teil 1: Rundgewindeanschluss

Dieses Dokument legt Rundgewinde für Atemschutzgeräte sowie die Beschreibung der für die Bewertung ei¬niger Anforderungen erforderlichen Prüfgeräte fest.
Dieses Dokument gilt nicht für Tauchgeräte und Geräte in Überdruckausführung.

Appareils de protection respiratoire - Filetages pour pièces faciales - Partie 1 : Connexion à filetage normalisé

Le présent document spécifie les filetages normalisés pour les appareils de protection respiratoire et décrit les dispositifs d’essai nécessaires à l’évaluation de certaines des exigences.
Le présent document ne s’applique ni aux appareils de plongée ni aux appareils isolants du type à la demande à pression positive.

Oprema za varovanje dihal - Navoji na maskah - 1. del: Standardna navojna povezava

Ta dokument določa standardne navoje za opremo za varovanje dihal in opis preskusnih naprav, ki so potrebne za ocenjevanje nekaterih zahtev.
Ta dokument se ne uporablja za opremo za potapljanje in dihalne aparate, ki vzdržujejo pozitivni pritisk.

General Information

• Status: Published
• Public Enquiry End Date: 04-Sep-2017
• Publication Date: 03-Feb-2019
• ICS: 13.340.30 - Respiratory protective devices
• Technical Committee: OVP - Personal protecting equipment
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 15-Jan-2019
• Due Date: 22-Mar-2019
• Completion Date: 04-Feb-2019
• Directive: 2016/425 - Regulation (EU) 2016/425 of the European Parliament and of the Council of 9 March 2016 on personal protective equipment and repealing Council Directive 89/686/EEC
• Directive: 89/686/EEC - Council Directive 89/686/EEC of 21 December 1989 on the approximation of the laws of the Member States relating to personal protective equipment
• Mandate: M/031 - Standardization mandate to CEN/CENELEC concerning standards for Personal Protective Equipment
• Mandate: M/BC/CEN/88/7 - Order for standardization concerning Personal Protective Equipment (P.P.E.) - respiratory tract protection
• Ref Project: EN 148-1:2018 - Respiratory protective devices - Threads for facepieces - Part 1: Standard thread connection

Relations

• Replaces: SIST EN 148-1:1999 - Respiratory protective devices - Threads for facepieces - Part 1: Standard thread connection
• Effective Date: 01-Mar-2019

Overview

EN 148-1:2018 - "Respiratory protective devices - Threads for facepieces - Part 1: Standard thread connection" (CEN) defines the standard thread connection used on respiratory protective devices (RPDs). It specifies thread geometry, sealing element requirements and the test devices and procedures needed to assess compliance. The standard ensures mechanical and sealing compatibility between filters, facepieces, and other threaded respiratory components.
Note: EN 148-1:2018 supersedes EN 148-1:1999 and does not apply to diving equipment or positive pressure demand breathing apparatus.

Key topics and technical requirements

• Thread profile and dimensions: Defines the standard thread form (⌀40 × 1/7) with detailed major/minor diameters, pitch, thread height and number of threads.
• Sealing element: Requirements for an annular sealing element (external/internal diameters and thickness), retention and centring so it cannot be dislodged during normal use.
• Sealing surface options: Acceptable male sealing surfaces include flat, rounded (radius ≥ 2 mm), raised sealing ring (radius ≥ 0.3 mm), or socket sealing; internal diameter limits apply.
• Effective thread length and start of thread: Minimum effective length and rules for the first 2 mm of thread (not counted as effective thread).
• Dimensional tolerances and circularity: Circularity tolerances of 0.15 mm for male and female thread radii; GO/NO‑GO and snap gauges used to verify acceptance.
• Mechanical strength: Physical and mechanical tests include resistance to pull forces (technical change: pull force reduced to 50 N in this revision).
• Absence of geometric interference: Rules to prevent filter or facepiece bodies from invading defined clearances around the thread area.
• Testing and inspection: Detailed test methods for gauge checks, circularity, geometry, sealing element properties and pull resistance. Normative references include ISO methods for rubber hardness and compression set.

Applications and users

• Manufacturers of filters, facepieces and threaded connectors - for design, production and quality control to ensure interchangeability.
• Testing and certification laboratories - to verify compliance using GO/NO‑GO gauges, snap gauges and pull tests.
• Procurement and safety engineers - to specify compatible RPD components and ensure workplace PPE interoperability.
• Standards committees and regulatory bodies - for harmonized European implementation and national adoption.

Related standards and references

• ISO 17420-3 (basis for revision) and referenced ISO methods (e.g., ISO 48-4 for Shore hardness, ISO 815-1 for compression set).
• EN 148 series: Part 1 covers standard threads; other parts / RPD standards may address complete facepiece performance and labelling.

EN 148-1:2018 is essential when specifying or testing threaded connections on respiratory protective devices to guarantee safe, standardized mechanical and sealing interfaces across products.

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2019
1DGRPHãþD
SIST EN 148-1:1999
Oprema za varovanje dihal - Navoji na maskah - 1. del: Standardna navojna
povezava
Respiratory protective devices - Threads for facepieces - Part 1: Standard thread
connection
Atemschutzgeräte - Gewinde für Atemanschlüsse - Teil 1: Rundgewindeanschluss
Appareils de protection respiratoire - Filetages pour pièces faciales - Partie 1 :
Connexion à filetage normalisé
Ta slovenski standard je istoveten z: EN 148-1:2018
ICS:
13.340.30 Varovalne dihalne naprave Respiratory protective
devices
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 148-1
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2018
EUROPÄISCHE NORM
ICS 13.340.30 Supersedes EN 148-1:1999
English Version
Respiratory protective devices - Threads for facepieces -
Part 1: Standard thread connection
Appareils de protection respiratoire - Filetages pour Atemschutzgeräte - Gewinde für Atemanschlüsse - Teil
pièces faciales - Partie 1 : Connexion à filetage 1: Rundgewindeanschluss
normalisé
This European Standard was approved by CEN on 17 September 2018.

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 148-1:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms, definitions and symbols . 4
3.1 Terms and definitions . 4
3.2 Symbols . 5
4 Requirements . 5
4.1 Elements of thread connection. 5
4.2 Sealing element . 5
4.3 Geometry of thread profile . 5
4.3.1 General . 5
4.3.2 Circularity of threads . 6
4.3.3 Male thread connector . 7
4.3.4 Female thread connector . 9
4.3.5 Sealing element . 10
4.3.6 Absence of geometric interference . 10
4.4 Physical and mechanical requirements of the thread connection . 11
4.4.1 Resistance of the connectors to pull forces . 11
4.4.2 Physical and mechanical requirements of the sealing element . 12
5 Testing . 12
5.1 Inspection . 12
5.2 Circularity of threads . 12
5.2.1 Circularity of male threads . 12
5.2.2 Circularity of female threads . 13
5.3 Geometry of male thread connector. 13
5.4 Geometry of female thread connector . 16
5.5 Beginning of the effective thread of the male connection . 21
5.6 Resistance of the connectors to pull forces . 21

European foreword
This document (EN 148-1:2018) has been prepared by Technical Committee CEN/TC 79 “Respiratory
protective devices”, the secretariat of which is held by DIN.
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 June 2019, and conflicting national standards shall be
withdrawn at the latest by June 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.
This document supersedes EN 148-1:1999.
The following main technical changes have been made compared to EN 148-1:1999:
a) ISO 17420-3 taken as basis for the revision of EN 148-1;
b) description and additional requirements for thread connector with sockets are added;
c) sealing surface adapted and a new drawing for socket sealing included;
d) pull force in 4.4.1 reduced to 50 N;
e) Annex ZA deleted.
According to the CEN-CENELEC Internal Regulations, the national standards organisations 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.
1 Scope
This document specifies standard threads for respiratory protective devices and the description of test
devices necessary for the assessment of some of the requirements.
This document does not apply to diving equipment and to positive pressure demand breathing
apparatus.
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.
ISO 48-4, Rubber, vulcanized or thermoplastic — Determination of hardness — Part 4: Indentation
hardness by durometer method (Shore hardness)
ISO/DIS 815-1, Rubber, vulcanized or thermoplastic — Determination of compression set — Part 1: At
ambient or elevated temperatures
ISO/DIS 16972, Respiratory protective devices —Definitions of terms and pictograms
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/DIS 16972 and the following
apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
thread connection
shape and dimensions of the standard connection between RPD components with a male thread
connector and respiratory interfaces with a female thread connector
3.1.2
socket
inner component that can rotate independently of the outer male thread connector
3.2 Symbols
For the purposes of this document, the following symbols apply (see Figure 1 to Figure 20).
d major diameter of male thread
d minor diameter of male thread
d inner dimension for gauge
d outer dimension for gauge
D major diameter of female thread
D minor diameter of female thread
h pitch
t thread height
r radius
b thickness of gauge (GO gauge or NO-GO gauge)
w permissible surface degradation due to wear and tear for d1 and d2
H thickness of ring A
a
H thickness of ring B
b
4 Requirements
4.1 Elements of thread connection
The thread connection shall consist of the following three elements.
1) A male thread connector without sockets which forms the connecting element of a filter or a male
thread connector with socket for connectors other than for filters.
2) A female thread connector which forms the connecting element of the respiratory interface.
3) A sealing element which is retained within the female thread connector.
4.2 Sealing element
The sealing element shall be retained in place, correctly centred, and it shall not be possible to dislodge
it during normal use.
It shall be easy to check that the sealing element is in place (e.g. sealing element of a different colour
from the female thread connector).
Testing shall be performed in accordance with 5.1.
4.3 Geometry of thread profile
4.3.1 General
The profile of the thread shall have a diameter of 40x1/7 as defined by the female and male threads
profile geometry (Figure 1) and thread dimensions given in Table 1.
Key
1 female thread
2 male thread
Figure 1 — Geometry of thread profile
Table 1 — Thread dimensions for the mechanical connection interface
Dimensions in millimetres
Thread Male thread Female thread
No. of
threads
Thread
Pitch per Radius
height
Major Minor Major Minor 25,4 m

diameter diameter diameter diameter m
d1 d2 D1 D2
max. min. max. min. min. max. h z t1 r
⌀ 40x1/7 40,00 39,70 38,40 40,16 38,56 38,86 3,629 7 0,65 to 0,8 1,225
Testing shall be performed in accordance with 5.1, 5.3, 5.4 and 5.5.
4.3.2 Circularity of threads
4.3.2.1 General
The circularity tolerance of the threads shall be 0,15 mm referred to the major radius of the male thread
and 0,15 mm referred to the minor radius of the female thread.
4.3.2.2 Circularity of the male thread
When approached perpendicular to the axis of the thread in any angular orientation, the limit snap
gauge with single-ended jaws shall not pass over the thread (see Figure 8).
Testing shall be performed in accordance with 5.2.1.
4.3.2.3 Circularity of the female thread
When approached parallel to the axis of the thread in any angular orientation, the sector NO-GO gauge
shall not enter the thread (see Figure 9).
Testing shall be performed in accordance with 5.2.2.
4.3.3 Male thread connector
4.3.3.1 General
The material used for the male thread connector and its thickness is left to the manufacturer's choice.
4.3.3.2 Sealing surface
The shape of the sealing surface of the male thread connector shown in Figure 2 with the enlarged
detail of Figures 2 a, 2 b, 2 c, 2 d that interfaces with the sealing element, is left to the manufacturer’s
c
...