Plumbing Puzzle Solved: Is It Possible to Weld PEX and PVC?

Plumbing projects often involve connecting different types of pipes, and the question of whether you can glue PEX pipe to PVC pipe is a common one. In this blog post, we will explore the compatibility of these two materials and provide guidance on how to connect them using alternative methods.

Understanding PEX and PVC Pipes

PEX (Polyethylene Cross-linked) is a flexible, durable plastic pipe that is widely used in plumbing systems. It is resistant to corrosion, scale buildup, and freezing. PEX pipes can be connected using crimp rings, clamps, or expansion fittings.

PVC (Polyvinyl Chloride) is a rigid plastic pipe that is commonly used for drainage and sewer lines. It is strong, lightweight, and resistant to chemicals. PVC pipes are typically connected using solvent cement or mechanical fittings.

Can You Glue PEX Pipe to PVC Pipe?

No, you cannot glue PEX pipe to PVC pipe using traditional PVC glue. PEX is a polyethylene-based material, while PVC is a vinyl-based material. These two materials do not bond well with each other, and the glue will not create a strong or reliable connection.

Alternative Methods for Connecting PEX and PVC Pipes

While you cannot glue PEX pipe to PVC pipe directly, there are several alternative methods you can use to connect these two types of pipes:

1. Transition Fittings

Transition fittings are specially designed fittings that allow you to connect different types of pipes. They are available in various sizes and configurations to accommodate different pipe diameters and types. To connect PEX pipe to PVC pipe using a transition fitting, simply insert the PEX pipe into the PEX side of the fitting and the PVC pipe into the PVC side of the fitting. Tighten the nuts or screws on the fitting to secure the connection.

2. Mechanical Fittings

Mechanical fittings use compression or expansion to create a seal between the pipes. They are available in a variety of sizes and styles, including clamps, couplings, and unions. To connect PEX pipe to PVC pipe using a mechanical fitting, follow these steps:

1. Cut the PEX pipe and PVC pipe to the desired lengths.
2. Insert the PEX pipe into the PEX side of the fitting and the PVC pipe into the PVC side of the fitting.
3. Tighten the nuts or screws on the fitting to compress or expand the fitting around the pipes, creating a seal.

3. Solvent Weld Adapter

Solvent weld adapters are available that allow you to connect PEX pipe to PVC pipe using solvent cement. These adapters have a PEX connection on one end and a PVC connection on the other end. To use a solvent weld adapter, follow these steps:

1. Clean the ends of the PEX pipe and PVC pipe with a solvent cleaner.
2. Apply a thin layer of solvent cement to the ends of the PEX pipe and PVC pipe.
3. Insert the PEX pipe into the PEX side of the adapter and the PVC pipe into the PVC side of the adapter.
4. Hold the connection together for a few minutes to allow the solvent cement to set.

Which Method Should You Use?

The best method for connecting PEX pipe to PVC pipe depends on the specific application and the size of the pipes. Transition fittings are a good option for connecting large-diameter pipes, while mechanical fittings are suitable for smaller-diameter pipes. Solvent weld adapters are not recommended for use with PEX pipes, as they can damage the PEX material.

Wrap-Up

While you cannot glue PEX pipe to PVC pipe directly, there are several alternative methods you can use to connect these two types of pipes. By choosing the right method and following the proper steps, you can create a secure and reliable connection that will last for years to come.

Questions You May Have

1. What is the strongest way to connect PEX pipe to PVC pipe?

Transition fittings are generally the strongest method for connecting PEX pipe to PVC pipe. They provide a secure and leak-proof connection that can withstand high pressure and temperature.

2. Can I use a SharkBite fitting to connect PEX pipe to PVC pipe?

Yes, you can use a SharkBite fitting to connect PEX pipe to PVC pipe. SharkBite fittings are push-to-connect fittings that do not require any glue or tools. They are available in a variety of sizes and configurations to accommodate different pipe diameters and types.

3. What is the maximum temperature that a PEX-to-PVC connection can handle?

The maximum temperature that a PEX-to-PVC connection can handle depends on the type of fitting used. Transition fittings are typically rated for temperatures up to 200°F, while mechanical fittings are typically rated for temperatures up to 140°F. Solvent weld adapters are not recommended for use with PEX pipes, as they can damage the PEX material.