摘要 |
A water heater for containing water surrounded in spaced apart relationship by an outer shell includes a sleeve of insulation material, such as fiberglass, located in the annular space between the inner tank and outer sleeve. The top edge of the insulation sleeve includes an annular cuff which is of a radial thickness greater than the radial thickness of the rest of the insulation sleeve such that the cuff is compressed between the interior wall surface of the outer shell and excterior wall surface of the inner tank. An expanded foam thermal insulation material fills the annular space above the cuff of the insulation mat. A method of making a water heater includes the steps of locating a sleeve of insulation material around the exterior wall surface of the inner tank, folding the top end of the insulation sleeve back over itself to form an annular cuff, and positioning the outer shell concentrically over the inner tank whereupon the annular cuff is compressed between the interior wall surface of the outer shell and exterior wall surface of the inner tank. The annular space above the annular cuff of the sleeve is then filled with an expandable foam insulation material which is allowed to foam in situ.
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