As a plumbing expert with extensive experience in the field, I can provide you with a detailed answer regarding the use of PEX fittings on polybutylene pipes.

Polybutylene (PB) is a type of plastic piping material that was widely used in the 1970s and 1980s for residential plumbing systems. However, it has since been largely phased out due to concerns over its durability and the potential for leaks and failures, particularly when exposed to certain chemicals found in some plumbing systems.

PEX, on the other hand, is a cross-linked polyethylene piping system that has become increasingly popular due to its flexibility, durability, and resistance to corrosion. It is a versatile material that can be used in a variety of plumbing applications.

When it comes to connecting PEX fittings to polybutylene pipes, it is important to note that these two materials are not directly compatible. This is because the properties of the materials and the way they expand and contract under different temperatures are different. Directly connecting PEX to polybutylene without a proper conversion can lead to leaks and potential failure of the plumbing system.

To address this issue, there are specialized conversion couplings available in the market, such as the SharkBite conversion coupling. This type of coupling is designed to connect polybutylene pipes to other types of piping materials, including PEX. The conversion coupling works by providing a transition from the polybutylene pipe to a copper tube size (CTS), which is a standard measurement used for various plumbing fittings.

Here is a step-by-step process on how to use a SharkBite conversion coupling to connect PEX fittings to polybutylene pipes:


1. Identify the Pipe Types: Ensure that you have correctly identified the polybutylene pipe and that you have the appropriate PEX fittings and a SharkBite conversion coupling.


2. Prepare the Polybutylene Pipe: Clean the end of the polybutylene pipe to remove any dirt or debris. You may need to cut the pipe to the correct length.


3. Apply the Conversion Coupling: Insert the end of the polybutylene pipe into the SharkBite conversion coupling until it is fully seated. The coupling should have a rubber seal that ensures a watertight connection.


4. Secure the Connection: Tighten the SharkBite conversion coupling according to the manufacturer's instructions. This may involve using a wrench or simply hand-tightening.


5. Connect the PEX Fittings: Once the polybutylene pipe is securely connected to the SharkBite conversion coupling, you can now proceed to connect your PEX fittings. Ensure that the PEX fittings are compatible with the copper tube size (CTS) provided by the coupling.


6. Test the Connection: After connecting the PEX fittings, it is crucial to test the entire system for leaks. This can be done by pressurizing the system and checking for any signs of leakage.

7.
Finalize the Installation: Once you have confirmed that there are no leaks, you can proceed to complete the rest of the plumbing installation.

By following these steps, you can successfully connect PEX fittings to polybutylene pipes using a SharkBite conversion coupling. This allows you to take advantage of the benefits of PEX piping while ensuring a secure and leak-free connection to the existing polybutylene system.

Remember, it is always recommended to consult with a licensed plumber or follow the manufacturer's instructions when working with plumbing systems. Proper installation and adherence to safety guidelines are essential to avoid any potential issues.

read more >>

The SharkBite conversion coupling will convert polybutylene to any copper tube size (CTS), such as copper, PEX, or CPVC. The pipe end can only be used on polybutylene pipe. ... You now have converted to copper tube size (CTS) and are free to use all available materials to complete repair or remodeling.read more >>