27 27 39 can optionally be bonded to the side wall by welding an adhesive or other suitable methods or can be optionally further secured by screws bolts or rivets placed through holes 43 43 39 formed in the flanges referring to fig2 and 12 spacers 33 35 lower side flange 27 and the wall of outer casing 24 define slots 85 86 87 therebetween slots 85 39 86 39 87 39 are similarly defined on the opposite side of casing 24 slots 85 86 and 87 are slightly offset in a vertical direction from corresponding slots 85 39 86 39 87 39 the purpose of the offset is to allow a heating tape or coil not shown well known in the art to be threaded therethrough in a spiral fashion the heating tape or coil is desirable when the trap 20 is subjected to freezing temperatures in order to prevent the fluids therein from solidifying and defeating the function of the trap lower side flange 27 39 is slightly offset vertically from lower side flange 27 to accommodate the slot offsets however lower side flanges 27 27 39 function identically when trap 20 is engaged with side wall 81 heat tape can also be coiled and placed against the rear surface of half casing 24 between the spacers 33 35 and 33 39.