Preinsulated system for temperatures above 145°C

Posted in Production range

Pre-insulated piping system for temperatures above 145°C is designed as so called sliding system. The carrier pipe expands within insulation without jacket moving in the ground. Expansion is absorbed by bends end expansion joints. The system can be installed above or under the ground.

The design of the sliding system is technically demanding, please consult with us any technical queries. 

 
Predizolovaný systém - para
 

This system is used for distribution:

  •          steam
  •          any media with temperature above 145°C up to 300°C

 

Service pipes

Welded steel pipes  P235GH EN 10217-2 , EN 10217-5 (DIN 1626), or seamless steel pipes P235GH according toEN 10216-2 (DIN 1629).

Dimension standard: EN 10217-1 (DIN 2448)  
Material: P235GH (St 37.0)
Certificate: EN 10204 – 3.1 B
Tests: non destructive
Bevels: DIN 2559/22
Lengths: 6 000 mm, or 12 000 mm

 

Density 7850 kg/m3
Elasticity 206 000 N/mm2
Characteristic stress 225 N/mm2
Strength tensile 350 N/mm2
Thermal conductivity 46 - 54,5 W/mK
Thermal extensibility 0,12 . 10-4K-1

 

Mineral wool

The mineral wool is used in a form of compressed, or grained shaped blocks:

Product  NOBASIL PVT 
Compression  strength  50 kPa
Thermal conductivity < 0,040 W/(m K)
Permanent thermal conductivity 230°C
Technical delivery conditions: PN 117 - 72 - 87
   
Product  RBP 18  
Density 170 kg/ m3 ± 10%
Thermal conductivity < 0,044 W/(m K)
Permanent thermal resistivity 750°C
Technical delivery conditions: DIN 181 65
   
Centringable lamellar segments LSP  
Density >50 kg/m3 for supplementary insulations

 

 

Polyuretane foam  – PUR

Properties according to standard EN 253, calculated continues operating temperatures 140°C for 30 years. Maximum short operating temperature: 150°C.

Specific weight of grain (EN 253, čl. 4.3.3.1) > 60 kg/m3
Total specific weight (EN 253, čl. 4.3.3.2) > 80 kg/m3
Thermal conductivity < 0,027 W/(mK)
Water absorption    ≤ 10%
Compression radial strength at 10% compression min 0,3 MPa
Sheering axial strength before and after ageing at 23 ± 2°C min. 0,12 MPa
  at 140 ± 2°C min. 0,08 MPa

 

Jacket HDPE  pipe

For underground application HDPE jackets with corona-treated surface are used. This ensures an optimum adhesion between outer casing and insulation.

Density 960 kg/m3 (+20°C)
Thermal tensibility coefficient 180.10/°C
Melt flow rate (MFR 190/5) 0,35 ÷ 0,65g/10 min
Thermal conductivity 0,43 W/mK
Strength tensile ≥ 17 MPa

 

Jacket pipe SPIRO

For aboveground systems jacket pipes made of spiral coiled galvanized steel  (aluminium) belt (according to PA 12 0314, or DIN 24 145) are used.

 

Sliding system designing

All the basic designing principles of bonded system (up to 145°C) are applied for sliding system. The sliding piping system is delivered as one functional unit, please consult with us all construction parameters, mainly expansion issues.

 

Thermal losses

This data can be found in COMPONETS section, where it is stated the loss per 1 m of piping / 1°C, assuming underground application, soil temperature 8°C and soil lambda 1,5 W/m/°K.

Thermal dilatation compensation

For calculation of thermal extension of service pipe , the same principals are used as for bonded system. Please take into consideration possible sudden temperature changes of steam and mechanical stresses in the system.Compensation components as permanently working axial compensators or dilatation elbows are used in the pipeline to absorb expansion. Dilatation elbow are special components, in which carrier pipe is separated from insulation layers and can freely move inside the component.

 
When calculating axial forces, it is necessary to take into consideration the friction force between carrier pipe and sliding layer  - value is set to 10kPa by internal standard PIPECO N03-97. The value of friction stress is applied to perpendicular projection of  service pipe in dilatation section. Another force element in dilatation section between two anchors is created by resistance of axial compensator (if used) and this value is stated by compensator manufacturer as force per 1mm of compensator compression. Calculation of expansion section is based on above mentioned parameters and the stress in service pipe must not exceed allowed value 150 MPa.

 

The installation

The installation is done without pre-heating. No compensation pads are used in elbows. Because the carrier tube is permanently moved axially into the compensator, it is necessary to ensure that the influence of axial forces prevent carrier tube buckling and ultimately jamming compensator. Therefore, in the prescribed distances in front of  axial compensator,  bitumen cardboard is wrapped around casing HDPE pipe to protects the casing from damage during micro-movements.

Plastic PPR pipes

Posted in Production range

 General description

Thermal pre-insulated plastic piping system - polypropylene PPR-3 – is designed for distribution of domestic hot water and drinking water, as well for chemical agressive media (to be consulted with supplier). The protective jacket pipe for underground application is made  of HDPE, for above ground application SPIRO pipes is used. As insulation component is PUR foam used. It is a bonded system – all components are firmly attached to each other and do not move. This has to be taken into consideration when calculating dilatation.
The axial pipes dilatation is limited by friction force acting between jacket pipe and sand trench. The stress is absorbed by PPR- pipe shape change (thickness and diameter) and in firm PUR foam by transferring the stresses to sand trench. For underground application, there is no need to use any dilatation elements. Before using the piping system, pipes must be backfilled and properly compacted.
 
 

 
Materials 
 
Carrier pipe copolymer PPR-3, outside diameter 20 - 110mm, standards: DIN 8077, DIN 8078, DIN 4726, DIN 16962, tlakové rady: PN16, PN 20
Thermal insulation PUR - foam:  EN 253 
Casing pipe HDPE for underground application, diameter 90÷560 mm:  EN 253 , SPIRO for underground application
pipe construction uninsulated ends 160 ± 10 mm for butt or electrofussion welding
 
 

 
Pipe construction

The ends of PPR pipes are not insulated in the length of 200±10 mm.
 

Allowed operation pressures, based on temperature:
 
 Water temperature 
 ( °C ) 
 Allowed operation pressure 
(MPa)
50
1,24
60
1,03
70
0,78

Other pressure classes (PN20, PN25) on demand. PPR system can be regularly overheated up to 70°C to destroy mycobacteria from the system.
The minimum durability of thermal pre-insulated PPR pipes during permanent thermal and pressure load is 30 years.
 

 
Production range

Thermal pre-insulated PPR pipes are supplied with the lengths 6 m (12 m).
Thermal losses – underground application - for media temperature 60 °C
 
 PPR pipe 
 d/t [mm]
 HDPE casing 
D [mm]
 weight 
 [kg/m] 
 Thermal loss 
 [W/m] 
20 /2,8
90
1,3
7
25 /3,5
90
1,4
8
32 /4,5
90(110)
1,5 (1,9)
10 (8)
40 /5,6
110
2,1
10
50 /6,9
110 (125)
2,3 (2,7)
12 (10)
63 /8,7
125 (140)
2,9 (3,6)
14 (12)
75 /10,4
140
4,0
15
90 /12,5
160
5,6
16
110 /15,2
200
7,8
16
 

Other dimensions or enforced insulations can be supplied on demand. Production program for PE servis pipe is 50, 63, 75, 90, 110, 125, 140,160,180, 200, 225, 250, 300 mm.

 

 
Thermal  pre-insulated elbows PPR (90°, 45°, 30 supplied in standard arm lengths (L = 1 + 1 m), or according to the agreement. The dimension of HDPE jacket corresponds to the jacket dimension of straight pipe.
Thermal pre-insulated branches PPR (T - straight, saddle, P - branches) are standard - L = 2 + 1 m – or according to the agreement

Thermal pre-insulated diameter reduction is standard - L = 2 m – or according to the agreement

Transitions PPR pipes to steel (or other) , eventually valves are provided by flanged welded-on, or plastic-metal welded-on thread joints (up to A75 mm).

End sleeves, end caps, wall sealing, flanged valves etc. can be supplied on demand 



Installation of  pre-insulated  PPR pipes

No dilatations has to be taken into account when burying pipes min.. 0,5m under ground.

The minimum ambient temperature during installation must be  +5°C!
You can use standard methods of PPR pipes joining, recommended by suppliers of PPR. Before insulating the joints, do pressure test to ensure, the system is tight.

 

Transportation and warehousing

Pre-insulated PPR  pipes  must be transported and stored on a flat surface, or wooden pads of minimum width of 100mm at the distances 2 m.

Minimum storage temperature is +5°C. Components must be protected from rain and direct sunshine ( to be covered, or stored in the warehouse). When unloading from vehicle – don’t throw on the ground, use fabric strap belts when lifting by crane. Store in pyramids (max. 2m high).  Chemical components, shrinking sleeves, end cups, sealing, valves should be stored in warehouse to be protected against whether conditions.

 

Galvanized pipes

Posted in Production range

General

Pre-insulated system of galvanized steel tubes for the underground or above ground hot tap and drinking water is modular, consisting of straight pipes, fittings and closing valves. Each building component (pipe, fitting), is composed of carrier galvanized steel pipe (DIN 2444), the thermal insulation of CFC-free polyurethane foam and protective HDPE (or Spiro) casing tube. Bonded system design prevents relative movement of the steel tube, insulation and casing tube. Line can be equipped with a monitoring system to monitor possible intrusion of moisture into the insulation. Pre-insulated piping system conform to EN 253

Pipe construction
 
Carrier pipe

Galvanized pipe DN 15 - 100 (diameter 1/2” - 4”):

Size   DN 2440, 2441/STN 425710, 425711
Galvanized pipe              DIN 2444
Material   DIN 17100, St 33.0/STN 11343.0
 
Insulation  PUR - foam: according to EN 253, max. operational temperature 110°C
Casing pipe HDPE for aboveground, diameter 90÷250 mm: according to EN 253 , SPIRO for underground
Ends of the pipe  uninsulated end:150 ± 20 mm
 
 

Production range
 
Lengths
 
L = 6000±50 mm
Insulation thickness:
  
 3 insulation series
Casing pipe
 
HDPE - underground 
SPIRO - aboveground
Leak detection:
 
on request
  
 
 
 

d – outer diameter of galvanized steel pipe

D – outer diameter of jacket (t – wall thickness)

L – steel pipe length
 
 
Basic insulation

 DN


Galvanized pipe
 D x t 
 [mm]
casing HDPEpipe
 D 
 [mm]
weight 
 [ kg/m´]
15
1/2”
21,3 x 2,65
90
2,7
20
3/4”
26,9 x 2,65
90
3,0
25
1”
33,7 x 2,95
90
3,8
32
1 1/4”
42,4 x 2,95
110
4
40
1 1/2”
48,3 x 2,95
110
4,0
50
2”
60,3 x 3,25
125
6,0
65
2 1/2”
76,1 x 3,25
140
8,0
80
3”
88,9 x 3,65
160
10,0
100
4”
114,3 x 4,05
200
15,0
 

Stronger insulations (B and C insulation class) can be delivered as well. Other wall thickness of carrier pipes can be delivered on request. Joints insulation is identical as for standard steel production range. 

 

Compensation of thermal pipe extension, method of deposition


When temperature changes pipeline length is changed according to equation:

Δlx = l . α . Δt   

α – coefficient of linear expansion

ΔT – temperature difference installation and operation

L – length messured


The length change is also influenced by friction force depending on the backfill and diameter of casing pipe (the range is from  1,3 kN/m to 8 kN/m of the pipe). Basically it is possible to use  2 methods of pre-insulated galvanized steel piping installation.

  •   cold, with the use of compensation
  •   with thermal pre-stress (tprest = 30 ... 35°C) before backfilling of piping line
Cold installation
Lm (izolácia triedy A) [m]
 DN 
 H=0,6m 
 H=1,0m 
 H=1,4m 
15
13
9
7
20
20
12
9
25
29
18
12
32
32
19
14
40
35
21
15
50
43
27
19
65
49
30
21
80
55
33
24
100
56
35
25

The method of installation galvanized steel pre-insulated pipes in cold state recognize that allowable stress in the pipe will be exceeded at Media <70 ° C. Then the distance ( at the depth of H ) between the two compensatory elements must not exceed 2xLm ( Lm - shown in the table ) .

For insulation series B is Lm reduced by 12 % . 

In the case of cold state installation method with a long pipeline without the possibility of changing the direction ( compensation element ) is used axial compensators with or without anchors.

Small changes of direction in the trench can be up to 4 ° adjusted by weld . 


Installation
For a secure connection of galvanized steel pipes is recommended method of company UTP Schweissmaterial, with additional material UTP1 (UTP1 MR) and flux-UTP Flux HLS-B. This method ensures undamaged zinc coating on the pipe and high strength joints (see user manual of this company.