Flexible Systems – PEX-Flex

Only a professionally manufactured insulated pipe will maximize the efficiency of an outdoor wood furnace system by keeping heat losses to a minimum. By effectively heating the house (not the ground), less fuel is required, less wood is burned producing less emissions. Whatever your budget, you simply can't afford not to install PEX-Flex! Supplied in coils, this 2-in1 (supply and return bundled together) pipe is economical, simple to install and highly effective even in harsh soil conditions.

PEX-Flex is “self-compensating” with respect to expansion and contraction … just uncoil and snake into trench, then backfill. The pipe installs quickly and easily without solvent welding, special tools or heavy equipment resulting in a lower installed cost when compared to other insulating methods. No drainage tile, gravel fill or deep/wide trench required. PEX-Flex can be shallow buried even in high water table areas. The flexible nature of coiled PEX-Flex all but eliminates the need for joints, elbows and fittings making it a true seamless pipe system.

The PEX-Flex carrier pipe is made of plastic cross linked polyethylene (PEX) with EVAL coating which keeps oxygen from penetrating the pipe wall. The PEX is surrounded by a factory applied layer of closed cell, eco-friendly polyurethane foam – the best insulation material on the market. The whole package is encased in a tough but flexible extruded polyethylene jacket with UV stabilizer.

The pipe system is bonded … meaning the carrier pipe(s), insulation and jacket are mechanically linked to one another and move collectively during expansion/contraction. This also isolates a moisture problem to damaged area should the jacket be punctured … water cannot migrate through entire pipe system.

All PEX-Flex pipe comes equipped with a “smart” membrane between the outer casing and the insulation. This leak proof diffusion barrier prevents (cyclopentane) gas in the foam from escaping through the jacket and being replaced by atmospheric air which has inferior insulating properties – a process called “aging”. This keeps the operating performance high throughout the entire service life of the pipe.

PEX-Flex is manufactured by Logstor of Denmark, the world’s largest producer of pre-insulated pipe systems employing over 1400 people in 9 production facilities. Logstor has over 30 years experience of pre-insulating flexible PEX tubing. Urecon Ltd. distributes Logstor products throughout Canada and the US.

The Payback:

Installing PEX-Flex actually pays for itself over time*, and you're also helping to do your part to reduce emissions.

The expected yearly savings is approximately 1 ½ cords of wood based on the following assumptions:

• An average cord of wood yields 24 million BTU's (7 MW/hr).
• The trench from the furnace to the building(s) is approximately 30 m (100 ft) long.
• The payback is based on a comparison to bare or poorly insulated piping systems. These inferior systems may be the result of using materials with insufficient insulating properties, inadequate insulation thickness, or may simply be insulation that absorbed moisture due to water ingress through the jacket or joints.

* Individual payback times will vary relative to the severity and length of the heating season.

Using 2 x 32 mm x 110 mm OD (2 x 1 in x 4.3 OD) with following operating parameters:

• Supply temperature: 82°C (180°F)
• Soil temperature: 0°C (32°F)

Flow		Distance
GPM (US)	1/sec	30 m (100 ft)	46 m (150 ft)
3	0.19	81.4°C (178.5°F)	81.0°C (177.8°F)
5	0.32	81.7°C (179.1°F)	81.5°C (178.7°F)
10	0.63	81.9°C (179.5°F)	81.8°C (179.3°F)

Dual PEX-Flex Dimensions

Nominal pipe size	Carrier pipe OD	Carrier pipe ID	Carrier pipe wall thickness	Jacket pipe OD	Standard/ Maximum coil lengths*	Minimum bending radius	Weight
in	in (mm)	in (mm)	in (mm)	in (mm)	ft (m)	ft (m)	lb/ft (kg/m)
2 x ¾	2 x 0.98 (2 x 25)	0.784 (20)	0.098 (2.5)	4.3 (110)	328/ 656 (100/200)	3.5 ( 1.1)	1.4 (2.1)
2 x 1	2 x 1.26 (2 x 32)	1.032 (26.2)	0.114 (2.9)	4.3 (110)	567/1,134 (173/246)	3.5 (1.1)	1.5 (2.2)
2 x 1¼	2 x 1.57 (2 x 40)	1.280 (32.6)	0.145 (3.7)	4.9 (125)	328/ 656 (100/200)	4.0 (1.2)	1.8 (2.7)
2 x 1 ½	2 x 1.97 (2 x 50)	1.608 (40.8)	0.181 (4.6)	6.3 (160)	328 (100)	5.2 (1.6)	2.8 (4.1)

In bold is dual 1” PEX-Flex … most commonly used size for OWF applications (note the ID of the carrier pipe is 1.03” which is considerable larger than other ASTM pipes).

* Pipe can also be supplied to exact length required. Maximum lengths are special order
n.b.: All sizes are metric, not IPS nor CTS sizes; imperial adapters are supplied as required.

PEX-Flex Temperature and Pressure

Pipe size	Max. temperature	Max. pressure
in (mm)	Fahrenheit (Celsius)	P.S.I. (bar)
¾ - 1½ (20 - 50)	203 (95)*	87 (6)

*Refer to detailed PEX-Flex product specification at www.pexflex.net for temperature and pressure considerations.

Other Applications

Millions of feet of PEX-Flex have been installed in industrial, commercial and residential hydronic related pipe systems around the world. The pipe is used wherever energy savings are required by keeping overall heat losses (or gains) to a minimum. Typical applications include ice/snow melt systems; chilled water distribution; hot water district energy projects; chemical feed; industrial process piping and even solar heating.

Flexible steel pipe (STEEL-Flex) is also available in coils for projects requiring higher temperature thresholds. See our Flexible Systems brochure for more information.

Ice/Snow Melt Systems

Use PEX-Flex to run warm water from the heat source to the pad without losing heat.

Chilled Water Distribution

Use PEX-Flex to distribute centrally chilled water for air conditioning … often without joints or fittings. The highly efficient polyurethane insulation reduces heat gain from the warm soil (or ambient air temperature) greatly increasing system efficiency.

Hot Water District Energy

Use PEX-Flex to move around hot water in campus style systems … often without joints or fittings. Also ideally suited for steam condensate return.

Chemical Feed / Industrial Process Piping

Use PEX-Flex for transfer of chemicals or general process piping. Typically, joints and fittings are eliminated reducing worry of leakage … saving money when compared to traditional containment piping.

Ordering Information

PEX-Flex can by purchased from distributors throughout Canada and the US. Click here for more information.