Bsi bs en 14178 1 2004

Unknown BRITISH STANDARD BS EN 14178 1 2004 Glass in building — Basic alkaline earth silicate glass products — Part 1 Float glass The European Standard EN 14178 1 2004 has the status of a British Stan[.]

Glass in building —

Basic alkaline earth

silicate glass

products —

Part 1: Float glass

The European Standard EN 14178-1:2004 has the status of a

British Standard

ICS 81.040.20

This British Standard was

published under the authority

of the Standards Policy and

Strategy Committee on

20 October 2004

© BSI 20 October 2004

National foreword

This British Standard is the official English language version of

EN 14178-1:2004

The UK participation in its preparation was entrusted by Technical Committee B/520, Glass and glazing in building, to Subcommittee B/520/1, Glass and glazing in building — Basic and transformed glass products, which has the responsibility to:

A list of organizations represented on this subcommittee can be obtained on request to its secretary

Cross-references

The British Standards which implement international or European

publications referred to in this document may be found in the BSI Catalogue

under the section entitled “International Standards Correspondence Index”, or

by using the “Search” facility of the BSI Electronic Catalogue or of British

Standards Online

This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application

Compliance with a British Standard does not of itself confer immunity from legal obligations.

— aid enquirers to understand the text;

— present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the

UK interests informed;

— monitor related international and European developments and promulgate them in the UK

Summary of pages

This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 17 and a back cover

The BSI copyright notice displayed in this document indicates when the document was last issued

Amendments issued since publication

NORME EUROPÉENNE

ICS 81.040.20

English version

Glass in building Basic alkaline earth silicate glass products

-Part 1: Float glass

Verre dans la construction - Verre de silicate alcalinoterreux

de base - Partie 1: Glace flottée Glas im Bauwesen - Basiserzeugnisse aus Erdalkali-Silicatglas - Teil 1: Floatglas

This European Standard was approved by CEN on 27 May 2004.

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 Central Secretariat 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 Central Secretariat has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION

C O M I T É E U R O P É E N D E N O R M A L I S A T I O N

E U R O P Ä IS C H E S K O M IT E E FÜ R N O R M U N G

Management Centre: rue de Stassart, 36 B-1050 Brussels

© 2004 CEN All rights of exploitation in any form and by any means reserved

worldwide for CEN national Members. Ref No EN 14178-1:2004: E

Contents Page

Foreword 3

1 Scope 4

2 Normative references 4

3 Terms and definitions 4

4 Chemical composition 5

4.1 Principal constituents 5

4.2 Tint 6

5 Physical and mechanical characteristics 6

5.1 General characteristics 6

5.2 Designation of clear alkaline earth silicate glass 7

5.3 Stability of physical and chemical characteristics 8

6 Dimensional requirements 8

6.1 Thickness 8

6.1.1 Tolerances 8

6.2 Manufacturing dimensions 8

6.3 Length, width, and squareness 8

7 Quality Requirements 9

7.1 Methods of observation and measurement 10

7.1.1 Optical faults 10

7.1.2 Visual faults 11

7.2 Acceptance levels 11

7.2.1 Optical faults 11

7.2.2 Spot faults 12

7.2.3 Linear / extended faults 13

7.2.4 Edge defects for final cut sizes 14

8 Designation 15

Bibliography 17

Foreword

This document (EN 14178-1:2004) has been prepared by Technical Committee CEN/TC TC 129 “Glass in building”, the secretariat of which is held by IBN

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 April 2005, and conflicting national standards shall be withdrawn at the latest by April 2005

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, B, C or D, which is an integral part of this document can be found in EN 14178-2

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom

1 Scope

This document defines and classifies basic alkaline earth silicate glasses for use in building It indicates their chemical composition, main physical and mechanical properties, dimensional and minimum quality requirements (in respect of optical and visual faults)

This document applies to basic alkaline earth silicate glasses supplied in jumbo sizes, split sizes and final cut sizes

This document does not apply to final cut sizes having a dimension less than 100mm or a surface area less than 0,05m²

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

EN 410, Glass in building — Determination of luminous and solar characteristics of glazing

3 Terms and definitions

For the purposes of this document, the following terms and definitions apply

3.1

basic alkaline earth silicate glass

flat, transparent, clear or tinted float glass with a chemical composition according to 4.1 of this document, having parallel and polished faces obtained by continuous casting and floatation on a metal bath

3.2

length, H, and width, B

these are defined with reference to the direction of draw of the float glass ribbon as shown in Figure 1

Figure 1 — Relationship between length, width and direction of draw 3.3

jumbo sizes

glass delivered in the following sizes:

Nominal length H: 4500 mm, 5100 mm or 6000 mm

Nominal width B: 3210 mm

NOTE The usual width is 3210 mm Exceptional production requirements may cause this to be reduced but the nominal width is never below 3150 mm

3.4

split sizes

glass delivered in the following size ranges:

Nominal length H: 1000 mm to 2550 mm

Nominal width B: 3210 mm

NOTE The usual width is 3210 mm Exceptional production requirements may cause this to be reduced but the nominal width is never below 3150 mm

3.5

final cut size

pane of glass that has been cut down to the dimensions being required either for installation or processing into

a final product e.g insulating glass units, thermally toughened safety glass, …of those dimensions

3.6

optical faults

these are faults that lead to distortions in the appearance of objects observed trough the glass

3.7

visual faults

faults, which alter the visual quality of the glass They are spot faults and linear / extend faults

3.8

spot faults

a spot fault is a nucleus, which is sometimes accompanied by a halo of distorted glass The dimension of a spot fault comprising a nucleus with a halo is obtained by multiplying the dimension of the nucleus by a factor

of approximately 3

3.9

linear / extended faults

these faults can be on or in the glass, in the form of deposits, marks or scratches that occupy an extended length or area

3.10

edge defects

these defects can occur on the edge of a cut size piece in the form of entrant and emergent faults and / or bevels

4.1 Principal constituents

The magnitude of the proportions by mass of the principal constituents of all the alkaline earth silicate glass products covered by this document is as follows:

Potassium Oxide K2O 5- 14%

4.2 Tint

Body tinted glass is obtained by the addition of suitable materials

5 Physical and mechanical characteristics

5.1 General characteristics

Conventional numerical values for the physical and mechanical characteristics of basic alkaline earth silicate glass products are given in Table 1 These values, for normal annealed glass without any further toughening, are not precise requirements with which the glass shall strictly comply, but are the generally accepted figures for use in calculations where a high degree of accuracy is not required

Table 1 — General characteristic values of alkaline earth silicate glass

Young's modulus (modulus of

Characteristic bending strength f g,k k 45 x 106 Pa [1]

Nominal value of average coefficient

of linear expansion between 20 oC

Resistance against temperature

differential and sudden temperature

[2]

Mean refractive index to visible

Corrected emissivity ε 0,837

[1] The characteristic bending strength has to be used in conjunction with the design method given in prEN 13474

[2] Generally accepted value that is influenced by edge quality and glass type

5.2 Designation of clear alkaline earth silicate glass

An earth alkaline silicate glass product is defined as clear alkaline earth silicate glass when it is not tinted and when the light transmittance of the glass material, unmodified by the possible presence of a coating:

- after any necessary pre-treatment

- measured according to EN 410

- rounded to the nearest 0,01

is greater than or equal to the value given in Table 2 for the nominal thickness of the alkaline earth silicate glass product

In order to measure the light transmittance characteristics of alkaline earth silicate glass, to determine whether

it can be classified as clear, it is necessary, in some cases, to carry out a pre-treatment:

- coatings on smooth surfaces have to be eliminated, without modifying the thickness of the alkaline earth silicate glass substrate

The light transmittance of an alkaline earth silicate glass substrate has to be measured with its surfaces in a polished condition

Table 2 — Mean values for determining if a transparent alkaline earth silicate glass product is clear

2

3

4

5

6

8

10

12

15

0,90 0,90 0,90 0,89 0,89 0,88 0,87 0,86 0,84

1) The limiting values given are applicable provided that the measured thickness of the alkaline earth silicate glass product is within the allowable tolerances for the nominal thickness of that product

2) The values given are not suitable for design They are values used only for the definition of clear alkaline earth silicate glass and exclude the effects of coatings The values of light transmittance used for design should be obtained from the glass manufacturer, measured according to EN 410

5.3 Stability of physical and chemical characteristics

For alkaline earth silicate glass products, the physical and chemical characteristics can be considered as remaining constant over time

a) Since glass is insensitive to photochemical effects, the spectral properties (transmissions of light and solar energy) of the basic earth alkaline silicate glass products are not modified by direct or indirect solar radiation

b) The surface of glass used in building is virtually insensitive to attack from the environment

NOTE: Whilst the surface of the glass when installed in a building is virtually insensitive to attack from water care should be taken to protect the glass surface prior to installation Inappropriate storage can result in water/humidity being drawn up between glass sheets This concentrated environment can cause attack of the surface (see [1])

6.1 Thickness

The actual thickness shall be the average of four measurements, taken to the nearest 0,01 mm, one taken at the centre of each side Measurement shall be made by means of an instrument of the caliper micrometer type

6.1.1 Tolerances

The actual thickness, rounded to the nearest 0,1 mm shall not vary from the nominal thickness by more than the tolerances shown in Table 3

Table 3 — Tolerances on nominal thickness

Dimensions in mm

2

3

4

5

6

8

10

12

15

± 0,2

± 0,2

± 0,2

± 0,2

± 0,2

± 0,3

± 0,3

± 0,3

± 0,5

6.2 Manufacturing dimensions

6.3 Length, width, and squareness

The nominal dimensions for the length, H, and width, B, being given the pane shall not be larger than a prescribed rectangle resulting from the nominal dimensions increased by the permissible plus tolerance, t, or smaller than a prescribed rectangle resulting from the nominal dimensions reduced by the permissible minus

tolerance, t The sides of the prescribed rectangles shall be parallel to one another and these rectangles shall have a common centre (see Figure 2)

The limits of squareness shall also be prescribed by these rectangles

Figure 2 — Determination of length, width and squareness

The tolerance, t, on the nominal dimensions length H and width B is given in Table 4

Table 4 — Tolerance on the nominal dimensions length and width

Dimensions in mm Tolerance t [mm]

Final cut sizes Thickness

Jumbo / split

(H, B) ≤ 1500 1500 < (H,B) ≤ 3000 (H, B) > 3000

One quality level is considered in this document This is determined by evaluation of the optical and visual faults

Optical faults are determined on the dimensions of glass as manufactured, i.e jumbo or split size Visual faults can be checked for all dimensions, i.e jumbo, split or final cut sizes, with the level of acceptance being related

to the dimensions

Note: The manufacturer(s) should be consulted if higher levels of quality are required

7.1 Methods of observation and measurement

7.1.1 Optical faults

A screen bearing an assembly of black and white stripes (zebra) is observed through the glass to be examined

The usual size of screen is between 1500 mm x 1150 mm and 2500 mm x 2000 mm It consists of a translucent white background with parallel black stripes, 25 mm wide and 25 mm apart, inclined at 45°

The screen is uniformly lit from behind with white daylight fluorescent tubes The illuminance of the screen measured 1m from it should be between 400 and 1200 lux The walls of the test room should be painted with

a dark non-reflective paint having a diffuse reflection ≤ 0,10

The glass to be examined shall be held vertically in a support frame The centre of the glass shall be at a distance of 4,5 m from the screen and on a line normal to the centre of the screen The glass shall be capable

of being rotated around a vertical axis The glass shall be held with the direction of draw of the glass vertical Appropriate critical viewing angles, α, formed by the glass and the screen should be indicated (see Figure 3) The observer stands still at a distance of 9 m from the centre of the screen on a line passing through the axis

of rotation

Key

A Screen

B Glass sample

C Observer

Figure 3 — Plan view showing set-up of zebra test

The glass being examined is rotated from an angle α = 90° until there is no longer any distortion of the lines

on the screen The angle α (see fig 3) at which this occurred is noted

The glass sample taken for this examination shall have a length, H, of between 300 mm and 500 mm and a width, B, of approx 800 mm The distortion is measured in the areas d and D as shown in Figure 4