applied to deflect the wall 40 inwardly is removed the insert wall 40 will deflect outwardly thereby increasing friction between the lip 94 and the strainer wall 28 to facilitate insertion of the angled wall a taper not shown may be provided on the lip 94 so that when engaged onto the strainer wall 28 the insert wall 40 will be deflected inwardly furthermore those of skill in the art will appreciate that opposed to a continuous insert wall 40 many elongated tabs or walls may be provided fig1 is an alternate embodiment wherein a conical wall 98 is provided the conical wall 98 includes an inner lip 102 that receives a sliding ring 106 in operation the sliding ring 106 is placed into the strainer wall 28 and moved downwardly thereby deflecting the sides of the insert wall 40 outwardly to place the lip 94 in engagement with the strainer wall 40 again one skilled in the art will appreciate that opposed to a continuous wall many tabs or subwalls may be provided by this embodiment of the present invention fig1 an alternate embodiment of the present invention is shown wherein an adhesive 110 is used between the insert flange 36 and the strainer body flange 24 an engaging lip 38 may also be included to help center the insert 34 with respect to the strainer body 20 fig1 shows yet another.