iW Solar supplies the two vacuum tube families our collectors run on: the Φ58 × 1,800 mm all-glass twin tube and the Φ70 × 2,000 mm glass–metal heat pipe tube — both in high borosilicate glass 3.3, both anti-freezing and built for B2B volumes. Manufacturing in Taian City, Shandong Province, since 2013; OEM & ODM for importers and project contractors.
A solar vacuum tube is the engine of every evacuated-tube collector: two coaxial glass layers with a vacuum sealed between them. The vacuum stops conduction and convection, so the heat the sun puts into the inner tube stays there — even on a windy, freezing night. The inner tube carries a selective absorption coating that turns sunlight into heat with high efficiency.
Our tubes are drawn from high borosilicate glass 3.3 — the same glass family used in laboratory ware — for low thermal expansion, high transmission and long service life under daily thermal cycling.
Each family matches one collector architecture; both are standard across our catalogue.
| Tube type | Size | Used in |
|---|---|---|
| All-glass twin tube | Φ58 × 1,800 mm | SC-HP heat pipe collectors, SC-U U-pipe collectors, SC-V non-pressurized collectors, SD-S / SD-G non-pressure heaters |
| Glass–metal heat pipe tube | Φ70 × 2,000 mm | iW-HM metal-glass heat pipe collectors |
The Φ58 × 1,800 mm twin tube is the standard across our evacuated-tube range: the pressurised heat pipe solar collector, the U-pipe version, and the commercial low pressure solar collector. The same tube heats the household non-pressure solar water heater. The larger Φ70 × 2,000 mm glass–metal tube powers the iW-HM collector for high-temperature and cold-region projects.
If your project needs tubes together with collectors, tanks and mounting hardware in one container, see the full solar water heater product range.
iW Solar is a B2B manufacturer, so tubes ship the way your business needs them:
The Φ58 × 1,800 mm tube is an all-glass twin tube used in thermosiphon and heat-pipe collectors. The Φ70 × 2,000 mm tube is a glass–metal heat pipe tube with a metal absorber plate — larger aperture area and higher output for high-temperature and cold-region projects.
Yes. The vacuum layer is high temperature resistant and anti-freezing. In heat-pipe systems there is no water inside the tubes at all, so nothing can freeze and burst — those systems are used down to -35 °C.
On all-glass systems the affected loop is drained and the tube is replaced in a few minutes. On heat-pipe systems nothing drains — the rest of the collector keeps working because water never flows through the tubes.
High borosilicate glass 3.3 — low thermal expansion, high light transmission and resistant to the daily thermal cycling a solar collector endures.
Yes. Tubes are supplied as a standalone B2B product in container quantities, packed in reinforced cartons for sea freight, and can be matched to your own collector designs.
MOQ starts from 1 set for pilot projects. Production takes 18–25 working days after order confirmation, and we reply to every enquiry within 12 hours.
Tell us the tube size, quantity and destination port. We come back with a packing plan and price within 12 hours.
Request a quotation See all solar water heater productsCompetitive pricing, exceptional quality — get a factory quote within 12 hours.
If you are looking for an experienced and reliable factory for your OEM custom solar water heaters and bespoke solar equipment in China, iWSOLAR is your best choice. We offer the most reasonable price with the finest quality to support your business.