Prelco
1-800-463-1325

Heat-Soaked Test

Prel-Gard HST

Test thermique secondaire

Prel-Gard Heat Soak Test - HS:

  • Heat soaked glass, HST, is tempered glass that is heated with the aim of eliminating any glass that is subject to spontaneous breakage, before installation.  
  • The HST test identifies batches of glass which have a high incidence of nickel sulfide inclusions, a contaminant responsible for spontaneous breakage. 
  • Suitable for tempered glass before it is installed in difficult to access places, high elevations or locations that require extra protection, for instance structural glass building facades.
  • Spontaneous breakage of tempered glass installed at high elevations could cause injury and in addition generate high replacement costs.  HST reduces to a minimum security and financial risks.

Characteristics

  • The HST treatment consists in heating the glass to a temperature of about 290°C for a given period of time and then allowing it to cool slowly.  
  • This treatment, done in the factory before installation, causes the nickel sulfide inclusions to expand and spontaneous breakage to occur.  
  • During the manufacturing process, nickel sulfide inclusions are mixed into the batch material before being dissolved.  Measuring 3 to 15 mils in diameter, these inclusions are difficult to detect with the naked eye.
  • These inclusions, when located near the centre of the glass, may expand and produce sufficient stress to cause spontaneous breakage of the tempered glass.

Applications

  • Structural glass, skylights, atriums
  • High value-added sealed units
  • Glass located in hard to reach locations

Production Capacity

Thickness

Minimum Dimensions

Maximum Dimensions*

Weight

Size Tolerances

mm

in

mm

in

mm

in

kg/m2

lb/pi2

mm

in

3

1/8

102 x 229

4 x 9

1499 x 2286 59 x 90

7.86

1.61

±1.6

±1/16

4

5/32

102 x 229

4 x 9

1778 x 2794 70 x 110

9.91

2.03

±1.6

±1/16

5

3/16

102 x 229

4 x 9

2286 x 3810

90 x 150

11.96

2.45

±1.6

±1/16

6

1/4

102 x 229

4 x 9

2794 x 5182 110 x 204

14.60

2.99

±1.6

±1/16

8

5/16

102 x 229

4 x 9

2794 x 5182 110 x 204

20.02

4.10

±2.0

±5/64

10

3/8

102 x 229

4 x 9

2794 x 5182 110 x 204

23.97

4.91

±2.4

±3/32

12

1/2

102 x 229

4 x 9

2794 x 5182 110 x 204

31.54

6.46

±3.2

±1/8

15

5/8

102 x 229

4 x 9

2438 x 4978 96 x 196

39.40

8.07

±4.0

±5/32

19

3/4

102 x 229

4 x 9

2438 x 4978 96 x 196

47.31

9.69

±4.8

±3/16

  *Certain conditions apply, contact-us for further information.

Projects

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Collège BrébeufStructural Point Supported Glass and Heat-Soaked Test

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Documentation to download

Green Buildings
Thermaspec : Performance Calculating Tool
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