Comparing Pressing vs. Cold Expansion

Share Article

No matter the project, secure plumbing connections are crucial for residential and commercial jobs. Maximizing safety, efficiency and reliability not only ensures a quality output but also keeps your bottom line profitable. That’s why choosing the right method of joining pipe or tubing for the job is so important.

Viega press fittings enable fast, flameless, consistent connections in seconds, making it a whole-home solution for residential and commercial jobs of all sizes. Another commonly used, effective method for connecting PEX is cold expansion. When deciding which option makes sense for the job, it’s important to have a thorough understanding of each.

Read on for everything you need to know about pressing and cold expansion.

How Pressing Works

To make a quality press connection, you need a press tool and a press fitting. The connection is made when the press tool applies up to 5400 pounds of force to create a watertight seal between the fitting and the tubing.

Begin with a square cut of the PEX tubing for measurement. Then, place the fitting onto the tubing ensuring that your tubing is visible through the indicator windows on the stainless-steel press sleeve. Place the press tool onto the fitting against the tool locator ring and pull the trigger on a battery tool or squeeze the handles on a hand tool depending on size. Now you have a secure connection.

Advantages of Pressing

One of the best things about pressing is the consistent quality. Regardless of external conditions — including low temperatures — this method for connecting tubing ensures a quality result time after time. This means less labor, easier training and faster work pace, all while delivering strong, secure connections. This consistency minimizes risk and callbacks.

While press is a great option for connecting tubing or pipe, some professionals are hesitant to adopt it due to the initial expense of purchasing a press tool and a lack of press education in the industry. However, pressing enables you to tackle more jobs in a fraction of the time, ultimately offering a major return on investment. Additionally, the learning period for press is substantially shorter than training on traditional methods, meaning apprentices can start helping on the job faster. If you’re looking to get into pressing but aren’t sure where to start, reach out to a member of our team.

Understanding Cold Expansion

Cold expansion is a method of connecting PEX where an expansion ring is placed over the end of the tubing, the tubing end is then expanded to fit over a fitting and then the expansion ring and tubing contract to form a tight seal. This process involves a square cut of the tubing to the determined length, using an expander tool to enlarge the tubing end, inserting the fitting into the expanded tubing end and allowing the pipe to contract around the fitting.

Both processes create a strong, secure connection and offer versatility with different applications, sizes and materials. However, cold expansion takes longer, requires more skill and is more prone to material fatigue over time.

Going Toe to Toe

Below is a point-by-point comparison of pressing vs. cold expansion.

Installation Time:

Pressing: Typically faster, reducing labor costs and project timelines. Ready for pressure testing immediately.

Cold Expansion: Slower process due to the need for material contraction. Additional time is often needed before pressure testing as the tubing increases in size and varies by ambient temperature.

Reliability and Durability:

Pressing: Consistent, reliable connections.

Cold Expansion: Strong, durable connections but potential for material fatigue.

Skill Requirements:

Pressing: Shorter time to learn. Much faster on the jobsite.

Cold Expansion: Requires more training and experience.

Check out pressing vs. cold expansion in this side-by-side comparison video.

Making the Right Choice for the Job

Now that you understand the main differences between pressing and cold expansion, you can make an informed decision on your next project. If you still have questions, don’t hesitate to reach out to our engineering services team.