Refrigerating systems and heat pumps - Liquid level indicating devices - Requirements, testing and marking

This European standard describes requirements and tests for liquid level indicating devices used in refrigerating systems and heat pumps. It applies to devices connected to refrigerant vessels (e.g. on high-pressure liquid receivers, intercoolers and low-pressure separators) and to devices connected to other parts of a refrigerating system (e.g. oil-level sight glasses on a compressor).

Kälteanlagen und Wärmepumpen - Flüssigkeitsstandanzeiger - Anforderungen, Prüfung und Kennzeichnung

Systèmes de réfrigération et pompes à chaleur - Indicateurs de liquide - Exigences, essais et marquage

La présente Norme européenne spécifie les exigences de sécurité, les coefficients de sécurité, les méthodes d’essai, les pressions d’essai utilisées ainsi que le marquage des appareils indicateurs de niveau de liquide, ci-après désignés par « indicateurs de niveau », destinés à être utilisés dans les systèmes de réfrigération et les pompes à chaleur.
Elle s’applique aux appareils reliés à des récipients de fluide frigorigène (par exemple réservoirs de liquide haute pression, sous-refroidisseurs et réservoirs basse pression) et aux appareils reliés à d’autres éléments d’un système de réfrigération (par exemple des voyants de niveau d’huile sur un compresseur).
La présente Norme européenne s’applique aux types d’indicateurs de niveau à lecture directe et indirecte (par exemple voyants, tubes de givrage) y compris les indicateurs électriques et pneumatiques.
La présente Norme européenne décrit la procédure à suivre lors de la conception (par calcul ou par une méthode expérimentale de conception) des éléments d’indicateur de niveau soumis à une pression, ainsi que les critères à appliquer lors de la sélection des matériaux.
La présente Norme européenne s’applique à la conception des indicateurs de niveau eu égard au confinement de la pression et décrit les méthodes permettant de prendre en compte en toute sécurité des valeurs de résilience faibles à basse température.
Elle fournit également des lignes directrices sur certains aspects de la mise en oeuvre et de l’installation.

Hladilni sistemi in toplotne črpalke - Naprave, ki označujejo nivo tekočine - Zahteve, preskušanje in označevanje

Ta evropski standard opisuje zahteve in preskuse za naprave, ki označujejo nivo tekočine v hladilnih sistemih in toplotnih črpalkah. Uporablja se za naprave, povezane s hladilnimi posodami (npr. na visokotlačnih zbiralnikih tekočine, hladilnikih in nizkotlačnih ločevalnikih), in naprave, povezane z drugimi deli hladilnega sistema (npr. odprtinah za preverjanje nivoja olja na kompresorju).

General Information

Status
Published
Public Enquiry End Date
04-Jun-2016
Publication Date
04-Dec-2016
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
02-Dec-2016
Due Date
06-Feb-2017
Completion Date
05-Dec-2016

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Kälteanlagen und Wärmepumpen - Flüssigkeitsstandanzeiger - Anforderungen, Prüfung und KennzeichnungSystèmes de réfrigération et pompes à chaleur - Indicateurs de liquide - Exigences, essais et marquageRefrigerating systems and heat pumps - Liquid level indicating devices - Requirements, testing and marking27.200Hladilna tehnologijaRefrigerating technology27.080Heat pumpsICS:Ta slovenski standard je istoveten z:EN 12178:2016SIST EN 12178:2017en,fr,de01-januar-2017SIST EN 12178:2017SLOVENSKI

STANDARDSIST EN 12178:20041DGRPHãþD
SIST EN 12178:2017
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 12178
November
t r s x ICS
t yä r z râ
t yä t r r Supersedes EN
s t s y zã t r r uEnglish Version

Refrigerating systems and heat pumps æ Liquid level indicating devices æ Requirementsá testing and marking Systèmes de réfrigération et pompes à chaleur æ Indicateurs de liquide æ Exigencesá essais et marquage Kälteanlagen und Wärmepumpen æ Flüssigkeitsstandanzeiger æ Anforderungená Prüfung und Kennzeichnung This European Standard was approved by CEN on

z August
t r s xä

egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä

translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä

CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey andUnited Kingdomä

EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels

t r s x CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN

s t s y zã t r s x ESIST EN 12178:2017
EN 12178:2016 (E) 2

Contents Page European foreword ................................................................................................................................................................ 4 1 Scope ............................................................................................................................................................................. 5 2 Normative references ............................................................................................................................................. 5 3 Terms and definitions ............................................................................................................................................ 5 4 List of Symbols ........................................................................................................................................................... 7 5 General requirements ............................................................................................................................................ 7 5.1 Installation and operation .................................................................................................................................... 7 5.2 Components under pressure ............................................................................................................................... 8 5.3 Excessive mechanical stress ................................................................................................................................. 8 5.4 Leakage ........................................................................................................................................................................ 8 6 Materials ...................................................................................................................................................................... 8 6.1 Material properties ................................................................................................................................................. 8 6.2 New materials ............................................................................................................................................................ 8 6.3 Using non-metallic materials ............................................................................................................................... 8 6.4 Requirements for materials to be used for pressurized parts ................................................................ 8 6.5 Compatibility of connections ............................................................................................................................... 8 6.6 Ductility ....................................................................................................................................................................... 8 6.7 Brittle fracture .......................................................................................................................................................... 8 6.8 Ageing ........................................................................................................................................................................... 8 6.9 Castings ........................................................................................................................................................................ 9 6.10 Forged and welded components ......................................................................................................................... 9 6.11 Nuts, bolts and screws ............................................................................................................................................ 9 6.12 Glass materials .......................................................................................................................................................... 9 6.13 Gasket materials ....................................................................................................................................................... 9 7 Design ........................................................................................................................................................................... 9 7.1 General ......................................................................................................................................................................... 9 7.2 Requirements for glass .......................................................................................................................................... 9 7.3 Surface requirements .......................................................................................................................................... 11 7.4 Corrosion protection............................................................................................................................................ 11 7.5 Inner cleanness ...................................................................................................................................................... 11 8 Fitting requirements ............................................................................................................................................ 11 9 Testing ....................................................................................................................................................................... 12 10 Application .............................................................................................................................................................. 12 10.1 Liquid hammer ....................................................................................................................................................... 12 10.2 Frosting tubes ......................................................................................................................................................... 12 10.3 Liquid level indicators with magnetically operated indication ........................................................... 12 10.4 Maximum and minimum liquid level ............................................................................................................. 12 11 Marking and additional information ............................................................................................................. 12 11.1 General ...................................................................................................................................................................... 12 11.2 Marking ..................................................................................................................................................................... 13 11.3 Level indicators of nominal size DN 25 and smaller ................................................................................ 13 12 Documentation ....................................................................................................................................................... 13 12.1 Documentation for level indicators ................................................................................................................ 13 SIST EN 12178:2017

EN 12178:2016 (E)

3 12.2 Documentation for level indicators of nominal size DN 25 and smaller ........................................... 14 Annex ZA (informative)

Relationship between this European Standard and the essential requirements of EU Directive 2014/68 EU of the European Parliament and of the Council of 15 May 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of pressure equipment aimed to be covered............................... 15 Bibliography .......................................................................................................................................................................... 16

SIST EN 12178:2017
EN 12178:2016 (E) 4

European foreword This document (EN 12178:2016) has been prepared by CEN/TC 182, “Refrigerating systems, safety and environmental requirements”, 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 May 2017, and conflicting national standards shall be withdrawn at the latest by May 2017. 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 12178:2003. EN 12178:2016 includes the following significant technical changes with respect to EN 12178:2003: a) Introduction of the safety factors in 7.2.1; b) Harmonisation of Annex ZA with Directive 2014/68/EU. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s). For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this document. 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, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 12178:2017

EN 12178:2016 (E)

5 1 Scope This European Standard specifies safety requirements, safety factors, test methods, test pressures and marking of liquid level indicating devices, referred to throughout this standard as “level indicators”, for use in refrigerating systems and heat pumps. It applies to devices connected to refrigerant vessels (e.g. on high-pressure liquid receivers, intercoolers and low-pressure receivers) and to devices connected to other parts of a refrigerating system (e.g. oil-level sight glasses on a compressor). This European Standard applies to those types of level indicators that are direct and indirect reading devices (e.g. sight glasses, frosting tubes), and includes electrical and pneumatic indicators. This European Standard describes the procedure to be followed when designing (by calculation or by an experimental design method) level indicator parts subjected to pressure as well as the criteria to be used for the selection of materials. This European Standard applies to the design of level indicators with respect to pressure containment and describes methods by which the reduced impact values at lower temperatures may be taken into account in a safe manner. It also gives guidance on some aspects of application and installation. 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. EN 378-1, Refrigerating systems and heat pumps — Safety and environmental requirements — Part 1: Basic requirements, definitions, classification and selection criteria EN 378-2, Refrigerating systems and heat pumps — Safety and environmental requirements — Part 2: Design, construction, testing, marking and documentation EN 378-4, Refrigerating systems and heat pumps — Safety and environmental requirements — Part 4: Operation, maintenance, repair and recovery EN 764-1, Pressure equipment — Part 1: Vocabulary EN 12284:2003, Refrigerating systems and heat pumps — Valves — Requirements, testing and marking EN 60529, Degrees of protection provided by enclosures (IP Code) (IEC 60529) 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 378-1 and EN 764-1 and the following apply. 3.1 min t0 100 lowest temperature at which pressurized parts can be used at a load of up to 100 % of the allowable design stress at 20 °C, taking the safety factors according to EN 12284:2003, Table A.2 into account SIST EN 12178:2017

EN 12178:2016 (E) 6

3.2 min t0 75 lowest temperature at which pressurized parts can be used, if its load amounts to 75 % maximum of the allowable design stress at 20 °C, taking the safety factors according to EN 12284:2003, Table A.2 into account 3.3 min t0 25 lowest temperature at which pressurized parts can be used, if their load amounts to 25 % maximum of the allowable design stress at 20 °C, taking the safety factors according to EN 12284:2003, Table A.2 into account 3.4 self-closing balls self-closing shut-off arrangement Note 1 to entry: The arrangement comprises balls positioned in the connecting channel close to the sight glass in such a manner that the balls will not be affected at low flow rates. At high flow rates the balls will be carried forward with the flow and block the connections to the sight glass. 3.5 reflex glass glasses having prismatic flutes on the inside, which will break up the incoming light Note 1 to entry: The liquid zone will absorb the light and will correspondingly appear dark. The gas/vapour zone will reflect the light and will correspondingly appear bright. 3.6 direct reading level indicator level indicator where it is possible to see the liquid level 3.7 indirect reading level indicator level indicator where the liquid level is not visible Note 1 to entry: The level is indicated by auxiliary means; electrically, magnetically or by observing the frost on a tube. 3.8 self-contained unit level indicator which is assembled and tested by the manufacturer 3.9 add-on unit level indicator delivered in parts from the manufacturer for mounting directly onto the system and which can only be tested after assembly and connection on site 3.10 level indicator with m

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