In the semiconductor industry, large diameter fused quartz tubes are widely used as materials of furnace chambers for processing silicon wafers due to their high purity and excellent heat resistance.  Valiant offers two methods to produce these large diameter tubes: electrically fusion and flame fusion. 

QL110LD:   is the series of large diameter tubes with all properties similar to QL110, which is made by electrically fusion.  A full range of diameters, up to 300mm, is available in Valiant These low cost tubes offer the level of purity, furnace life, processing temperature and other properties that semiconductor industry requires.

QL510:  is the series of large diameter tubes made by flame fusion.   Valiant successfully extends the diameter upto 500mm.  The supplying of flame fused tubes is much more flexible than QL110LD type.  No minimum order quantity and short leadtime is the advantage of QL510 type. 

Special heavy wall thicknesses used as bell jar sleeves are also available upon requests.