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LK PE-Xa Pipes - PEX Pipe Extrusion - LK Pex€¦ · LK PE-Xa pipes Production method The method...

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LK PE-Xa Pipes www.lkpex.se
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LK PE-Xa Pipes

www.lkpex.se

Lagerstedt & Krantz’s head office in Stockholm, Sweden

LK Pex production site in Ulricehamn, Sweden

LK Pex’ History

How it all startedLagerstedt & Krantz (LK) was founded in 1910 in Stockholm, Sweden. Today the business has grown into a group of sixteen companies with a presence in several countries and an annual turnover of approximately 100 million EUR. The main business sectors within the LK Group specialize in the manufacture, sales and distribution of products and systems for heating and plumbing as well as the marine industry.

Established in 1998, LK Pex was founded as a new company within the LK Group with the aim of manufacturing PE-Xa pipes to serve the needs of LK Systems, one of the largest under floor heating companies in Scandinavia. From its manu-facturing site in Ulricehamn (a small town 100 km east of Gothenburg), LK Pex is now producing pipes for customers throughout Europe and as far away as the USA and the Middle East.

The LK Pex Story So FarIn 1998 we started to develop our own unique production method of PE-Xa pipes using the latest technology available. Thanks to Mr Lennart Ågren, a world-wide well-reputed person in the field of PEX pipes who has been with the company since the beginning, we have the most competitive PE-Xa production in the world. Full manufacturing production commenced in January 2000 with customers all over the world.

Today we annually produce 80 million meters with a continuous growth of PE-Xa pipes, PE-RT pipes and cross linked inliners for flexible hoses. However, one benefit is universal through-out the range – the FLEXIBILITY of our pipes.

Developement in focusWe are always aiming to extending the dimension range and further developing the materials for new applications in assorted industries.

LK Pex has a well equipped laboratory for in-house control of our products to secure high quality for our customers.

Our world-class Development Department has several times developed excellent new products and techniques. Being first on the market is one of the reasons for LK Pex’ success.

Antioxidants

Mission and VisionOur mission is to supply and serve customers needs in various industries throughout the world with high quality service, pipes and hoses.

Our vision is to remain one of the most efficient pipe producers in the world, still with highest quality regarding flexibility, strength, service and reliable deliveries.

LK PE-Xa pipes

Production methodThe method used to cross link Polyethylene into PEX pipes determines the type; PE-Xa is cross linked with peroxide, PE-Xb by using silane and PE-Xc by electron beams. PE-Xa is the fastest growing production method in the world of the three. Cross linking of LK Pex pipes is initiated by peroxide radicals, meaning they are PE-Xa pipes.

For the production of LK PE-Xa pipes, IR light is used to form peroxide radicals. LK Pex have the longest experience and are also the largest PE-Xa pipe producer worldwide utilizing the new modern short wave IR technology for cross linking of the pipes.

In general, PE-Xb pipes have the highest density, followed by PE-Xc and PE-Xa. LK PE-Xa pipes have, due to a unique process an even lower density than conventional PE-Xa pipes.

Density of various PEX materialsPE-Xa is the only one step process, and also the only process where cross linking occurs at a temperature above melting point. The benefit of this is that the cross linking is evenly distributed in the pipe, as crystallites are melted when the cross linking takes place. This also lowers the density of the material, giving a more flexible pipe. LK PE-Xa pipes are among the most flexible PEX pipes on the market.

The Slinky toy and LK PE-Xa pipes have a lot in common. Formed like a tube the Slinky bends around itself amazingly narrow as it walks down the steps. The shape is round (not oval), meaning it never kinks although the bending radius is minimal. Still, as a tube it is very strong. In the LK PE-Xa pipes, the molecular chains are stretched out like fibers and oriented around the tubing just like the flat wire circles around the Slinky spring. This makes the tubing very flexible and kink-resistant and gives the pipe excellent strength.

No ovalization or kinking of pipe. Bending radius less than four times outer diameter

Molecular orientation around the pipe

When the pipe was tested according to ISO 9080; Bodycote Polymer, an independent test institute, classified the pipe as a PE-X 100 Material (MRS = 10 MPa)

International Approvals/CertificationsLK PE-Xa pipes have certifications from the most renowned institutes in Europe and USA.

The official test results on the LK PE-Xa pipes (above) were so good that the pipe was qualified as a ”PE-X 100 Mate-rial” (MRS=10 MPa), which is extremely unusual and clearly positive. A ”PE-X 100 Material” has higher pressure with standing properties than that required for high density PE-X. For this reason, Bodycote Polymer Test Institute asked if they could publish the results on their website.

Benefits with LK PE-Xa pipes

▫ Strength: Molecular orientation gives the LK PE-Xa pipe strength

▫ Excellent homogeneity: The material is thoroughly blended when extruded for a perfect homogeneity and antioxidant dispersion

▫ Good temperature behavior: The pipe can withstand temperatures down to – 100 °C and short term up to 110 °C

▫ High flexibility: Easy and ergonomic to install

▫ Kinking resistance: Because of the high flexibility of the LK PE-Xa pipe kinking resistance is excellent

▫ Thermal memory: If the pipe is “kinked” it can restore its form when being heated (> 133 °C)

▫ Chemical resistant: Improved ESCR (environmental stress cracking resistance) and resistant to several chemicals

▫ Crack propagation resistant: Stands scratches as the material is resistant to crack propagation

▫ Wear resistant: Excellent abrasion resistance

▫ Low friction: Low pressure drop and no risk of deposit sediments

▫ Electric isolated: Being a non-polar material, the PE-Xa pipes have excellent electric isolation properties

▫ UV stabilized: Apart from antioxidants to give the pipe long term stability, LK Pex also mix UV stabilizer into the raw material giving the LK PE-Xa pipes short term resistance to UV radiation

Material propertiesTypical values for material in LK PE-Xa pipes.

Property Value Test method

Degree of cross linking ≥ 70 % EN 579

Density 0.935 g/cm3 ISO 1183, method D

Thermal expansion coefficient 1,8 • 10-4 K-1 DIN 52328

Thermal conductivity < 0.4 W/m • K DIN 52612

Softening temperature > 130 °C DIN 53460

Elongation at break > 400 % ISO 6259

Tensile strength 25 MPa ISO 6259

Roughness factor 0.0005

Cross linking test

Service conditionsLK PE-Xa pipes for potable water are tested and approved to withstand a pressure of 10 bars at continuously 70 °C and peak temperatures at 95 °C for more than 50 years. Under floor heating pipes can withstand a pressure of 6 bars at continuously 70 °C for more than 50 years with peak temperatures of 95 °C. Furthermore, all pipes are in accordance with the EN ISO 15875 standard.

Application class

Design temperature,

TD (°C)

Time at TD

(years)

Tmax

(°C)

Time at Tmax

(years)

Tmal

(°C)

Time at Tmal

(h)

Typical field of

application

1a 60 49 80 1 95 100Hot water

supply (60 °C)

2a 70 49 80 1 95 100Hot water

supply (70 °C)

4b

20 2.5

70 2.5100 100

Under floor heating and low

temperature radiators

followed by

40 20

followed by

60 25

followed by (see next column) followed by (see next column)

5b

20 14

90 1100 100

High temperature

radiators

followed by

60 25

followed by

80 10

followed by (see next column) followed by (see next column)

a: A country may select either class 1 or class 2, to conform to its national regulations.b: Where more than one design temperature appears for any class, the times should be aggregated (e.g. the design temperature profile for 50 years in class 5 is 20 °C for 14 years followed by 60 °C for 25 years, 80 °C for 10 years, 90 °C for 1 year and 100 °C for 100 h).

Note: For values of TD, Tmax and Tmal in excess of those in this table, this standard does not apply.

Classification of service conditions (EN ISO 15875-1)

DimensionsLK PE-Xa pipes are primarily intended to be used in heating systems, for potable water and for secondary district heating installations and are also used for cooling and material transportation. The pipes are produced in more than 35 different dimensions, from 8 mm to 110 mm in outer diameter. The pipes are available in a various number of lengths, from 6 meters straight lengths to 1 000 meter coils – depending on dimension.

PN6 PN10 Inch-sizes SDR 9

8 x 1.0 10 x 1.8 3/8”

10 x 1.5 12 x 2.0

12 x 1.1 15 x 2.5 1/2”

14 x 2.0 16 x 2.2 5/8”

15 x 1.5 18 x 2.5 3/4”

16 x 1.5 20 x 2.8 1”

16 x 1.8 22 x 3.0 1 1/4”

16 x 2.0 25 x 3.5 1 1/2”

17 x 2.0 28 x 4.0

18 x 2.0 32 x 4.4

20 x 1.9 40 x 5.5

20 x 2.0 50 x 6.9

25 x 2.3 63 x 8.6

32 x 2.9

40 x 3.7

50 x 4.6

63 x 5.8

75 x 6.8

90 x 8.2

110 x 10.0

Dimensions produced by LK Pex

We supply our OEM customers with dimensions above. Other dimensions can be produced upon request.

Pipes are available as 1-layer (without oxygen barrier) or 3-, 4- and 5-layers.

Layer Description

1 Base pipe, PE-Xa

2 Adhesive

3 EVOH (oxygen barrier)

4 Adhesive

5 PE

Pipe propertiesPipes should be stored and installed protected from UV-light, as UV radiation has negative effect on long term properties of the LK PE-Xa pipes. The pipes are stabilized to resist UV radiation only for a short period of time

Heat emission from the pipes is dependent on both dimension of the pipe as well as difference in temperature (water – ambient air, ∆T), see figure. Heat loss of pipes with increased wall thickness is approximately 95 % of the one presented in the diagram

Pipes used for heating have a layer of EVOH to protect the water and heating system from oxygen. The oxygen diffusion through the pipe is significantly lower than the requirements in DIN 4726. The oxygen permeation through the pipe is regularly tested at MPA NRW, Materialprüfungsamt Nordrhein-Westfalen

Pipes used for potable water do not require an oxygen barrier

The hygienic properties of the LK PE-Xa pipe have been tested and approved with respect to TOC, taste and smell, turbidity, phenol and nitrogen migration plus a theoretical evaluation in accordance with EN 852-1, ISO 4120-1983, ISO 4594-1983, Danish Approval Rules (strictest in the world). The tests were performed at DTC and DTI

The flexibility of the LK PE-Xa pipes allows a minimum bending radius of 5 times of the outer diameter of the pipe for free pipes. If the pipe is hot bended and an inner support is used, a minimum bending radius of 3.5 times the outer diameter is possible

Heat emission loss of LK PE-Xa pipes

W/m 250

225

200

175

150

125

100

75

50

25

00 10 20 30 40 50 60 70 80 ΔΤ(K)

110x10,0 90x8,2

75x6,8

63x5,8

50x4,6

40x3,7

32x2,9

28x4,025x2,322x3,020x2,018x2,517x2,0

15x2,5

12x2,0

10x1,8

16x2,0

The figure below explains the relation between long term strength of a polymer pipe and density, temperature, cross linking and antioxidant system.

LOGARITMIC TIME

STR

ESS

Increased Density

IncreasedCross linking

ImprovedAntioxidantsystem

IncreasedTemperature

IncreasedTemperature

LK Pex PE-Xa pipes are tested and approved by well-reputed certification organs all over the worldLK Pex is certified with respect to Quality Management, Environmental Management and Occupational Health and Safety in accordance with ISO 9001:2008, ISO 14001:2004 and OHSAS 18001:2007 respectively

Factory Site

LK Pex AB Rönnåsgatan 4A Box 21 SE-523 38 Ulricehamn Sweden

Phone: +46 321 278 30 Fax: +46 321 278 39 E-mail: [email protected]: www.lkpex.se

Customer Service

Phone: +46 321 278 50 +46 321 278 64

Export Sales

Phone: +46 321 278 21

LK Pex is certified with respect to Quality Management, Environmental Management and Occupational Health and Safety in accordance with ISO 9001:2008, ISO 14001:2004 and OHSAS 18001:2007 respectively.


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