Heating tube collector

Feature:
A. Water wouldn't run in the tube,so the heat delivery efficiency wouldn't be affected.
B. Both for pressurized and non-pressurized one.
C. The whole system would run normally if some of vacuum tubes broke.
D. The whole system is connected without silica gel, so there is no problem of aging.
E. The water is circulated with high efficiency by pumper.
F. It can be for huge project by parallel or serial connection.