and the upper canister 2 in order to avoid any settling or shifting of the filler contents during handling and shipping desirably the filler material may be formed of polyurethane foam the inner fluid container 20 is formed of seamless construction throughout to provide easy and complete drainability in an inverted position and to prevent undesirable retention of any of the fluid contents during cleaning procedures the canister base 4 is formed of a double wall construction with the inner surface of the canister base 4 generally conforming to the shape of the bottom of the inner fluid container 20 as a support diaphragm 40 the middle of the inner surface of the canister base 4 has a liner socket cup 44 to accommodate the well 42 on the bottom of the inner fluid container 20 the interior of the double wall construction of the canister base 4 is filled with filler material of the same composition and preformed construction as that used for the filler 22 in the space between the inner fluid container 20 and the upper canister 2 in addition to the support provided by the support diaphragm 40 the inner fluid container 20 is supported by contact with the concentric inward directed flange 48 at the bottom of the side wall of the upper canister 2 and by contact with the neck opening in the middle of the top surface of the upper canister 2 the bottom of the canister base 4 terminates in a protruding concentric foot ring 46 which is sized and positioned to nest just inside the circular stacking crown 8 on the top surface of the upper canister 2 as shown in fig2 the neck of the inner fluid container 20 has threads 32.