vaccum tube

1.material of borosilicate glass 3.3, thickness 1.6mm
2.bsorptive coating graded AL-N/AL, Vacuum<5*10-3Pa
3.absorptance>92%(Am1.5), emittance<8%(80&#8451;)
4.thermal expansion 3.3*10-6&#8451;, stagnation temperature>200&#8451;
5.heat loss<0.8w/sqm maximum strength 0.8Mpa
6.outer tube diameter 47mm,inner tube diameter 37mm,with length 1500mm
7.outer tube diameter 58mm,inner tube diameter 47mm,with length 1800mm/2000mm/2100mm
8.outer tube diameter 70mm,inner tube diameter 58mm,with length 2000mm/2100mm