Top Questions

What is an Uponor PEX plumbing system?
Uponor PEX plumbing systems for residential and commercial applications use crosslinked polyethylene (PEX) tubing instead of metal piping to distribute the water. PEX tubing is clean, non-toxic and extremely durable. The flexible nature of this tubing is gaining popularity with plumbers for both new construction and retrofit applications.


How long has Uponor PEX been used in plumbing systems?
Uponor PEX tubing has been used worldwide in plumbing and radiant heating systems for more than 30 years, longer than any other flexible system on the market.


Why is an Uponor PEX plumbing system a better choice for plumbing than copper?
First of all, it's a clean and quiet water distribution system. Additionally, Uponor’s plumbing system features Uponor AquaPEX® tubing, which is corrosion resistant. Aggressive water and soil, common across the United States, is not kind to copper plumbing and pinhole leaks can occur in copper as a result of these aggressive conditions. Additionally, An Uponor PEX plumbing system is quiet. No more singing pipes and water hammer typically heard with metal plumbing systems.


What’s the difference between PEX and CPVC?
Crosslinked polyethylene (PEX) and chlorinated polyvinyl chloride (CPVC) are both used for plumbing systems. The PEX manufacturing process chemically joins individual polyethylene molecules through an extrusion process to create a highly flexible tubing product. With CPVC, the manufacturing process starts with PVC resin and adds additional chlorine molecules, which creates a much more rigid tubing product. While both products are listed to their own respective ASTM standards for use in plumbing systems, PEX provides superior features, installation characteristics and longevity. For example, PEX systems offer:

• Reliable, visual connections
• No dry-fitting concerns
• Flexibility, fewer required fittings
• Quick and simple fitting connections
• Safe air testing
• No messy cements or solvents


Has Uponor PEX tubing undergone extensive testing?
Yes, Uponor PEX has undergone 35 years of rigorous testing. In 1973, Uponor (then Wirsbo), submitted PEX tubing samples to an independent laboratory. For three decades, these samples underwent continuous hydrostatic tests at extreme temperatures and pressures — up to 203åF and 239 pounds per square inch. When the 30-year life cycle tests were concluded recently, not a single piece of Uponor PEX had experienced any breakdown or failure.


Is an Uponor PEX plumbing system more expensive than the alternatives?
An Uponor PEX plumbing system is a very cost-competitive plumbing system when compared with other systems.


What is a ProPEX® connection?
Uponor’s unique ProPEX® connection method capitalizes on the shape memory of Uponor PEX-a tubing. ProPEX connections require the use of one simple tool to make fast, strong, solid connections that hold tight in strength tests with up to 1,000 pounds of force, without the use of torches, glues, solvents or gauges. And, the best part of all, ProPEX connections cannot be dry fit, so there is never a question whether the fitting is made.


Is the same PEX tubing used for both PEX plumbing and radiant floor heating systems?
Uponor offers two types of PEX tubing — Uponor AquaPEX® and Wirsbo hePEX™ tubing. Uponor AquaPEX is used in plumbing and in radiant systems where ferrous components are protected. Typically, Wirsbo hePEX is used for radiant floor heating as it contains an additional layer on the tubing which acts as a barrier and reduces the amount of oxygen entering into the heating system.


What’s the bend radius of PEX?
The bend radius is six times the outside diameter of the tubing.


Is Uponor PEX chlorine-resistant?
In recent years, ASTM F876 and ASTM F877 have been refined to incorporate benchmarks for chlorine resistance. Under certain conditions, a high concentration of chlorine can contribute to the oxidation of plastics. This, in turn, can affect service life. The upgraded ASTM standards provide an additional level of assurance that PEX tubing manufactured to these standards can withstand the potential oxidative effects of heavily chlorinated water.

Graywater Systems

How do graywater systems work?
In a graywater system, water is captured from sinks and showers into a holding tank where it goes through a filtering process. Then, specially designated purple tubing — the industry standard color for reclaimed water systems — distributes the filtered, reclaimed water from the holding tank out to laundry, toilets and irrigation systems.


What is the cost to add a graywater (reclaimed water) distribution system?
The cost can vary by region and building size, however, adding a dual potable/reclaimed water plumbing system can add minimal and sometimes even less cost compared to traditional plumbing systems.


Does a reclaimed water distribution system need a separate storage tank?
It depends on the application. While all reclaimed water systems require a filter tank to capture and sanitize the reclaimed water, the requirement for a separate storage tank depends on the specific plumbing application.


Can using AquaPEX Reclaimed Water tubing help meet LEED® or National Green Building Standard™ points?
Depending on your application, using AquaPEX Reclaimed Water tubing in a graywater system may help earn LEED® or National Green Building Standard™ points. (For further information, refer to or

Lead-free Systems

Why is Uponor offering lead-free brass transition fittings and valves?
Uponor is responding to recent proposed and approved lead-level and lead-free legislation from states such as California and Vermont. For example, California’s lead-free legislation (AB1953) states that all metallic fittings, fixtures and any material that conveys potable tap (drinking) water must meet lead-level criteria at or below 0.25% by composition. In addition, these lead-free brass fittings also exceed the United States Safe Drinking Water Act.


When is lead-level legislation set to take effect?
California and Vermont have already approved their proposed lead-free legislation, which took effect Jan. 1, 2010. Once a state’s legislation is approved and takes effect, all suppliers of metallic potable water components must prove their products meet the lead-level criteria by complying with the minimum requirement from the National Sanitation Foundation (NSF) and displaying the NSF us-pw-G markings.


What lead-free products does Uponor offer?
Uponor offers a comprehensive line of sweat fittings, threaded fittings, stub-outs, valves and wall boxes that can plumb a building with up to 2" inlet. Combining these transition fittings with our PEX tubing, extensive EP offering and ProPEX Out-of-the-Wall support system offers the industry’s first complete lead-free plumbing system from inlet to faucet.


Does the lead-free requirement affect Uponor’s PEX tubing or EP fittings?
No, Uponor’s PEX tubing and EP fittings contain no lead-level concerns.


Are Uponor lead-free brass fittings approved for direct burial in soil?
Yes, these fittings are approved for direct burial in soil and also replace our DZR brass fitting offering.

Pre-insulated Systems

What kind of cost savings does Pre-insulated AquaPEX offer?
On average, Uponor Pre-insulated AquaPEX saves approximately 37% over the two-step installation and insulation method.*
*Source: RS Means Construction Data


Can you use Pre-insulated AquaPEX in a plenum?
Pre-insulated tubing is not currently listed for installation in a plenum. Uponor is in the process of evaluating the product in this application.


Can you bury Pre-insulated AquaPEX?
Yes, provided the tubing is buried in an area away from contact with groundwater. Although the water will not compromise the integrity of the AquaPEX tubing or insulation, it will have a detrimental effect on the insulating value of the insulation.


Where can I use Pre-insulated AquaPEX?
Pre-insulated AquaPEX can be used in all areas of a potable water system.


Are there any accessories or guidelines for insulating connections (tees, ells, etc.) in conjunction with Pre-insulated AquaPEX?
The insulation can be pulled over the expanded ProPEX® Ring leaving only the fitting body un-insulated. Uponor does not offer insulation kits for the fittings; however, insulation kits are available in the industry if needed for your specific application.

Codes and Standards

What are the Uponor PEX standards?
Uponor PEX and associated fittings are manufactured to the following standards:
• ASTM F876 “Standard Specification for Cross-linked Polyethylene (PEX) Tubing”
• ASTM F877 “Standard Specification for Cross-linked Polyethylene (PEX) Plastic Hot and Cold Water Distribution Systems”
• ASTM F1960 “Standard Specifications for Cold Expansion Fittings with PEX Reinforcing Rings for use with Cross-linked Polyethylene (PEX) Tubing”
• ASTM F2080 “Standard Specifications for Cold Expansion Fittings with Metal Compression Sleeves for Cross-linked Polyethylene (PEX) Tubing”
• CSA B137.5 Thermoplastic Pressure Piping Compendium
Additional standards for Uponor AquaPEX tubing and associated fittings include:
• ANSI/NSF Standard 14 “Plastics Piping System Components and Related Materials”
• ANSI/NSF Standard 61 “Drinking Water System Components — Health Effects”
• UL 1821 “Standard for Safety for Thermoplastic Sprinkler Pipe and Fittings for Fire Protection Service” (½" Uponor AquaPEX® only)


What temperature and pressure ratings does Uponor PEX carry?
Uponor PEX carries the following hydrostatic temperature and pressure ratings:
• 200°F at 80 psi (93.3°C at 5.51 bar)
• 180°F at 100 psi (82.2°C at 6.89 bar)
• 120°F at 130 psi (49°C at 9 bar) (½" Uponor AquaPEX® tubing only)
• 73.4°F at 160 psi (23°C at 11 bar)


What code approvals does Uponor AquaPEX tubing have?
Uponor AquaPEX® tubing is approved in the following codes:
• NPC of Canada
• NBC of Canada


What listings does Uponor AquaPEX tubing have?
Uponor AquaPEX® tubing has the following listings:


What fire-rated assemblies does Uponor AquaPEX tubing have?
• G573 – Two-hour Hambro floor/ceiling assembly
• K913 – Two-hour concrete floor/ceiling assembly
• L557 – One-hour wood frame floor/ceiling assembly
• U372 – One-hour wood frame wall assembly
• V444 – One-hour steel stud wall assembly


What is the Warnock Hersey Plenum Rating for Uponor AquaPEX?
• 25 flame spread/50 smoke developed (plenum rated) to ASTM E84:
o ½" and ¾" with spacing of 18" between each run of tubing
o 1" through 2" when insulated with ½" fiberglass insulation
• CAN/ULC S102.2:
o ½" through 1" with spacing of 18" between each run of tubing
o 1¼" through 2" when insulated with ½" fiberglass insulation


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