Solar water heater project for school 1. Suitable for hotel, school, swimming pool, sub district; 2. Economic cost; Solar water heater ... argon arc welding, which is very durable with high density;b) Outer water tank: galvanized steel;c) Bracket: galvanized steel / aluminum ... solar vacuum tubea) Size: Φ47x1, 500mm / Φ58x1, 600mm / Φ58x1, 800mm;b) Hail resistance: 25mm.