If you’ve ever worked on a plumbing, HVAC, or fluid system project—whether as a seasoned tradesperson, a DIY enthusiast tackling a bathroom reno, or a builder overseeing a new residential development—you’ve probably stumbled on push fit fittings. For those of us who supply these parts, one of the most common questions we get at our company isn’t about durability or material, it’s straightforward: Do Push Fit Tees come in different sizes? The short answer is a resounding yes, but there’s a lot more nuance to it than a simple size chart. Today, I want to break down how size works for Push Fit Tees, why it matters for your project, and how to pick the right one to avoid leaks, delays, or headaches down the line.
Let’s start with a quick refresher for anyone new to push fit technology. Push fit fittings are the modern workhorses of fluid systems, designed to let you connect pipes, valves, or other components without solder, clamps, or specialized tools. You just push the pipe into the fitting, and the stainless steel collet inside grips the pipe tightly, while an EPDM or nitrile rubber seal creates a watertight, airtight bond. They’re faster to install than traditional fittings, easier to work with in tight spaces, and versatile enough for use with copper, PEX, CPVC, and even some HDPE pipes.
A Push Fit Tee, in particular, is a three-way fitting that lets you split a pipe line into two directions—think of it as a T shape where you have one inlet and two outlets, or vice versa. These are critical for systems that need to branch off: adding a bathroom to a main water line, installing a secondary HVAC zone, or routing gas to two separate appliances. But here’s the thing: not all Push Fit Tees are made the same, and size is the first (and most important) factor to get right.
So what “sizes” are we talking about here? For push fit fittings, size refers almost always to the outer diameter (OD) of the pipe they’re designed to connect. Unlike traditional threaded fittings that use nominal pipe size (NPS), which is a rough name for the inside diameter, push fit sizes match the exact outer measurement of the pipe. That’s a key detail—if you’re working with 15mm copper pipe, you need a 15mm Push Fit Tee, not a 1/2 inch threaded fitting, even though they’re roughly equivalent.
Now, the range of sizes available for Push Fit Tees is pretty broad, spanning from small 6mm tees for compact applications like water filter lines or refrigerator ice makers, all the way up to 54mm tees for large commercial plumbing or industrial fluid systems. Residential and light commercial projects tend to use the most common sizes: 10mm, 15mm, 22mm, 28mm, and 35mm. For example, a standard home’s main cold water line might use 22mm or 28mm pipe, so a tee for that line would match that OD.
But it’s not just the inlet and outlet sizes that matter—Push Fit Tees also come in equal and reducing configurations. An equal tee has three openings of the same size, perfect for splitting a 15mm line into two 15mm branches. A reducing tee, on the other hand, has one main opening and two smaller (or occasionally one larger) openings, so you can split a 22mm line into a 22mm main run and a 15mm branch. That flexibility is why tees are so popular, and it’s a key part of why size variety matters. A lot of first-time installers make the mistake of using an equal tee for a reducing application, and end up with a leak or reduced flow because the pipe isn’t a tight match.
Wait a second, you might be thinking—what about other push fit fittings? How does size work there? Well, it follows the same pipe OD standard, but their design is tailored to their specific job. For example, a Push Fit Elbow is a 90 or 45-degree turning fitting, used to route pipes around corners in tight spaces, so they come in the same size range as tees. A Push Fit Coupling is a straight fitting that connects two lengths of pipe, so you’ll find them in every common pipe size too. Then there are specialty fittings like the Push Fit X Mpt Adapter, which connects a push fit pipe to male pipe thread, or the Push Fit X Mpt Elbow, which is a 90-degree version of that. Both of these specialty adapters also come in the same size increments as standard tees and elbows, so you can mix and match fittings without worrying about compatibility.
But here’s a question we get all the time: why can’t I just use one size for all my projects? The answer is flow rate and pressure. If you undersize a tee for a high-flow main line, you’ll restrict the water or gas flow, leading to slow taps, weak shower pressure, or even system damage over time. If you oversize a tee for a small branch line, you’ll have gaps that the collet can’t grip properly, leading to leaks. That’s why matching the tee size to your pipe’s OD is non-negotiable. For example, if you’re running a sprinkler system line with 28mm pipe, a 28mm Push Fit Tee will handle the full flow rate of that line, while a smaller 22mm tee would cut flow by nearly 50% and strain your pump.
Another important factor is material compatibility, which ties into size too. Our Push Fit Tees are made from lead-free brass, which is the industry standard for potable water systems because it’s corrosion-resistant and safe for drinking water. But brass is rigid, so the manufacturing tolerance for the fitting’s opening is tight—within a fraction of a millimeter of the pipe’s OD. That’s why you can’t force a 15mm pipe into a 22mm tee, and why we always recommend measuring your pipe’s outer diameter with a caliper if you’re unsure, rather than relying on nominal size names. We’ve seen too many projects go wrong because someone thought 1/2 inch was the same as 15mm, but different pipe manufacturers use slight OD variations, so verifying with a caliper saves a lot of hassle.
Now, let’s talk about how size varies across different types of push fit fittings, just to keep things clear. If you’re browsing our site, you’ll see that our Push Fit Tee line covers sizes from 6mm to 54mm, with both equal and reducing options. Our Push Fit Elbow line has the same size range, as do our Push Fit Couplings, adapters, and elbows. The specialty fittings like the Push Fit X Mpt Adapter and Push Fit X Mpt Elbow also follow this size standard, so you can seamlessly connect threaded components to your push fit pipe without sizing mismatches.
Wait, but what about metric vs. imperial sizing? That’s a common point of confusion, especially for projects that mix international components. Most of our fittings and our entire catalog are metric, which is standard in plumbing and HVAC worldwide, but we do offer conversion guides for imperial sizes for customers who work with older systems or North American installations. For example, a 15mm metric tee is roughly equivalent to a 1/2 inch imperial tee, and a 22mm is equivalent to 3/4 inch. We always recommend checking our product pages for exact size conversions, because even small differences can affect fit.
Let’s also address a common myth: some people think that Push Fit Tees only come in standard sizes, but that’s not true for our range. We also offer custom-sized Push Fit Tees for specialized industrial applications, like those used in chemical processing or medical gas systems, where custom pipe sizes are required. That’s another benefit of push fit technology—its modular design makes it easy to adjust sizes for non-standard projects, something traditional threaded fittings can’t offer as easily.
Now, why does this size variety matter for our customers? Whether you’re a residential plumber doing a kitchen remodel, a commercial contractor building a new office, or an industrial engineer designing a fluid system, having access to the right size Push Fit Tee means less downtime, fewer callbacks, and a longer-lasting system. A leaky fitting isn’t just an inconvenience—it can damage drywall, ruin flooring, or lead to costly water damage claims. Choosing the correct size from the start eliminates that risk.
So how do you pick the right size for your Push Fit Tee? Let’s walk through a quick step-by-step guide, based on what we recommend to our customers. First, identify the type of pipe you’re working with (copper, PEX, CPVC, HDPE) and measure its outer diameter exactly. Second, determine if you need an equal tee or a reducing tee—equal if all three runs are the same size, reducing if one run is larger or smaller. Third, cross-reference your measurement with our size chart on our Push Fit Tee product page, and make sure to account for any reducing requirements. Finally, double-check that any other fittings you’re using (like elbows, couplings, or adapters) match that same size, to avoid compatibility issues.
For example, let’s say you’re adding a new bathroom sink to your existing plumbing. Your main line is 22mm copper, and the sink supply lines are 15mm. You’d need a reducing Push Fit Tee with a 22mm main inlet and two 15mm outlets. That same size would work with a 15mm Push Fit Elbow for the sink’s angle stop, and a 15mm Push Fit Coupling if you need to extend the supply line. If you needed to connect that 15mm pipe to a threaded valve, you’d use a 15mm Push Fit X Mpt Adapter, which is sized to match perfectly.
At our company, we specialize in providing push fit fittings for every project, big or small, and we’ve built our reputation on clarity when it comes to sizing. We know that plumbing and HVAC can be confusing, especially when you’re staring at a pile of fittings and pipes trying to figure out what fits. That’s why we include detailed size charts on every product page, including our Push Fit Tee, Push Fit Elbow, Push Fit X Mpt Adapter, Push Fit X Mpt Elbow, and Push Fit Coupling, so you never have to guess. We also have a team of technical experts who can help you size a fitting correctly, even for custom applications.
Let’s touch on a recent project that highlights why size matters. A few months back, we worked with a residential contractor who was doing a whole-house repipe. He ordered 15mm Push Fit Tees for all the branch lines, but accidentally ordered equal tees instead of reducing ones for his main line branches. When he started installing, he realized that the 15mm tee was too small to connect to the 22mm main line, and the larger tee would have restricted flow. He ended up missing his deadline because he had to reorder the correct reducing tees, and he told us afterward that he wished he’d known about the size guide on our site before he placed the order. That’s exactly why we make that information easy to find—we want to help our customers avoid those mistakes.
Another point: size also affects pressure rating. All our Push Fit Tees are rated for up to 16 bar (232 psi) for most sizes, which is more than enough for residential, commercial, and most industrial applications. But larger tees (over 35mm) have slightly lower pressure ratings, around 10 bar, because thicker walls are needed to maintain rigidity for bigger pipes. That’s a good thing to keep in mind if you’re working with high-pressure systems—you need to make sure not only that the tee size matches your pipe, but also that its pressure rating fits your system’s needs.
So to circle back to our original question: Do Push Fit Tees come in different sizes? Absolutely. They come in a wide range of metric sizes, from tiny 6mm tees for appliance lines to large 54mm tees for industrial systems, with both equal and reducing configurations. And that size variety extends to all push fit fittings, from elbows and couplings to specialty adapters like Push Fit X Mpt Adapters. The key is matching the tee’s size to your pipe’s outer diameter, and choosing the right configuration for your branch needs.
At the end of the day, the last thing you want for your project is a leaky fitting that leads to extra work and extra cost. That’s why taking the time to get the size right from the start is worth every minute. If you’re not sure which size Push Fit Tee you need, or if you have questions about any of our fittings—including our Push Fit Elbow, Push Fit X Mpt Adapter, Push Fit X Mpt Elbow, or Push Fit Coupling—our team is here to help. We can walk you through sizing, answer technical questions, and make sure you get the right parts for your project, on time.
When you’re ready to place an order or discuss your project needs, don’t hesitate to reach out. We’re dedicated to supporting tradespeople, DIYers, and builders with high-quality push fit fittings that make their jobs easier and their systems more reliable.
References
- International Plumbing Code (IPC) 2021, Chapter 6: Plumbing Fixtures and Equipment.
- ASTM F1960: Standard Specification for Push-In Fittings for Copper and Plastic Pressure Piping Systems.
- Brass Industry Association (BIA) 2022: Lead-Free Brass Fitting Standards for Potable Water Applications.
- ASME B1.20.1: Pipe Threads, General Purpose (Imperial) for adapter sizing conversions.
- Push Fit Fitting Manufacturer Association (PFFMA) 2023: Size Tolerance Guidelines for Metric Push Fit Components.
