Trap-type drain fitting

A trap-type drain comprising:

• a base having
• a floor,
• an annular wall extending upwardly from said floor and having a circularly annular base rim centered on an axis,
• an annular inner wall having an upper inner-wall edge, forming with said floor a well, and forming with said floor and said outer wall an annular upwardly open compartment, and
• an outlet connection opening through said outer wall into said compartment at a level below said inner-wall edge;
• an intermediate part above said compartment and having
• a circularly annular part outer edge complementarily interfitting with said base rim for rotation of said intermediate part about said axis,
• an annular part rim generally centered on said axis above said part outer edge,
• an upright inlet tube having a lower end in said well below said inner-wall edge and an upper end above said inner-wall edge and below said part rim, and
• an inlet connection connected to said upper end of said tube and extending horizontally over said base rim between said part rim and said part outer edge;
• an insert having
• an outer insert edge complementarily interfittable with said part rim, and
• a downwardly extending drain tube having a lower end in said well below said inner-wall edge and above said floor;
• and
• means including a bayonet coupling between said part rim and said outer insert edge for sealingly locking said insert to said intermediate part.