Are you in the middle of a plumbing project involving plastic pipes and wondering if compression fittings are the way to go? Well, you’ve come to the right place! Compression fittings are a popular choice in plumbing for their ease of installation and secure connections, but can you use compression fittings on a plastic pipe?
Yes, you can use compression fittings on a plastic pipe. However, it’s important to use the appropriate compression fitting designed for the specific type of plastic pipe being used to ensure a secure and leak-free connection.
In this article, we’ll explore the ins and outs of compression fittings on plastic pipes, including which fittings are compatible and why choosing the right one is crucial.
Let’s get started!
Can you Use Compression Fittings on a Plastic Pipe?
Compression fittings are a type of plumbing fitting widely used in residential and commercial plumbing projects. These fittings are designed to connect two pieces of tubing or pipe together, and they work by compressing a gasket or ring around the pipe to create a tight, leak-proof seal.
Compression fittings are popular in plumbing projects because they are relatively easy to install and require no special tools or equipment. They are also versatile, as they can be used with various pipe materials, including copper, PVC, and plastic.
However, when working with plastic pipes, using the right compression fitting is especially important because plastic pipes have different flexibility and thermal expansion levels than metal pipes. Using the wrong type of fitting can lead to leaks, cracks, and other issues.
Plastic pipes require fittings designed specifically for plastic pipes, as metal fittings may not be compatible with plastic material.
So, selecting the appropriate compression fitting for the type of plastic pipe used is essential to ensure a secure and reliable connection.
Types of Plastic Pipes You Can Use with Compression Fittings
PVC (polyvinyl chloride) pipes
PVC is a popular choice for plumbing because it’s lightweight, durable, and easy to install. PVC pipes are also resistant to corrosion and chemicals, which makes them ideal for transporting drinking water and other fluids.
You can use PVC pipes with certain types of compression fittings, such as those made from brass or stainless steel but ensure that the fittings are rated for use with PVC pipes.
CPVC (chlorinated polyvinyl chloride) pipes
CPVC has similar properties to PVC pipes but with added heat resistance. This makes them suitable for use in hot water systems, such as for showers and sinks.
CPVC pipes can also withstand higher pressures than PVC pipes. Regarding compatibility with compression fittings, CPVC pipes can also be used with certain types of compression fittings, such as those made from brass or stainless steel. Again, ensure that the fittings are rated for use with CPVC pipes.
PEX (cross-linked polyethylene) pipes
PEX has become increasingly popular in plumbing because it’s flexible, easy to install, and less likely to burst in freezing temperatures. PEX pipes are also resistant to scale and chlorine, which can prolong their lifespan.
You can use PEX pipes with certain types of compression fittings, such as those made from brass or poly alloy. Just ensure the fittings are rated for use with PEX pipes and the specific type of PEX being used (PEX-A, PEX-B, or PEX-C).
Types of Compression Fittings For Plastic Pipes
As a DIY enthusiast or a professional plumber, it’s important to know the different types of compression fittings available for plastic pipes and their differences in design and function.
Let’s take a closer look
Standard Compression Fittings
it’s the most commonly used type of compression fitting. This compression fitting consists of three main components: the body, the nut, and the ferrule. The body is a cylindrical piece of metal that fits over the end of the pipe or tubing. The nut is a threaded piece that screws onto the body, compressing the ferrule against the pipe or tubing as it tightens. The ferrule is a small ring that sits between the body and the nut and is designed to create a tight seal as it is compressed against the pipe or tubing.
To use a compression fitting, the pipe or tubing is first cut to the desired length and inserted into the body of the fitting. The ferrule is then slid over the end of the pipe, followed by the nut, which is screwed onto the body. As the nut is tightened, it compresses the ferrule, creating a tight seal between the pipe and the fitting.
You can use it often when pipes or tubing need to be easily disconnected and reconnected, such as in water filtration systems or air compressors.
Push-fit Compression Fittings
Push-fit compression fittings are a type of plumbing fitting used to connect two pipes together. They are designed to be quick and easy to install, requiring no special tools or skills, and are suitable for use with a wide range of pipe materials, including copper, PEX, and CPVC.
The fittings work by using a combination of compression and gripping mechanisms to create a tight, leak-proof seal. They typically consist of a body or sleeve that fits over the end of the pipe, a compression ring or collet that grips the pipe, and an O-ring or gasket that creates a seal between the fitting and the pipe.
To install a push-fit compression fitting, simply insert the pipe into the fitting until it reaches the stop, then tighten the compression ring or collet using a wrench or pliers. The compression mechanism will grip the pipe and create a seal, while the O-ring or gasket will prevent leaks.
Push-fit compression fittings are often used in situations where traditional compression fittings are difficult to install or where soldering is not possible or practical. They are commonly used in residential and commercial plumbing systems for hot and cold water, as well as in heating systems and gas pipelines.
Grip and Seal Compression Fittings
These fittings are designed to grip and seal the pipe without the need for a compression ring. They consist of a compression nut, a compression fitting body, and a seal.
To install, the seal is inserted into the fitting body, and the pipe is inserted into the fitting. The nut is then tightened onto the fitting body, compressing the seal onto the pipe to create a tight seal. Grip and seal compression fittings are ideal for use with soft plastic pipes, such as PVC or PEX.
Quick-Connect Compression Fittings
These fittings are designed for easy installation and removal, consisting of a compression nut, a compression fitting body, and a quick-connect adapter. The adapter allows for easy connection and disconnection of the pipe without needing tools.
To install, the nut is tightened onto the fitting body, compressing the ring onto the pipe, creating a tight seal. Quick-connect compression fittings are ideal for situations where frequent disconnection and reconnection is necessary.
How to Use Compression Fittings on Plastic Pipes
Using compression fittings on plastic pipes is a relatively straightforward process, but it’s important to take the proper steps to ensure a secure and leak-free connection.
Here’s a step-by-step guide to help you use compression fittings on plastic pipes:
Materials and tools you will need
- Compression fittings designed for plastic pipes
- Plastic pipes
- Pipe cutter or hacksaw
- Deburring tool
- Adjustable wrench
- Teflon tape (optional)
The Steps
Step 1: Cut the plastic pipe to length
Cut the plastic pipe to the desired length using a pipe cutter or hacksaw. Make sure the cut is clean and straight. Use a ruler or measuring tape to measure the length of the pipe needed before cutting.
Step 2: Deburr the cut end of the pipe
Use a deburring tool to remove any rough edges or burrs from the cut end of the pipe. This will help the compression fitting slide onto the pipe smoothly and ensure a tight seal.
Step 3: Slide the compression nut and ferrule onto the pipe
Slide the compression nut and ferrule onto the end of the pipe. Ensure that the ferrule is placed onto the pipe first, followed by the compression nut. This will help create a tight seal when tightened onto the fitting.
Step 4: Insert the pipe into the compression fitting
Insert the end of the pipe into the compression fitting. Ensure that the pipe is fully inserted and seated against the fitting shoulder. The shoulder is the small lip inside the fitting that stops the pipe from being pushed too far into the fitting.
Step 5: Tighten the compression nut
Use an adjustable wrench to tighten the compression nut onto the fitting until it is snug. Avoid overtightening, as this can damage the plastic pipe and cause leaks.
If you are concerned about overtightening, wrap Teflon tape around the threads before tightening the compression nut. This will help create a tighter seal without needing to over-tighten the nut.
Step 6: Check for leaks
Turn on the water supply and check for leaks at the compression fitting. If you notice any leaks, tighten the compression nut slightly and check again until the connection is leak-free.
If the connection still leaks after tightening the nut, the ferrule or compression nut may be damaged and will need to be replaced.
Pros and cons of using compression fittings on plastic pipes
Pros
Easy installation
Compression fittings are relatively easy to install and require fewer tools compared to other types of fittings. They can be installed by hand or with the use of a wrench or pliers, which means that installation can be completed quickly and with minimal fuss. This makes compression fittings an attractive option for DIY enthusiasts and homeowners who want to undertake plumbing work themselves.
No special skills required
Installing compression fittings does not require specialized training or skills, making it accessible to many people. Unlike other types of fittings that require specialized tools or knowledge to install, compression fittings can be installed by anyone with basic plumbing knowledge.
Leak-proof
When installed correctly, compression fittings provide a secure, leak-proof connection. This is because the compression fitting grips the plastic pipe tightly, creating a seal that prevents water or gas from leaking out. This makes compression fittings ideal for use in situations where leaks can be dangerous or costly, such as in gas or water supply lines.
Reusable
Compression fittings can be easily removed and reused, making them a cost-effective option. The compression ring or sleeve that creates the seal can be removed without damaging the plastic pipe, allowing the fitting to be reused in another location or application. This makes compression fittings an attractive option for temporary plumbing installations or situations where pipes need to be moved or repositioned.
Versatile
Compression fittings are compatible with a wide range of plastic pipes, making them a versatile option for many applications. They can be used with pipes made from materials such as PVC, CPVC, PEX, and ABS, among others. This makes compression fittings a popular choice for a wide range of plumbing applications, from residential to commercial and industrial installations.
Cons
Cost
Compression fittings can be more expensive than other types of fittings, which may be a barrier for some. While the cost of compression fittings can vary depending on the material and size of the fitting, they are generally more expensive than other types of fittings, such as threaded or push-to-connect fittings. This can be a disadvantage for those on a tight budget.
Potential for over-tightening
Over-tightening a compression fitting can damage the plastic pipe and lead to leaks. If the compression fitting is tightened too much, the plastic pipe can be crushed or damaged, which can compromise the integrity of the seal. This can result in leaks or other plumbing problems. Care must be taken when tightening compression fittings to ensure they are not over-tightened.
Limited temperature and pressure range
Compression fittings may not be suitable for high-temperature or high-pressure applications. While compression fittings can handle a range of temperatures and pressures, there are limits to what they can withstand. For example, some compression fittings may not be suitable for use in hot water supply lines or high-pressure gas lines. This means that other types of fittings may need to be used in these situations.
Limited compatibility
While compression fittings are compatible with many types of plastic pipes, they may not work with all types. Some plastic pipes may have different dimensions or thicknesses, which may require specialized compression fittings.
Some plastic pipes may not be suitable for compression fittings, which may require other types of fittings to be used instead.
Length restrictions
Compression fittings may have length restrictions, which may limit their use in some applications. This is because compression fittings rely on the compression ring or sleeve to create the seal, which may be unable to grip the plastic pipe if it is too long.
Safety considerations when working with compression fittings on plastic pipes
When working with compression fittings on plastic pipes, it is important to follow the manufacturer’s instructions and safety guidelines to ensure a safe and effective installation. Here are some key safety considerations:
- Follow the Manufacturer’s Instructions: The first and most important step is to carefully read and follow the manufacturer’s instructions for both the plastic pipe and the compression fitting. This will ensure that you are using the correct tools and techniques, and that you are not inadvertently damaging the pipe or fitting.
- Choose the Right Fitting: It is important to select the right compression fitting for the plastic pipe you are working with. Different types of plastic pipes may require different types of fittings, so be sure to check the manufacturer’s recommendations.
- Use Proper Tools: Make sure to use the correct tools for the job, and follow the manufacturer’s recommendations for torque and tightening procedures. Using the wrong tools or over-tightening can damage the pipe or fitting, leading to leaks or failures.
- Avoid Excessive Force: When installing the compression fitting, avoid applying excessive force or torque, as this can damage the plastic pipe or fitting. Use a gentle touch and tighten the fitting gradually, checking for leaks as you go.
- Check for Leaks: After installing the compression fitting, check for leaks by turning on the water supply and inspecting the connection. If you detect any leaks, stop using the fitting immediately and address the issue before continuing.
- Be Mindful of Heat: When working with plastic pipes and compression fittings, be mindful of the potential for heat to cause damage. Avoid using heat sources near the pipes or fittings, and use caution when soldering or brazing near plastic pipes.
- Wear Protective Gear: When working with plastic pipes and compression fittings, wear appropriate protective gear such as safety glasses, gloves, and a dust mask. This will protect you from potential hazards such as dust, debris, and sharp edges.
Alternatives for Compression Fittings
If you don’t want to use compression fittings on plastic pipes, there are other types of fittings you can use, depending on the specific application and the type of plastic pipe you are working with.
Here are some common alternatives:
Solvent Weld Fittings
These fittings are commonly used with PVC and ABS piping systems. They are designed to be glued onto the plastic pipe using a solvent-based adhesive. Solvent weld fittings are available in a variety of shapes and sizes, including tees, elbows, couplings, and adapters. They are often used in plumbing and drainage applications.
Threaded Fittings
These fittings have threads that allow them to be screwed onto the plastic pipe. They are commonly used in polypropylene and other thermoplastic piping systems. Threaded fittings are available in a variety of sizes and shapes, including tees, elbows, and adapters. They are often used in industrial and chemical processing applications.
Push-fit Fittings
These fittings are designed to be pushed onto the plastic pipe, creating a tight seal without the need for tools or adhesive. They are commonly used in PEX and other flexible plastic piping systems. Push-fit fittings are available in a variety of shapes and sizes, including tees, elbows, couplings, and adapters. They are often used in plumbing and heating applications.
Barbed Fittings
These fittings have a series of barbs that grip the plastic pipe, creating a secure connection. They are commonly used in irrigation and other low-pressure applications. Barbed fittings are available in a variety of sizes and shapes, including tees, elbows, and adapters.
How to Remove a Plumbing Compression Fitting
Removing a plumbing compression fitting might seem daunting, but with the right tools and steps, it’s quite simple. Here’s a step-by-step guide on how to remove a compression fitting.
First things first, before you start any work on the plumbing, it’s essential to turn off the water supply to the affected area. This will help you avoid any water leakage or damage. Once you’ve turned off the water supply, you can start removing the compression fitting.
The compression fitting consists of three parts – the compression nut, the compression ring, and the fitting itself. You need to loosen the compression nut to remove the compression fitting. You can use a wrench to turn it counterclockwise to loosen it.
Once the compression nut is loose, you should be able to slide the fitting off the pipe. If it doesn’t slide off easily, you can use pliers or a compression fitting removal tool to help you remove it.
After removing the fitting, remove the compression ring as well. You can use pliers or the same compression fitting removal tool to remove the ring. It’s essential to remove the compression ring carefully without damaging the pipe as you’ll need to reuse the same pipe.
The next step is to clean the pipe. Use sandpaper or a pipe-cleaning tool to clean any debris or rough edges from the pipe. It’s crucial to clean the pipe properly to ensure a secure connection with the new fitting.
If you’re reusing the same compression fitting, you’ll need to replace the compression ring with a new one. If you’re installing a new fitting, you can slide the compression ring onto the pipe, followed by the fitting. Then, tighten the compression nut onto the fitting using a wrench.
Finally, turn on the water supply, and check for any leaks. If there are no leaks, you have successfully removed and replaced the compression fitting. Congratulations!
Related Questions
How Tight Should Plastic Fittings Be?
The specific amount of torque required for plastic fittings depends on the size and type of fitting and the material it is being installed into. As a general guideline, it is recommended to hand-tighten the fitting first and then use a wrench to turn it an additional quarter to half a turn. This should provide enough pressure to form a secure seal without risking damage to the fitting or the material it is installed into.
Should I Use Teflon Tape On Compression Fittings?
Yes, you can use Teflon tape on compression fittings to ensure a proper seal. Teflon tape is commonly used as a sealant in plumbing applications and can help prevent leaks in threaded connections.
When using Teflon tape on compression fittings, wrap it in the same direction as the threads to prevent it from unravelling or getting caught in the connection. Apply the tape snugly around the male threads of the fitting, overlapping the edges slightly to ensure complete coverage.
Note that Teflon tape should not be used on compression fittings that have an integrated rubber or plastic O-ring or gasket. In these cases, the O-ring or gasket should provide a sufficient seal without the need for additional tape.
Can Plumbing Compression Fittings Be Reused?
Whether or not plumbing compression fittings can be reused depends on the type of fitting and the condition of the fitting and its components.
Compression fittings that use a brass or copper ferrule (a small ring-shaped component) can often be reused if the ferrule is in good condition and has not been over-tightened. However, if the ferrule is damaged or deformed, it should be replaced before reusing the fitting.
On the other hand, compression fittings that use a plastic or nylon ferrule are typically designed for single use only and should not be reused. This is because plastic or nylon ferrules can deform over time and lose their ability to create a tight seal.
Note that a compression fitting with a corroded or damaged pipe may not create a secure seal even if the ferrule is in good condition. In these cases, replacing both the fitting and the pipe is recommended to ensure proper functionality and safety.
Bottom Line
Compression fittings can be used on plastic pipes as long as the fittings are designed and rated for use with plastic pipes. Not all compression fittings are compatible with plastic pipes, so it is essential to ensure that the fittings are designed specifically for use with plastic pipes.
When using compression fittings on plastic pipes, following the manufacturer’s instructions carefully and ensuring that the fittings are installed correctly is important. Proper installation prevents leaks and ensures a secure connection between the fitting and the pipe.