Sanitary Tees Main Types
1. Sanitary tee
A sanitary tee has a curved center section. In drainage systems, it is primarily used to connect horizontal drains to vertical drains. The center connection is usually to the pipe leading to a trap. It should not connect a vertical drain to a horizontal drain, because of the likelihood that solids will build up at the bottom of the junction and cause a blockage.
2. Double sanitary tee (sanitary cross)
This sanitary fitting differs from a standard cross in that two of the ports have curved entrances. Although it has been used in the past to connect back-to-back fixture drains, some current codes—including the 2006 Uniform Plumbing Code in the US—prohibit the use of this fitting for that purpose and require a double luminaire fitting to minimize wastewater from one side flowing into the other.
3. Wye (Y) fitting
The Wyes are similar to tees, with the exception of tilting the bypass line to reduce friction and turbulence. They are commonly used to attach a vertical drain to a horizontal pipe. The connection is usually 45 degrees rather than 90 degrees. If a branch is further away at 90 degrees, the fitting becomes a combo tee. Wyes and combo wyes follow a long sweeping pattern compared to sanitary tees and other short sweeps, which have a smaller radius and require less space. A wye can also be used to divide a bypass line evenly in two directions, such as dividing a main line into two smaller branches.