... solar vacuum tube & pyrex glass tubes3.3 with best quality 1.size: OD 3MM-315MM 2.Light ... with best quality size: from 3-315mm, and the tubes of 37, 47, 58, 70 for the solar water heater.the high ... -proof, anti-rot, mechanical capacity, high working temperature, good technical quality and the favourable price.Main composition:1 ... 3±0.1 (10-6K-1)2) Transformation temperature: 525±15°C3) Working point: 1,260 ...