PEX (cross-linked polyethylene) has become a game-changer in modern plumbing, offering flexibility, durability and cost savings. From residential water supply lines and radiant floor heating to large-scale commercial systems and retrofits, PEX is trusted for its ease of installation, corrosion resistance and ability to withstand extreme conditions. Whether you’re tackling a new build, upgrading aging pipes or designing efficient heating solutions, PEX delivers versatility and performance for projects of all sizes.

Why Fittings and Valves Matter

After deciding on PEX for your project, the next key step is selecting appropriate fittings and valves. These components are essential for connecting lengths of PEX, controlling water flow and ensuring a secure, leak-free system. Whether you're working with PEX-A or PEX-B, understanding the range of available fittings and valve options will help you maximize the reliability and efficiency of your installation. 

Types of PEX Fittings

When working with PEX-A and PEX-B piping, four types of fittings are commonly used, each with its own strengths and ideal applications:

Crimp Fittings

• Made of durable polysulfone polymer and secured with copper rings, crimp fittings are the most widespread and suitable for a variety of systems, though they require careful installation and can restrict flow. 

Expansion Fittings 

• Crafted from polymer or lead-free brass, expansion fittings allow for movement within the system but demand skilled labor and precise alignment. 

Push-Fit Fittings

• Offers quick, tool-free installation, making them popular for DIY projects, but their application range and compatibility are limited, and improper installation can lead to errors. 

Polymer Press Fittings

• These fittings deliver fast, permanent connections with minimal labor and long-term reliability. Viega’s PureFlow® Polymer Press Fittings feature advanced Radel® R material and stainless steel sleeves. 

Choosing the Right Valves

Valves are an essential component of any PEX plumbing system, providing critical control and flexibility, much like fittings provide reliable connections. There is a range of valves designed to meet the demands of various PEX applications:

Isolation Valves

• Widely used to stop water flow to a specific section without interrupting service to the entire system, making them ideal for manifold isolation, branch takeoffs and equipment connections. 

Supply Stop Valves 

• Installed at the point of use, such as under sinks or behind toilets, and allow for fixture-specific shutoff during maintenance.

Isolation + Transition Valves

• Unique to Viega, isolation + transition valves combine shutoff capability with the ability to connect copper to PEX, simplifying remodels and hybrid systems.

Viega offers valve options in different sizes and connection types, including PureFlow Press, PureFlow Crimp and PureFlow Poly/Alloy, to ensure every part of your PEX system is both accessible and secure.

Learn More

For deeper insights into PEX formulations, connection techniques and system design, check out the Plumber Magazine webinar featuring Viega Product Managers Alex Warren and Ryan Bennett: Everything You Need to Know About PEX Fittings and Valves