... will be gradually heatedSolar hot water heaters features 1. Cheap and reliable solution, Simple structure, Easy installation 2. High efficiency 3. ... steelTank insulating layer55mm 45kg/m³ high-density polyurethane foamedInlet and outlet holeMale G 1/2, 3/4Max pressure0.05 ... tank:4 holes for air vent,overflow,water inlet and outlet,electric heaterWelding:Argon arc weldingFastening pieces:Made of ...