leaking Problem of The Water Tank?

How to solve the leaking problem of the hot water tank?
We made some analysis based on installation and maintenance experiences as following:
1. Inner tank corrosion
The inner tank corrosion usually caused by local bad water quality, especially in the coastal areas. Cl and SO ion in the water (PPM>180mg/L) would corrode the inner tank.
Solution: replace the tank by SUS 316L inner material, or use the copper coil close loop thermosiphon system.
Attention area: coastal areas like Netherlands, Belgium, Italy or Mid-east like Jordan, Lebanon, etc.

2. Some of the welding position of the tank break
Some of the welding position of the tank break, especially the inlet/outlet. These breaks can’t be repaired or too expensive to be repaired.
Solution: replace by new tank.

3. Shrunken of the inner tank
Shrunken of the inner tank and which result the twist of the sealing rubber ring or other related outlet parts, the sealing system was damaged to leak. If the heat time is short to the solar water heater, however the water in the tank runs out with not long time, which could be caused by shrunken of the inner tank. The installation personnel without professional training would make the errors that the gas vent blocked or thinned. Elbow or bibcock added to the end of the overflow indoor by the users for beauty without the knowledge that the overflow pipe also has ventilatory function.
Shrunken of the inner tank usually appears in winter. The water level is high, however, the temperature of the original water in the tank is too low, the air vent would be blocked by the ice. Once the inner tank shrunken, the tank scrap.
Solution: ask the distributer to replace a new tank if caused by installation.

4. Sealing rubber ring worn, aged
Sealing rubber ring worn, aged. Clutters stick to the inner circle of the sealing ring would effect the sealing between the sealing rubber ring and the vacuum tube and venting or inlet/outlet components which would cause water seepage.
Solution: replace the sealing rubber ring.
Hot water tank users should treat the leaking phenomenon cautiously. The water would infiltrate into the insulation layer which would make the tank fail to preserve heat.