Wyes Vs Tees

When I supply do-it-yourselfers with fittings and tubing to install a central vacuum system, often I am asked why I only supply 45 degree "wye" fittings instead of the much more common 90 degree "tee" fittings. The main reason is, everything you can do with a tee, you can also do with a wye. In fact, you can make a wye into a tee just by adding a street 45 elbow. However, there are lots of things that you can do with a wye that just cannot be done nearly as well with a tee. Like this example I found during a service call in Winfield, IL recently...

Wye Fitting Replacing Tee

We have here a main trunk line that converges to the power unit mounted on the basement wall below. Arranged with a wye fitting, dirt from either side only has to make a 90 degree turn. The original setup (which I am holding up for the photo) using a tee forced dirt coming from the right to go through three 90 degree elbows, or 270 degrees in total.

I rest my case.