PEX (cross-linked polyethylene) piping systems are increasingly popular in modern plumbing due to their flexibility, corrosion resistance, and ease of installation. Among the various connection methods for PEX pipes, press technology offers an efficient and reliable option. This article will delve into the feasibility, compatibility, material characteristics, and installation details of using press fittings in PEX piping systems.
Compatibility of Press Fittings with PEX Pipes
PEX press fittings are components specifically designed for connecting PEX pipes. They typically come with pre-installed stainless steel press sleeves and require specialized PEX press tools for installation. Renowned brands like Viega offer a variety of PEX press fittings suitable for different pipe sizes and connection needs.
Regarding compatibility, the PEX press connection method is compatible with all types of PEX tubing (PEX-A, PEX-B, PEX-C). This means that regardless of the PEX pipe type used, a reliable connection can be achieved as long as the correct press tools are employed for installation. However, it is important to note that manufacturers usually only guarantee connections when their brand of tubing is used in conjunction with their fittings. Therefore, in practical applications, it is advisable to use pipes and fittings from the same brand to ensure system integrity and warranty validity.
Materials and Characteristics of Press Fittings
PEX press fittings are primarily available in two common materials: PolyAlloy and Bronze. Both materials are lead-free and suitable for potable water systems.
Bronze Fittings: Bronze, as a traditional material, has a long history of use and proven performance. Unlike some brass fittings that may suffer from dezincification, bronze contains no zinc, thus eliminating this issue and ensuring long-term stability and durability of the connection. While DZR (DeZincification Resistant) brass alloys and “ECO brass” have mitigated the dezincification problem to some extent, bronze remains a preferred choice for many professionals.
PolyAlloy Fittings: PolyAlloy is a relatively newer material in the market. Other than the material difference, PolyAlloy fittings are functionally similar to bronze fittings. Since plastic cannot be soldered, PEX press systems do not offer soldered transition adapters from plastic press to copper pipes/fittings.
Installation Features and Considerations
PEX press fittings are designed with ease of installation and reliability in mind:
Size Identification: To help installers identify fitting sizes and select the appropriate tools, press fittings often feature color-coded plastic sleeves at their base. For example, Viega’s fittings use green for 3/8″, yellow for 1/2″, blue for 3/4″, and orange for 1″.
Insertion Confirmation: A small hole on the press sleeve serves as a visual indicator, helping installers confirm that the pipe has been fully inserted into the fitting. This helps prevent connection failures due to insufficient pipe insertion.
Non-reusable: PEX press fittings are designed for single use. Once pressed, the fitting cannot be disassembled and reused.
FostaPEX Compatibility: PEX press fittings can also be used with FostaPEX tubing, but a FostaPEX prep tool is required to ensure a proper connection .
Conclusion
Using press fittings in PEX piping systems is entirely feasible and constitutes a reliable connection method. Their broad compatibility, durable material options, and user-friendly installation design make them a favored solution in both residential and commercial plumbing projects. Correctly selecting fittings, using specialized tools, and adhering to manufacturer’s installation guidelines are crucial for ensuring connection quality and system performance.