top vent tee integral tee trap outside furnace left hand horizontal end vent tee integral tee trap outside furnace right hand horizontal top vent tee and integral tee trap outside furnace right hand horizontal end vent tee and integral tee trap outside furnace additionally the integral tee trap can be rotated to provide drainage in desired direction and also used with a standard off the shelf tee to provide drainage and trapping the tee is designed to combine the wall thicknesses of standard schedule 40 pvc fittings with the small socket size of standard dwv pvc fittings to create a more compact design with maximum strength and compatible with standard pvc pipe and components together the parts provide a drainage and trapping system that is adaptable to more installation configurations than prior art in a further application the icp top of the line deluxe furnaces have a wide casing and the tee can be used inside the furnace for top venting fig5 a or outside like 5 b amp c the icp standard furnaces less expensive models are narrower and can only be installed with the tee and trap outside the casing fig5 b amp c this is an important difference because upflow fig5 a b amp c comprises 80 of installations since these models compete in price sensitive markets reducing costs by not shipping the special tee in the standard units and allow the installer to use an off the shelf tee is a valuable option it can therefore be seen that the tee 39 s flexibility allows us to provide differentiation in a tiered product line while using minimum.