CEN/TR 16940:2016

Domestic gas installations - Recommendations for safety

This Technical Report gives recommendations to ensure the quality and safety of domestic gas installations. This Technical Report covers pipe work, appliances installation, their combustion air supply and flue products exhaust commissioning, inspection and maintenance activities carried out by operatives.
This document addresses the following three main factors, which have an influence on gas safety in general:
a)   quality and safety of components of gas installations and gas appliances,
b)   quality of the work when gas installations are constructed and commissioned,
c)   inspection and maintenance of installations and gas appliances.
Potential ways in which individual competence of operatives and/or businesses can be ensured and mutually recognized between Member States are considered.
The means of assuring responsible behaviour of consumers is not covered in this document.
It does not address metering or non-domestic (industrial and commercial) installations.

Gas Installationen in Haushalten - Empfehlungen für die Sicherheit

Installations intérieures de gaz - Recommandations pour la sécurité

Le présent Rapport technique donne des recommandations visant à assurer la qualité et la sécurité des installations intérieures de gaz. Il couvre les activités de tuyauterie, d'installation d'appareils, de mise en service des systèmes d'alimentation en air de combustion et d'évacuation des produits de combustion associés, d'inspection et de maintenance menées par les opérateurs.
Le présent document aborde les trois facteurs ci-dessous, qui ont une influence sur la sécurité du gaz en général :
a)   la qualité et la sécurité des éléments des installations de gaz et des appareils à gaz ;
b)   la qualité des travaux de construction et de mise en service des installations de gaz ;
c)   l'inspection et la maintenance des installations et des appareils à gaz.
Le présent document explore différentes options possibles pour la vérification et la reconnaissance mutuelle des compétences des opérateurs et/ou des entreprises d'un État membre à l'autre.
Le présent document ne traite pas des moyens de garantir une attitude responsable de la part des utilisateurs.
Le présent document n'aborde pas non plus les systèmes de comptage ni les installations à usage non domestique (industrielles et commerciales).

Gospodinjske plinske napeljave - Priporočila za varnost

To tehnično poročilo podaja priporočila za zagotovitev kakovosti in varnosti gospodinjskih plinskih napeljav. To tehnično poročilo zajema inštalacijske cevi, namestitev aparatov, začetek obratovanja izpušnih sistemov izdelkov za dovod zraka za izgorevanje in zračnikov, pregled in aktivnosti vzdrževanja, ki jih izvajajo izvajalci.
Ta dokument obravnava naslednje tri glavne dejavnike, ki vplivajo na splošno plinsko varnost:
a) kakovost in varnost komponent plinskih napeljav in plinskih naprav,
b) kakovost dela pri gradnji plinskih napeljav in njihovemu začetku obratovanja,
c) pregled in vzdrževanje napeljav in plinskih naprav.
Upoštevani so možni načini zagotavljanja usposobljenosti izvajalcev in/ali podjetij, ki jih medsebojno priznavajo države članice.
Sredstva za zagotavljanje odgovornega vedenja potrošnikov niso zajeta v tem dokumentu.
Ne obravnava merilnih ali negospodinjskih (industrijskih ali komercialnih) napeljav.

General Information

• Status: Published
• Publication Date: 06-Dec-2016
• ICS: 91.140.40 - Gas supply systems
• Technical Committee: CEN/TC 234 - Gas infrastructure
• Drafting Committee: CEN/TC 234 - Gas infrastructure
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 07-Dec-2016
• Due Date: 03-Jul-2016
• Completion Date: 07-Dec-2016
• Ref Project: SIST-TP CEN/TR 16940:2017 - Domestic gas installations - Recommendations for safety

Overview

CEN/TR 16940:2016 - "Domestic gas installations - Recommendations for safety" is a CEN Technical Report giving practical recommendations to ensure the quality and gas safety of domestic gas installations. It covers pipework, appliance installation, combustion air supply, flue products exhaust, commissioning, inspection and maintenance activities carried out by operatives. The document focuses on three main safety factors:

• quality and safety of components,
• quality of construction and commissioning work, and
• inspection and maintenance of installations and appliances.

The report also considers ways to assure and mutually recognize the competence of operatives and businesses across Member States. It does not cover metering or non‑domestic (industrial/commercial) installations.

Key Topics

• Scope and definitions relevant to domestic gas installations and safety practice.
• Assuring quality of installation and service work, including the role of competent operatives and organizations.
• Pipework requirements: design, sizing, installation, testing, commissioning and maintenance guidance based on EN 1775 principles.
• Appliance installation: correct appliance selection, siting, combustion air supply, ventilation and flue products exhaust, and commissioning requirements.
• Appliance rooms and boiler rooms: basic and specific location considerations (ventilation, fire protection, contamination and safe access).
• Competence of operatives: qualifications, knowledge areas (manufacturer instructions, national regulations, ventilation and flue design), and recommendations for mutual recognition across Member States.
• Inspection and maintenance: inspection definitions, preventative maintenance, corrective works and reporting requirements to confirm safety and conformity.
• Special cases: single‑appliance LPG installations using flexible connectors and compatibility/connection considerations.

Applications

CEN/TR 16940:2016 is practical guidance for professionals and stakeholders involved in domestic gas safety, including:

• Gas installers and heating engineers - for safe installation, commissioning and compliance checks.
• Designers and heating system specifiers - for appliance room layout, ventilation and flue design.
• Inspection and maintenance operatives - for inspection regimes, testing and reporting.
• Training bodies and certification schemes - for developing competence frameworks and mutual recognition matrices.
• Regulators, building owners and facility managers - for understanding recommended best practice for domestic gas safety.

Keywords: domestic gas installations, gas safety, pipework, appliance installation, flue exhaust, combustion air, inspection and maintenance, competence of operatives, CEN/TR 16940:2016.

Related Standards

• EN 1775 (principles for gas supply systems / pipework)
• CEN/TR 1749 (classification of gas appliances by combustion product evacuation)
• EN 437 (appliance gas categories)
• Gas Appliances Directive (CE marking and appliance conformity)

Standards Content (Sample)

SLOVENSKI STANDARD
01-junij-2017
*RVSRGLQMVNHSOLQVNHQDSHOMDYH3ULSRURþLOD]DYDUQRVW
Domestic gas installations - Recommendations for safety
Sicherheit von häuslichen Gasinstallationen - Empfehlungen
Installations intérieures de gaz - Recommandations pour la sécurité
Ta slovenski standard je istoveten z: CEN/TR 16940:2016
ICS:
13.120 Varnost na domu Domestic safety
91.140.40 Sistemi za oskrbo s plinom Gas supply systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN/TR 16940
TECHNICAL REPORT
RAPPORT TECHNIQUE
December 2016
TECHNISCHER BERICHT
ICS 91.140.40
English Version
Domestic gas installations - Recommendations for safety
Installations intérieures de gaz - Recommandations Gas Installationen in Haushalten - Empfehlungen für
pour la sécurité die Sicherheit

This Technical Report was approved by CEN on 18 January 2016.

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, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATIO N

EUROPÄISCHES KOMITEE FÜR NORMUN G

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 16940:2016 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Assuring the quality of installation and service work . 6
5 General technical requirements for pipework . 6
6 Technical requirements for appliance installations . 7
6.1 General . 7
6.2 Competence of operatives . 7
6.3 Selection of components and equipment . 8
6.4 Standards applying to appliance rooms . 8
6.5 Appliance commissioning . 11
7 Inspection and maintenance of installations and appliances . 12
7.1 General requirements . 12
7.2 Requirements for operatives . 12
8 Competence of operatives . 13
8.1 General . 13
8.2 Requirements to be competent . 14
8.3 DIY (Do It Yourself) activity . 15
8.4 Recommendations . 15
Annex A (informative) Coherence between types of gas appliances and ventilation/flue
products exhausts . 17
A.1 General . 17
A.2 Type A appliances . 17
A.3 Type B appliances . 17
A.4 Type C appliances . 18
Bibliography . 19
European foreword
This document (CEN/TR 16940:2016) has been prepared by CEN/SFG_I/SFG_U JWG “Safety of domestic
gas installations”, the secretariat of which is held by AFNOR/BNG.
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.
Introduction
As a result of the liberalization of the gas and services market in Europe and the need to reduce
potential barriers to trade, the development of mutually recognized standards covering design,
installation, inspection and maintenance of pipework and appliances downstream of the point of
delivery, including the development of a competence assessment scheme for gas operatives and
companies engaged in this sector is considered important.
The quality and safety of the gas installations are generally ensured through competent operatives,
installers and inspectors complying with technical regulations, inspection and maintenance regimes,
safety inspection of work .
To assist and facilitate the movement of operatives between states, a mutual recognition
framework/matrix that is agreed by all Member States can be envisaged. This should be designed and
developed to help Member States and those operatives wishing to relocate, to be able to benchmark
their respective knowledge, experience and qualifications against the requirements of the Host State. In
particular, the mutual recognition framework is described in the recommendations at the end of this
document.
1 Scope
This Technical Report gives recommendations to ensure the quality and safety of domestic gas
installations. This Technical Report covers pipe work, appliances installation, their combustion air
supply and flue products exhaust commissioning, inspection and maintenance activities carried out by
operatives.
This document addresses the following three main factors, which have an influence on gas safety in
general:
a) quality and safety of components of gas installations and gas appliances,
b) quality of the work when gas installations are constructed and commissioned,
c) inspection and maintenance of installations and gas appliances.
Potential ways in which individual competence of operatives and/or businesses can be ensured and
mutually recognized between Member States are considered.
The means of assuring responsible behaviour of consumers is not covered in this document.
It does not address metering or non-domestic (industrial and commercial) installations.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
CEN/TR 1749, European scheme for the classification of gas appliances according to the method of
evacuation of the combustion products (types)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
(From CEN Guide 14)
(From Marcogaz National Competency Framework)
3.1
inspection
checking or testing of an installation, by duly competent operatives, against established parameters
(which may relate to emission limits), its performance and its conformance to safety requirements
(checking the actual condition against a target condition), followed by the supply of a written report
confirming either compliance with all test parameters or detailing identified deficiencies (where these
are deemed so significant as to warrant such action)
3.2
maintenance
performance of preventative examinations, checks, cleaning, adjustment and repairs necessary to
maintain target conditions, and the remedying of deficiencies identified during inspection by duly
competent operatives, re-establishing target conditions as necessary
4 Assuring the quality of installation and service work
Domestic gas installations offer safe, efficient and user-friendly comfort to end-users provided they are
designed and installed by competent operatives, together with adequate maintenance and regular
inspection.
The competencies needed are given in 7.2; how to assess them in dealt with is given in 8.1 and 8.2.
In order to ensure quality and safety of gas installations, the following elements shall be considered:
— technical requirements for pipe work;
— technical requirements for appliance installations, including combustion air supply, ventilation and
flue products exhaust;
— prescriptions for inspection and maintenance of installations and appliances;
— if applicable, prescriptions for third party safety inspection of new and existing installations;
NOTE Safety inspection will often be incorporated into a maintenance specification, but may be offered
as a separate service, which can be compulsory, in the interests of assuring adequate safety performance of
an appliance/installation at an economic cost.
— assuring competence of operatives.
There is considerable variation, across Member States, with regards to the manner in which these
elements are provided for. Each of these elements are considered, in order to provide a basis for a
European best practice for minimum safety requirements.
Technical standards may be complemented by more detailed national standards, which should be
applied in association with European Standards, but will not conflict with them. There may also be
additional requirements in national legislation / regulations, particularly those relating to the
construction of services within buildings, which shall take precedence.
5 General technical requirements for pipework
General technical requirements for pipework, so as to achieve a consistent basis for the safe and
efficient installation of gas pipework in domestic premises, are given in EN 1775.
EN 1775 covers principles of gas supply systems.
This functional standard specifies the common appropriate principles and the recognized practices
concerning:
— design;
It is emphasized that gas pipework shall be sized so that the pressure at the inlet of all gas
appliances is compatible with their safe and effective operation.
— installation and construction;
— testing;
— commissioning;
— operation and maintenance;
— working on operating pipe.
It shall be applied by competent persons who have suitable knowledge, experience and approval.
The standard is for pipework between the point of delivery of the gas and the inlet connection to the gas
appliances. It applies to new installation pipework and replacement of, or extensions to, existing
pipework. It does not cover buried pipework, gas metering systems, LPG storage vessels or single
appliance LPG installations without fixed pipework, achieved by a flexible appliance connector from an
adjacent LPG storage cylinder.
6 Technical requirements for appliance installations
6.1 General
This clause deals with the achievement of a consistent basis for the sustainable, safe and efficient
installation of gas appliances in domestic premises, whether in specific appliance rooms or other spaces
where gas appliances are installed, in relation to the requirements for:
a) design and installation;
b) correct appliance selection;
c) correct location;
d) combustion and ventilation air;
e) flue products exhaust;
f) correct commissioning;
g) correct maintenance.
It shall be applied by competent persons who have suitable knowledge, experience and approval.
The occupants and owners of domestic dwellings are responsible for the installation during its
operation. They shall be provided with written information about the functioning, maintenance and
safety of the appliances.
Single appliance LPG installations without fixed pipework, achieved by a flexible appliance connector
from an adjacent LPG storage cylinder are also considered in this document.
6.2 Competence of operatives
The general requirements for competence are dealt with in 8.1.
The design of the boiler room, or any other space the appliances are placed in, will usually be the
responsibility of a structural engineer or heating design company in new build or refurbishment
projects. However, on one-off domestic installations, this responsibility for design will lie with the
installer / installation company.
To ensure the safe functioning of the appliances, the safety of occupants or operatives, efficiency and
the environmental considerations, the designer/operative shall have sufficient education and/or
proven knowledge in the following areas:
a) the selection of an appropriate appliance type;
b) the national installation regulation;
c) the applicable standards (European or national);
d) the application of manufacturer’s installation/operating instructions;
e) the calculation of ventilation requirements;
f) the design of flue duct / chimney size, route, materials, etc.;
g) the design of flue termination for effective and safe performance;
h) the design of condensate drainage systems, when applicable.
6.3 Selection of components and equipment
New appliances to be installed in domestic dwellings have to be in compliance with the Gas Appliances
Directive and have to be CE marked with an appliance category allowed in the Member state in which
they are installed. Since there are different gas qualities delivered to domestic users in the European
community, it is of importance that the designer / operative is aware of the range of gas quality on site.
Previously used (i.e. second-hand, previously owned or customers own) or modified appliances can be
found not being CE marked and so particular care needs to be taken to ensure both their fitness for
purpose and their compatibility with the supplied gas. Therefore, it is essential that a suitable appliance
and, as appropriate, the components of the gas installation match the gas quality on site. As gas quality
may change over time, adjustment to the quality of the gas supplied on the day of commissioning can
result in unsafe conditions when gas quality varies afterwards. Settings shall be able to accommodate
the range corresponding to the appliance category (see EN 437) declared by the manufacturer.
The designer/operative shall take into account the national safety regulations especially those
regarding the connection of gas appliances through a flexible appliance connector or a length of rigid
pipe work, the compatibility of connectors and the use, when necessary, of a safety shut off device.
A manually operated valve or equivalent mean shall be installed on the fixed pipework in the immediate
vicinity of each appliance in order to allow a quick shut off of the gas flow to the appliance or, if
applicable and allowed, group of appliances in case of emergency.
Where an en fitting is designed to permit quick connection and disconnection of the flexible appliance
connector, this fitting shall be self-sealing and shall prevent the release of gas from the upstream
pipework. This fitting shall be designed to prevent accidental disconnection and incorrect assembly.
6.4 Requirements applying to appliance rooms
6.4.1 General
As far as known at the time or writing, there are no European Standards on appliance rooms. Therefore,
these rooms shall be in compliance with national regulations/standards and appliance manufacturers'
instructions. General principles of coherence are described in Annex A.
6.4.2 Basic conditions
As the functioning of gas appliances may be affected by the construction of the room or space in which
the appliance is installed, it is essential that the operative checks that the flue, ventilation and location
requirements meet manufacturer’s instructions and any national safety regulations.
When selecting gas appliances, coherence shall be ensured between the type of appliance regarding the
evacuation of combustion products (see CEN/TR 1749), the type of appliance room and its ventilation.
The rules of installation and the rules for supply of combustion air, ventilation and for fire protection
are defined in the national safety regulations.
6.4.3 Specific location requirements
6.4.3.1 Boiler rooms
Boiler rooms shall meet specific appliance manufacturer’s requirements and national legislation (e.g.
Occupational Health and Safety, Building, Factory and Labour Law) may be applicable. The following
should also be taken into account:
— fire protection and precautions,
— contamination of combustion air,
— persons coming into contact with hot surfaces,
— the removal of any flue gas leakages or other dangerous gases and/or vapours which can occur in
the appliance room.
6.4.3.2 Cooking and washing appliance rooms
Installation of cooking and washing appliances can only be made in sufficiently ventilated rooms
according to national or local codes.
Ventilation shall be able to supply appliances with enough combustion air according to manufacturer’s
instructions and to evacuate flue products in order to prevent in the room or space concerned, a
concentration of substances harmful to health likely to present a danger.
Such appliances shall not be installed in living rooms as sleeping rooms, bathrooms or dining rooms
separate from kitchens.
It is supposed for the application of the present document that all gas appliances installed to be used
indoor are equipped with a flame safety device (or an equivalent system). Unfortunately, many gas
domestic cooking appliances still exist which are not equipped with such a device on all the burners. In
that case, the ventilation system shall be designed in order to avoid an accumulation of unburned gases,
according to national regulations.
6.4.3.3 Other type A appliance rooms
For health and safety reasons, it is not recommended to install and use type A appliances other than
cooking and washing appliances inside domestic dwellings. Consequently, it may be only done if
allowed by and according to national or local codes and in addition according to the appliance
manufacturer’s instructions.
6.4.4 Flue exhaust systems
6.4.4.1 General
Where appliances are connected to a flue, the effective operation of the appliance depends on the
quality of the flue system design and construction. It is essential that the operative is aware of the
possibility of condensation of flue gases and knowledge of the dew point of flue gases, together with the
consequential effects. Awareness of the differing requirements for the different classification of flue
types under CEN/TR 1749 is necessary.
The operative shall consider the following aspects in relation to chimney/flue construction.
General flue systems requirements include:
— robustness of construction,
— suitability of materials of construction,
— fire protection of building,
— tightness to flue gases and/or condensed water,
— facilities/system for draining condensed water,
— specific appliance and chimney manufacturer’s requirements.
In addition, the operative shall understand the differing design and performance characteristics of the
various flue/chimney types utilized in connection with gas appliances taking into account draught
conditions required by the appliance manufacturer.
6.4.4.2 Chimney requirements
Chimneys can be of various types:
— natural draught chimney as individual flue system;
— natural draught chimney as common flue system;
— fan assisted chimney (negative pressure) as common flue system with a fan mounted atop the
chimney;
— forced draught chimney as individual flue system;
— forced draught chimney as individual flue system designed to operate at a positive pressure (e.g.
with a resistance to condensed water in case of condensing appliances).
The European Standards relating to chimneys are EN 1443, EN 1856 (all parts) and EN 13384 (all
parts).
The connection of the appliance with the chimney shall be made with an appropriate duct (material,
size, tightness, slope) in compliance with applicable regulations and standards.
6.4.4.3 Other systems requirements
These systems can be:
— individual duct system supplying combustion air and flue gases with flue gases at a negative
pressure;
— individual duct system supplying combustion air and flue gases with flue gases at a positive
pressure;
— common duct system supplying combustion air and flue gases with flue gases at a negative
pressure;
— common duct system supplying combustion air and flue gases with flue gases at a positive pressure.
Flue ducts shall be designed and installed so as to avoid any dangerous release of combustion products
into habitatable rooms. Particular attention should be paid to the following possible situations:
— leakages from flue systems operating at positive pressure;
— com
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