PEX crimp, clamp, and expansion connections can all create reliable joints when the tubing, fitting, ring or sleeve, and installation tool are approved to work together. The right method depends on the tubing manufacturer’s approval, the fitting system, jobsite access, and the tools being used. Do not choose a connection method based on the PEX-A or PEX-B label alone.
How do PEX crimp, clamp, and expansion connections differ?
Crimp connections use a copper or approved metal crimp ring compressed around PEX tubing and a compatible insert fitting. The connection is made with a crimp tool and should be checked using the gauge specified for that system.
Clamp connections use a stainless-steel clamp around the tubing and a compatible insert fitting. The clamp is tightened with a clamp tool. Some insert fittings are approved for use with either crimp rings or stainless-steel clamps, but the rings, clamps, and installation tools themselves are different and should not be substituted for one another.
Expansion connections use an expansion tool to temporarily enlarge approved PEX tubing and, depending on the system, a compatible expansion ring. An approved expansion fitting is then inserted, and the tubing contracts around the fitting. Use only tubing, rings, fittings, and tools approved for the specific expansion system.
Can you use crimp or clamp fittings on PEX-A?
Often, yes, but approval varies by brand and product. Some PEX-A tubing is approved for crimp or clamp connections in addition to expansion connections. Always check the printing on the tubing, the product documentation, and the fitting manufacturer’s instructions before installation.
Can you use expansion fittings on PEX-B?
Sometimes, but only when the specific PEX-B tubing is approved for the expansion system being used. Do not assume all PEX-B tubing can be expanded. Confirm the tubing markings and manufacturer documentation before using an expansion fitting or tool.
How do you choose the right PEX connection method?
- Read the tubing markings. Confirm the tubing type, size, applicable standards, and approved connection methods.
- Match the complete system. Use compatible tubing, fittings, rings or clamps, and installation tools. A fitting that physically fits does not necessarily mean the combination is approved.
- Consider access and the job. Tool clearance, joint location, available working space, and installation requirements can affect which approved method is most practical.
- Follow manufacturer instructions. Installation steps, tool calibration, ring placement, and inspection requirements can vary between systems.
- Follow local requirements. Plumbing codes and project specifications may include additional requirements. Always follow applicable codes and approved product instructions.
Common mistakes to avoid
- Mixing tubing, fittings, rings, clamps, or tools without confirming compatibility.
- Assuming a connection method is approved simply because it works with another brand of PEX.
- Treating crimp rings and clamp rings as interchangeable.
- Skipping required gauges, tool calibration, inspections, or maintenance.
- Ignoring tubing markings or manufacturer installation instructions.
- Assuming all PEX-A or all PEX-B tubing uses the same connection methods.
For potable water applications, also confirm that the tubing and components are certified for that intended use. If you cannot verify compatibility or certification, check the product documentation or contact the manufacturer before installing the connection.
Shop PEX connection supplies
Browse our PEX crimp tools and PEX clamp tools to find the equipment you need for your project. Before purchasing, confirm that the tool, fitting, and connection method are approved for the specific PEX tubing being installed.
Frequently asked questions
Can the same PEX fittings be used for crimp and clamp connections?
Sometimes. Many insert or barb fittings are approved for use with either copper crimp rings or stainless-steel clamps. However, compatibility depends on the fitting manufacturer and system. The crimp rings, clamps, and installation tools are different and should not be substituted for one another.
Is expansion always the best connection for PEX-A?
Not necessarily. PEX-A may support multiple connection methods depending on the tubing brand and fitting system. Expansion is commonly associated with PEX-A, but crimp and clamp connections may also be approved. Always check the tubing markings and manufacturer instructions.
Can I mix PEX brands?
Do not assume components from different brands are compatible. Confirm that the exact tubing, fitting, ring or clamp, and installation tool combination is approved before making the connection.
