Water heater apparatus and associated manufacturing and insulation methods

摘要

A method of insulating a tank (14) comprising the steps of: placing an outer jacket (28) on the tank to define a cavity (26) extending outwardly around a portion of the tank; positioning a flexible bag (42) having a substantially closed upper end portion with a relatively small injection opening (56) and associated vent opening (58) therein in a first portion of the cavity; forcing a first quantity of insulation (66) to be packed under pressure within the bag; and flowing a second quantity of flowable insulation (40) into a second portion of the cavity and into contact with the bag.