If you’ve done any plumbing work, you’ve likely come across various types of pipe fittings. One of the more common ones is the simple “T” shaped fitting called a sanitary tee. But when exactly should you use a sanitary tee in your plumbing systems? In this guide, I’ll walk you through when would you use a sanitary tee?, when and where to use them, the different types, and some installation tips. Let’s get started!
What is a Sanitary Tee?
A sanitary tee is a plumbing fitting shaped like the letter “T” that allows you to branch off at a 90 degree angle from a larger main pipe. It has three openings – one on the run going straight through, and a branch coming off the middle at a right angle.
The key feature of a sanitary tee is that it has a curving central connection rather than a flat spot like a regular tee. This curved section is specially designed to promote smooth flow and drainage, preventing any pooling of water or waste. For this reason, sanitary tees are primarily used on drainage systems rather than water supply lines.
Sanitary tees, available in a variety of sizes ranging from 1-1/2 inches to 8 inches, are designed to match different pipe diameters. These tees, crucial components in plumbing systems, are crafted from a range of materials such as PVC, ABS, copper, cast iron, and lead-free brass.
It’s worth noting the sanitary tee vs wye fitting. The choice between a sanitary tee vs wye depends on the specific plumbing needs and regulations. Each fitting serves distinct purposes, and understanding their unique characteristics is essential for proper plumbing system installation.
When Should You Use a Sanitary Tee?
Sanitary tees have some specific uses in home and commercial plumbing applications. Here are the main situations where you would need a sanitary tee:
Drain-Waste-Vent (DWV) Systems
The most common use for sanitary tees is on drain-waste-vent (DWV) plumbing systems. DWV systems carry wastewater and sewage from fixtures and drains through the pipes and out of the building.
Sanitary tees allow you to connect fixture drains, branch drains, and vent pipes into the main sewer drain line. For example, you would install a sanitary tee to connect:
- The drain pipe from a toilet into the main soil stack.
- A sink drain into a branch drain line.
- A vent pipe into the stack.
Using sanitary tees on these systems maintains proper flow and minimizes clogs.
Septic Systems
For homes with septic tanks, sanitary tees are used to connect the septic tank to the distribution box, and to join the main septic drain lines with branch lines leading to the leach field trenches.
Under Sink Drainage
You’ll often find sanitary tees connecting the P-trap under a sink to the drain tailpiece and vent line. This allows wastewater to flow smoothly while permitting proper venting.
Condensate Drain Lines
Sanitary tees can also be used on condensate drain lines from HVAC systems and water heaters to allow moisture to drain properly.
Where Should You Avoid Using Sanitary Tees?
While sanitary tees work great for drainage applications, there are some instances where you would not want to use them:
- Water supply lines – Any potable water lines should use standard tee fittings, not sanitary tees. The curved interior of a sanitary tee can accumulate mineral deposits and bacteria over time.
- Closed piping systems – Sanitary tees are intended for systems open to the atmosphere so air can flow through the branch. Using them on closed loop systems like recirculating hot water lines is not recommended.
- Low points – Avoid using sanitary tees at any low points in drainage systems where water may collect. Use a standard tee and add a cleanout instead.
- Tight spaces – The bulky central curve requires proper clearance. If space is very tight, a regular tee and 45° elbow may work better.
- Weak structural points – Sanitary tees are weaker than standard tees and more prone to breaking if subjected to excessive force or movement. Don’t use them in unconventional orientations or where they will need to support a lot of weight.
Types of Sanitary Tees
There are a few different configurations and variations of sanitary tees to suit different needs:
Standard Sanitary Tee
This is the basic style with a curved central connection and three openings – one on the run and one on the branch. It allows a 90° change of direction.
Combination Wye and 1/8 Bend Sanitary Tee
This is similar to a standard sanitary tee but the branch fitting connects at a slightly offset 87° angle rather than 90°. The run is also angled at a 3° slope. This allows installations where the pipes do not meet at precise right angles.
Double Sanitary Tee
A double sanitary tee has four openings. It combines two sanitary tee sections into one fitting. This allows you to branch off in two directions from the same run.
Sanitary Cross
A sanitary cross is like a double sanitary tee but the second branch comes off the other side rather than in line, forming a cross shape. All four inlets have curved connections.
Reducing Sanitary Tee
This is a sanitary tee with fittings of different sizes – normally a larger run and smaller branch. It adapts between pipe diameters.
Sanitary Tee Wye
Also called a branch tailpiece sanitary tee, this style has a curved inlet run, a straight branch, and an angled outlet. Useful for connecting horizontal and vertical pipes.
Tips for Installing Sanitary Tees
When installing sanitary tees, follow these guidelines for optimal performance:
- Mind the direction – Sanitary tees are designed to be installed with the branch inlet on top to promote drainage. Flipping them will impede flow.
- Glue all connections – Use the appropriate primer and solvent glue to permanently bond all sanitary tee joints. This prevents leaks and slippage. Avoid thread-connected tees.
- Support the branch – Secure heavy branches with additional brackets/hangers to prevent strain on the sanitary tee joint. Don’t let all the weight bear down directly on the fitting.
- Maintain slope – The branch inlet should slope slightly back towards the main run at 1/4 inch per foot. This keeps drainage flowing in the right direction.
- Watch alignment– Branches should intersect the main run at a 90° angle. Installation may be easier using a combination sanitary tee that allows for some angular misalignment.
- Provide access – If the sanitary tee is in a difficult to reach location, install a cleanout on the branch to enable future access if needed.
Following the manufacturer’s recommendations for preparation, assembly, cure times, and orientation is also important. With good installation practices, a sanitary tee should provide years of smooth and trouble-free drainage.
FAQs
Can you use a sanitary tee on its back?
No, sanitary tees are designed to be installed upright with the branch inlet on top. Flipping them over will disrupt proper flow.
What’s the difference between a sanitary tee and standard tee?
Sanitary tees have a curved central connection optimized for drainage, whereas standard tees have a flat central section and are used more often in water distribution lines.
Are sanitary tees always made of plastic?
No, sanitary tees come in various materials like PVC, ABS, cast iron, copper, and lead-free brass depending on the type of system. Plastic is most common for DWV.
Can I use a sanitary tee to go from a larger to smaller pipe?
Yes, you can get reducing sanitary tees to transition between different pipe diameters like moving from a 3″ to a 2″ drain line.
How do I clean out a clogged sanitary tee?
You can snake a drain auger through the straight run of the tee to clear clogs. Also install a cleanout cap on the branch above the floor to provide access. Avoid disassembly if possible.
Conclusion
While they may seem simple, sanitary tees play an important role in allowing proper drainage and venting in plumbing systems. Their distinguishing feature is the curved central connection that maintains smooth water flow and helps prevent blockages and leaks.
Exploring the intricacies of well pump functionality in how does a well pump work: A comprehensive guide, one must also recognize the importance of proper plumbing connections in residential DWV systems, where sanitary tees play a crucial role in linking fixtures, drains, and vents to the main waste and vent stacks; caution is advised to avoid their use outside drainage applications.
With the right installation practices like proper orientation, glued joints, and branch support, a sanitary tee should provide problem-free performance. Paying attention to sizing, angles, and access will result in a long-lasting sanitary tee application.
