Damage to any object is a process, as is damage to a FRP tank, and it is also a staged process: 1. The phenomenon of the initial damage period, which is due to the convergence of the corrosion process and the convergence of the tensile stress, the metal surface gradually forms a number of initial mechanical cracks. The stress concentration in the metal surface can be caused by uneven internal stress, defects in the metal surface (Abrasions, machining textures, cracks, interlayers, etc.) and disconnection of the structural shape. 2. Corrosion crack development period, this period is the beginning of Corrosion: The process of Mechanical Crack Repair and further development under the combined effect of the electrochemical effect of the corrosive medium and the primary tensile stress in the metal. The general direction of crack propagation is generally straight from the direction of the principal tensile stress. 3. At the end of the damage period, as the crack expands further, one of the cracks will grow faster than the others because the tensile stress becomes larger and larger, moreover, the expansion of other cracks will be excluded and the primary tensile stress will be transferred to this primary crack, which will result in the cracking of the member. During this period, the cracking is in the mechanical elements of the primary effect of the case, and the more late, the mechanical elements played the greater effect. So in order to better extend the service life of FRP tanks, tanks need to be maintained and maintained on an irregular basis, so in FRP tank maintenance period should pay attention to what? ! Personal Safety is everything ！! 1. When entering the FRP tank for maintenance, all feed valves should be closed, the tank should be emptied and cleaned, no toxic gas in the tank should be tested and confirmed, no oxygen shortage can enter the tank, entering the tank should wear soft-soled shoes, fasten your seat belt and attach the other end of the belt to the top of the tank. Note that the tank is ventilated. Operation into the tank must be carried out under the supervision of personnel outside the tank. 2. To prevent tools from hitting the tank wall, use ladders, metal parts equal to the part of the tank wall contact to add soft cushion, to protect the inner wall from being split, contusion. 3. The external climbing ladder, cage, guardrail of frp storage tank should be carefully checked before climbing to ensure safety and reliability. Any abnormal condition is strictly forbidden to climb. 4. The tank top shall not be loaded at random during maintenance and external force shall not be applied on the nozzle. 5. FRP tanks for outdoor use after many years of use due to the surface layer of aging, resulting in resin layer peeling or fiber exposed. It is suggested that paint or resin should be applied on the surface of the tank every two or three years to prevent aging and prolong its service life. In the maintenance process, especially to pay attention to safety issues, must check all the equipment before the FRP tanks for maintenance.