水箱外壳起保护保温层的作用，若质量不过关会导致开裂，里面的保温层直接暴露在室外，严重影响保温性能，更进一步会加重内胆腐蚀，造成漏水。外壳所用材质多样：铝合金、彩钢板、不锈钢板、镀铝锌板等。要注意的是外壳各个峁合面的接触缝隙不能太大,不能有松动和保温料溢出，外表不能有划痕,有划痕会加速腐蚀。
The water tank shell plays the role of protecting the insulation layer. If the quality is not qualified, it will lead to cracking, and the insulation layer inside will be directly exposed outside, which will seriously affect the insulation performance, and further aggravate the corrosion of the tank, causing water leakage. The shell is made of various materials: aluminum alloy, color steel plate, stainless steel plate, aluminum zinc plate, etc. It should be noted that the contact gap between the various surfaces of the shell should not be too large, there should be no looseness and overflow of insulation materials, there should be no scratch on the surface, and scratch will accelerate corrosion.