factory solar vacuum tube & pyrex glass tubes3.3 for sale 1.size: OD 3MM-315MM 2.Light,medium and heavy

factory solar vacuum tube & pyrex glass tubes3.3 for sale

size: from 3-315mm, and the tubes of 37, 47, 58, 70 for the solar water heater.

the high borosilicate glass tube enjoys good heat-proof, anti-rot, mechanical capacity, high working temperature, good technical quality and the favourable price.

Main composition:1) SiO2: 80±0.5%2) B2O3: 13±0.2%3) Al2O3: 2.4±0.2%4) Na2O(+K2O): 4.3±0.2%

Chemical properties:1) Coefficient of mean linear thermal expansion (20°C/300°C):3.3±0.1 (10-6K-1)2) Transformation temperature: 525±15°C3) Working point: 1,260±20°C4) Softening point: 820±10°C5) Density at 20°C: 2.23g/cm6) Hydrolytic resistance at 98°C: ISO719-HGB17) Hydrolytic resistance at 121°C: ISO720-HGA1

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factory solar vacuum tube & pyrex glass tubes3.3 for sales