Which reason can cause water tank break? (Non pressure solar water heater)

Water tank's Vent was blocked
When the vent is blocked, when water come into or go out from the water tank, the air in the water tank cannot fill in or goes out, the space for air is changing, the pressure of the air will grow up or drop down a lot. The big difference pressure between inside tank and outside will cause the water tank inflate or burst.

Products Guide