Plumbing Wye VS Sanitary Tee: Best Fit For Drainage System

We need a proper drainage system to divert and transport rainwater from our buildings. It helps us in keeping the environment safe. Plumbing wye and sanitary tee are two of the major parts of drainage system that seems quite similar but confuse a lot. It may confuse when choosing the best fit for a good drainage system.

The plumbing wye has three openings at 45 degrees and is connected. You can identify them by the shape that joins three pipelines together. Sanitary tee can identify by its tee shape when seeing it downward and connects the branch lines to vertical lines.

Sanitary tee and plumbing wye are used side-by-side, but difficult to differentiate that may be desperate for the primary purpose. Keep reading my below content to know the clear differences in both, which fits better than others at a specific place.

Plumbing Wye vs Sanitary Tee: Things to know

When it comes to choosing between a plumbing wye and a sanitary tee for your drainage system, there are a few key things to consider. Understanding the differences between these two fittings can help you make an informed decision that will ensure optimal drainage.

1. Plumbing Wye:

Plumbing wye is generally used when connecting the horizontally to the vertical planes. It has a standard Y shape that simultaneously connects three pipelines sequenced.

It joins the branch lines. An inlet pipe from one side enters at an angle of 45degrees and connects the other openings at the same angle. For the plumbing, wye stainless steel, carbon steel, copper, iron, and many other materials are best.

2. Sanitary Tee:

The primary purpose of sanitary tee fitting is to offer proper water drainage and vent solution to the entire plumbing system. Sanitary tee connects the branch line to the vertical lines.

You will see a molded tee shape when you see its sweep on the downside from its side view. It provides a smooth surface for the liquid to drain from proper drainage. For sanitary tee, cast iron, copper, ABS plastic, and many other materials are used.

Plumbing Wye VS Sanitary Tee: Quick Comparison Chart

Basis of comparisonPlumbing WyeSanitary Tee
Shape“ Y” shape“ T” Shape
PurposeVent for drainage and ensure the proper liquid flowJoin horizontal pipes with vertical planes and ensure proper flow of solid materials without clogging
ApplicationDrainage systemDrainage system
MaterialsCast iron, ABS plastic, copper, bronze, etc Stainless steel, carbon steel, copper, Nikle, etc

Plumbing wye VS Sanitary Tee: Key Differences

You may think it is pretty easy to differentiate sanitary tee and Plumbing wye because of their shape.

But it is not; it becomes very confusing to differentiate. You need to consider many things to identify them correctly. The below comparison may assist you in making the right decision between these two.

1. Shape:

The shape is one of the significant features that may create easy to identify and differentiate wye and tee. When you look at their shape, you will see sanitary tee will be like the letter” T” and plumbing wye shape is identical to letter” Y.”

2. Purpose:

The purpose of the sanitary tee is to connect the horizontal to vertical transition planes. Its primary purpose is to ensure proper vent system for drainage system and provide a good surface for smooth flow of liquid to keep drainage system properly functioning.

Plumbing wye connects two or three pipelines at 45 degrees angle into one horizontal line to ensure proper liquid flow without causing any clogging. There is no purpose of venting in plumbing wye except connecting different pipelines efficiently.

3. When to use:

Sanitary tee and plumbing wye both used in the drainage system and come with many benefits. You should use them at their proper place to get maximum benefits.

You can use a sanitary tee when your purpose is to rejoin the horizontal lines, such as for the waste arm to a vertical riser. It could be a good alternative in some situations for vent tee during plumbing vent lines to ensure proper liquid flow.

Plumbing wye can use when your purpose is to connect the horizontal drain pipes to the vertical position to reduce the clogging of solid items.  

Plumbing Wye is also used to separate the branch lines, which may assist you in dividing the lines into two equal lines but in opposite or different directions.

It is perfect to insert the pigging to ensure the cleanliness and clearance of pipes for proper flow.

4. Materials:

You may not find much difference when choosing material to use for sanitary tee or plumbing wye. Some commonly used materials are carbon steel, cast iron, Nikle, ABS plastic, stainless steel, etc. You can choose either one according to your budget and the nature of the project.


Can You Lay a Sanitary Tee at its Back?

Never lay the sanitary tee on its back with its side opening; it will create a big issue.
When you lay the sanitary tee on its back, it will cause an upstream splash of waste hitting the horizontal pipe bottom. It will not just cause a problem for venting but also cause clogging in the pipeline.

Could You Switch Sanitary Tee or Plumbing Wye with Each Other?

You cannot switch them because both are best for different purposes. As discussed, the primary purpose of the sanitary tee is to provide ventilation and ensure a smooth flow of liquid.
But the purpose of plumbing wye is to join different pipelines at 45-degree angles and ensure smooth flow of solid materials.

Can I use Plumbing Wye for Horizontal Connection?

No, it is only good for connecting the horizontal lines to vertical planes. If you connect the plumbing wye for horizontal, it will cause clogging.

Could I use Plumbing Wye for the Venting System?

It is not always suitable, but it could be used horizontally as a venting system in some shower, lav, or tub conditions.


Drainage system performance is closely connected with the proper installation of the sanitary tee and plumbing wye to ensure proper vent and flow of solid and liquid. But you may mess between them, install the wrong part, and face drainage problems.

Plumbing wye and sanitary tee look very similar, but their purposes and shapes are very different that makes them different, and they become suitable for different situations and places.


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