PEX Tubing

Table 1. Connection systems compatibility chart – by Type:

	Crimp System	Clamp System	Push-To-Connect System	Press System	Expansion System	Compression Fittings
Barrier PEX	Yes	Yes	Yes	Yes	No	No
Non-Barrier PEX	Yes	Yes	Yes	Yes	No	No
PEX-AL-PEX	No	No	No	No	No	Yes

Crimp and clamp systems utilize brass or poly crimp style fittings and copper crimp rings or stainless steel cinch clamps. These are the most common and widely available connection systems in the USA.
Push-to-connect fittings (also known as Push-Fit or Quick-Connect) are removable type fittings which do not require a tool. Common brands include SharkBite (Cash Acme), TecTite (Elkhart), Pro-Connect (Webstone Valves) and others.
Press system uses stainless steel sleeves and a special press tool. Originally developed by Viega.
Expansion system is a proprietary connection system from Uponor (formerly Wirsbo).
Compression fittings consist of an insert, a split compression ring and a compression nut. This method requires adjustable pliers or crescent wrench to complete the connection.

Table 2. Connection systems compatibility chart – by Brand:

Everhot PEX	Compatible with (Mfr/Brand)	Not compatible with
Barrier & Non-Barrier PEX pipe	Zurn (ZurnPEX) Watts (RadiantPEX, RadiantPEX+, WaterPEX) Viega (ViegaPEX) Nibco (DuraPEX, BarrierPEX) Cash Acme (Sharkbite) Sioux Chief and most others.	Uponor (ProPEX) Rehau (Everloc) Watts (Onyx) Other proprietary systems
PEX-AL-PEX	Watts (Radiant PEX-AL) Uponor (MultiCor) Viega (FostaPEX)	Other proprietary systems

*Only a few, most common brand names are listed here. In general, Everhot PEX tubing will work with all non-proprietary brands using connection systems from Table 1. This also includes fittings, rings and tools sold at home improvement stores and local plumbing supply houses.

All standards, approvals and certifications below are for Everhot PEX products only.

Certifications & Approvals

Type	Heating Applications	Plumbing (Potable Water) Applications
Oxygen Barrier PEX	Yes - NSF/ANSI 14, nsf-rfh	No
Non-Barrier PEX	Yes*	Yes - NSF/ANSI 61 Annex G (nsf-pw-g), NSF/ANSI 372, NSF P171, AB1953
PEX-AL-PEX	Yes - NSF/ANSI 14, nsf-rfh	Yes - NSF/ANSI 61 Annex G (nsf-pw-g), NSF/ANSI 372, NSF P171, AB1953

*For open-loop systems only

Everhot Non-Barrier PEX piping is fully in compliance with 2014 SDWA “lead-free” regulations and is approved for residential and commercial potable water use, including municipal chlorinated water.
Everhot Oxygen Barrier PEX tubing is approved for heating applications only.
All Everhot PEX is certified to the UPC (Uniform Plumbing Code).

Standards

Oxygen Barrier PEX	ASTM F876/F877, CSA B137.5, DIN 4726
Non-Barrier PEX	ASTM F876/F877/F2023, CSA B137.5
PEX-AL-PEX	ASTM F1281, CSA B137.10

Q: What’s the difference between oxygen barrier and non-barrier PEX?
A: Oxygen barrier type PEX pipe has an external polymer coating called EVOH or “oxygen diffusion barrier” and it’s the type used for all standard closed loop heating applications, including floor heating, baseboard/radiator heating and snow melting. Non-barrier PEX has no additional coatings and is the type used for hot and cold water plumbing applications, as well as for open-loop heating systems.

Q: What’s the difference between open and closed loop systems?
A: A closed loop heating system contains water which circulates in a closed loop without mixing with fresh water or being exposed to the atmosphere. In a closed loop system, water is heated by a boiler (or similar), pumped to the floor heating system (or baseboards/radiators), then returns back to the boiler and the cycle repeats. Such systems often contain cast iron parts (boilers’ heating elements, pumps, etc.) and therefore would require PEX with O2 barrier.
An open loop heating system often utilizes the domestic hot water from a water heater or a storage tank and therefore has high oxygen content, which would require that the system’s components are either stainless steel, bronze or brass. Such systems do not require an O2 barrier and can use the non-barrier type PEX.

Q: Can I use PEX for solar applications?
A: No. Temperatures in solar systems often far exceed the 180°F rating of the PEX tube and would require either copper or corrugated steel pipes.

Q: Which size PEX tubing should I use?
A: For residential radiant floor heat installations, 1/2" PEX tubing is most common. For commercial, sizes up to 3/4" (and even 1" in some cases) can be used depending on the project size. For baseboards, 5/8" or 3/4" PEX are recommended, although very small baseboards can be fed with 1/2" PEX lines. For cast iron and aluminum radiators, 3/4" PEX is a standard size.
In small to mid size residential plumbing 3/4" PEX is used for mains and 1/2" for feeding water to the fixtures. In larger size homes, 1" size is sometimes used for main water lines.

Q: What’s the recommended spacing of PEX in a floor heating system?
A: When attaching to the subfloor between the joists with 16" OC spacing, 1/2" PEX is spaced at ~8" apart. For most other installations, including thin slabs over plywood, basements and structural (wire mesh or rebar reinforced) concrete slabs, the spacing is usually 10-12". The numbers above are typical for well insulated structures and may vary depending on local climate and temperature of water in the heating system.

Q: Does PEX color make a difference?
A: No. Tubing comes in different colors to help distinguish between hot and cold water lines with red and blue colored pipes respectively.

Q: Can I use Everhot PEX pipe with a different brand tools and fittings?
A: Yes, Everhot PEX tubing is compatible with majority of the tool and fitting brands sold in the US, including Watts, Viega, Nibco, Zurn and many others. See “Connection Systems” tab for compatibility details.

Q: Can PEX pipe be used for installation of an outdoor wood boiler or furnace?
A: Yes. 1" oxygen barrier PEX is most common for the job. For non-pressurized boilers, PEX piping without O2 barrier can be used.