A press fitting for gas installations made from stainless steel

Press Fit Technology Explained

June 9, 2020
Generally much faster in terms of installation, press-fittings help complete the project up to three times faster than customary methods.

Press-fitting systems are now among the latest trend with installers, replacing more traditional fitting methods of the past. Thanks to this connection technology, no site assessments or hot works permits are needed, allowing the installers to get to work quickly and efficiently. The entire project is safer as well due to the absence of a naked flame, making it particularly suitable for retrofit projects as well as new buildings.

Press-fittings provide a reliable seal, reduce error, and when pressed correctly, are free of leaks. Generally, a press-fit is the fastening of two parts—in this case, inserting a pipe into a fitting by normal force, with the interference holding both parts in place. Each press fitting is equipped with an o-ring inserted into the bead. This is then pressed together in an exact, easy, repeatable, and reliable process with a hydraulic pressing tool, making the connection tight. Different o-rings are used for drinking water, gas or other high-temperature applications and are also suitable for various industrial purposes.

Even though the pressing process is relatively simple, suppliers such as SANHA provide technical seminars or on-site training and certification for installers switching to the press-fit technique or in need of additional personal training. These include topics such as the physics behind press-fit technology, standards and norms, pipework design considerations to prevent for example stagnation or the advantages of different materials such as stainless steel, copper or multi-layer pipes used in press connections (but can expand on any content required).

Press-Fit Is Flame Free, Reliable, Faster, and More Practical

In the past, making a leak-tight plumbing joint required the use of fittings, solder, a blow torch, and a skilled and qualified plumber. Other tradespeople relied on brazing or welding. While these techniques still have their place in very large pipework or specialized areas such as medical gases, this could lead to dry joints, cracking or other solder-related problems. With press fittings, the sealing material and components are combined, and the heat source replaced by a hydraulic pressing tool.

When used correctly, a permanent connection is formed fast and securely and provides installers with a reliable, repeatable installation technology. Even more importantly, the tightness of the connection becomes partially the responsibility of the manufacturer of the piping system, not the installer. So not only is it quicker and more practical but the risks associated with making secure and reliable connections are significantly reduced for installers.

Press-Fit: A Solution for (Just About) Every Application

On the surface, the technology looks very simple—which is the sign of a good system—but the details require significant investment and resources. For example, when SANHA developed a new press-fit system, comprising of lead-free Silicon Bronze (CuSi) optimally suited for drinking water installations, it was necessary to develop a technology for the analysis of the crystalline grain structure in the raw material and to invest significantly in a completely new manufacturing process, replacing traditional machinery.

Today, the market offers a wide range of pipes and press fittings in many dimensions, providing an inherently reliable, solder and lead-free solution that delivers the safety and design flexibility needed for a wide range of applications across a multitude of industries, from residential and commercial buildings, hospitals, hotels, or even shipbuilding and other industrial applications. SANHA has over 50 years in the manufacturing of press-fit systems and today offers nearly all shapes such as elbows, reductions, couplings, tees or wall-mounting plates in dimensions 12 to 168 mm (depending on the required material and series).