Productivity of heating element butt welding - pt-plast.ru · July 2014 – technical modifications...

July 2014 – technical modifications reserved

Productivity of heating element butt welding


Coauthor: Graduate engineer (UAS) Holger Hesse Plastic pipe manufacturer egeplast Werner Strumann GmbH & Co

3R special edition 1/2013

3R 04-05/2013

English version


1. Previous studies

2. Many influencing factors

3. Approach / guide values

4. Hints

Structure


Research report

Source: Internet download dated 02/20/2014 http://www.dbu.de/OPAC/ab/DBU-Abschlussbericht-AZ-27249.pdf

Ecological-economic evaluation and process optimizing of joining procedures using the example of plastic pipe systems Project executing organization: SKZ - Das Kunststoff-Zentrum Supported by: German Environment Foundation (DBU)


Research report

Source: Research report SKZ

Cooling

Joining pressure build-up

Change-over

Heating

Bead-up

Handling

Welding device tramming

Cooling


Change-over

Heating

Bead-up

Handling


Cooling


Change-over

Heating

Bead-up

Handling


Cooling


Change-over

Heating

Bead-up

Handling

Heating


Research report

d 63mm d 110mm d 160mm d 250mm

1 welding machine 23 17 13 10

2 welding machines 45 34 25 19

Maximum number of heating element butt weldings of PE pipes per day in the laboratory

Lab weldings



Survey of people with questionnaire

d 63mm d 110mm d 160mm d 250mm

Variance 20 – 25 12 – 25 8 – 20 5 – 15

Average number of possible weldings

22,5 17,3 12,2 10

Huge variance

similar:


Maximum number of weldings according to survey


Source: ISCO Fusion Manual, 2007, ISCO Industries LLC, USA, http://www.isco-pipe.com/media/7814/fusion%20manual%202007%20metric.pdf Internet download 02/21/2014

Maximum number of heating element butt weldings of PE pipes per day (8 h – 10 h) according to the information of a US manufacturer.

d 20mm –

d 90mm

d 110mm –

d 200mm

d 250mm –

d 450mm

Variance 30 – 60 24 – 48 12 – 24

much more than in Germany

ASTM parameters

An example from the USA


1. Previous studies



4. Hints

Structure


Many influencing factors


Many influencing factors

Machine concepts

Cooling times

or „issues"?

Significant influences?


Welding parameters

Country/spreading Special

parameters Comment

DVS 2207 part 1

(September 2005)

Germany / is also widely

used in many European

countries, in South

America, in Asia

0,15 N/mm²

joining pressure

Heating element

temperature

220°C for

PE100

Extensive

research on long

term stability has

been carried out

60 – 90 PSI

(0,41 – 0,62

N/mm²) joining

pressure

Heating element

temperature

400 - 450°F

(204 - 232°C)

USA / is particularly used

in the USA but also in

South America and other

countries

12


Welding parameters

Harmonization resp. worldwide valid welding standard Possible? Preferable? Reasonable?

From our point of view: YES!

WIS (United Kingdom), NEN (Netherlands), UNI (Italia, Electrabel (Belgium), DS/INF (Denmark), etc.

International / as ISO

norm of course applied

internationally, however

it is not as widely used

as above DVS guideline

or ASTM norm

Three methods

are selectable.

0,17 N/mm²

0,52 N/mm²

joining pressure

Heating element

temperature

220°C –

245°C

Comment Special

parameters Country/spreading Short term


Welding parameters

Source: DVS publishers, DVS guideline 2207-1 (September 2005)


"The reduction of the cooling time up to 50 %, that means joining pressure release and removal of the welded part from the welding equipment, is allowed under the following requirements:

– the welding is done under workshop conditions

– the removal from the welding equipment and the temporary storage are causing only slight loads to the joint

– it concerns components with a wall thickness of ≥ 15 mm."

DVS 2207-1: Cooling times

Source: DVS publishers, DVS guideline 2207-1 (September 2005)


Source: ASTM F2620 – 12, Standard Practice for Heat Fusion Joining of Polyethylene Pipe and Fittings, ASTM International, www.astm.org, West Conshohocken (USA), 2012

"8.3.7 Hold the molten joint immobile under fusion pressure until sufficiently cooled. Cooling under pressure before removal from the butt fusion machine is important in achieving joint integrity.

Maintain fusion pressure against the piping component ends for a minimum of 11 minutes per inch (25.4 mm) of pipe wall. For ambient temperatures 100°F and higher,

additional cooling time may be needed. Avoid high stress such as pulling, installation or rough handling for an additional 30 min or more after removal from the fusion machine (only 10 minutes additional cooling time is

required for IPS 1 in. and smaller pipe sizes). Do not apply internal pressure until the joint and surrounding material have reached ambient air temperature."

Welding parameters


Welding parameters

pipe wall thickness in mm

cooling t

ime in m

in

+30 min


F F

bead

Welding parameters

residual melt zone


Welding parameters

F

residual melt zone

bead

F


Long term resistance in years

residual melt zone in mm

Welding parameters


mobile or stationary


Mobile application from welding to welding!






Stationary application


Stationary application


Utilities for the handling are not necessary in simple site situations

Machine concepts

Manual operation


Machine concepts


detachable 4th ring

Machine concepts


The machine is moved with external lifting device (e.g. excavator shovel).

Machine concepts

WIDOS 6113

Especially heavy version


Machine concepts

Special machine for narrow conditions Only two clamping rings and small hydraulic cylinders

WIDOS HRG


Manually controlled for more than 50 years

CNC controlled since the 1980s „semi-automatically“

Automatic heating element

Automation


Mobile application

315 - 630

710 - 1.200 1.200 - 1.600

500 - 1.000

Integrated planer and heating element


Machine concepts

WIDOS 12000 with hydraulic crane


Machine concepts


Machine concepts


All-terrain on tracks

Machine concepts

Current generator

WIDOS 12000 mobile on tracks


Project-related mobile welding container

Machine concepts


Number of operators

1 operator

- Manual welding machines for pipes up to appr. d 160 mm.

- Semi-automatic (CNC) welding machines for pipes up to appr. d 250 mm.

- All welding machines with integrated/built-in planer and heating element as well as fully hydraulic operation via remote controll.

2 operators

-Welding machines for pipes from d 315 mm up to appr. d 500 mm. - Welding machines with intergrated crane (hydraulic crane or lifting device) for pipes of appr. ≥ d 630 mm.


Planning

Example for a planning (freehand) sketch:


1. Previous studies



4. Hints

Structure


Sub-processes analogue to the SKZ research report

Approach

Welding machine on location of the welding,

heating element still in cool condition.

Heating

Handling (clamping, planing, cleaning)

Bead-up

Heating

Change-over


Cooling

Unclamp pipe, carry machine to the next

welding

End of first welding

Time in min

Example da 110 mm, SDR 11,

also see SKZ research report

Subtotal 46,32 min

Start


Approach

End of last welding

Sub-total 72,64 min End of second welding

Sub-total 46,32 min End of first welding

Handling (clamping, planing, cleaning)

Productivity of

butt welding 8h (working day)

Number of weldings

≤ 480 min (= 8h)


Guide values

d [mm]

SDR 1 welding machine

2 welding machines

3 welding machines

Operator

50 11 30 49 * 1

110 11 17 34 * 1

200 11 11 24 31 1

315 11 7 18 23 2

500 11 5 12 16 2

630 17 5 11 13 2

1.000 17 4 10 12 2

1.200 21 4 10 11 2

1.600 26 3 7 ** 2

2.000 26 3 7 ** 2

Number of weldings / 8 h (working day) in good conditions


1. Previous studies



4. Hints

Structure


Hints for increase in productivity

Hint no. 1: The use of 2 welding machines considerably increases productivity.

Hint no. 2: Welding machines on wheels or tracks are beneficial for the transport out in the fields.

Hint no. 3: Make use of a welding machine concept appropriate for the situation on the construction site.



Hint no. 4: Since the base frame of the welding machine is „on hold“ during cooling (pressing the pipes together), it is possible to operate another base frame with the heating element / planer. And: power consumption is reduced by almost 50%.

and now?:


Hint no. 5: The use of high quality welding machines avoids breakdowns on the construction site.


90x8,2 SDR 11Code 10 10 = 90x8,2 SDR 11Code 10 1o =

Hint no. 6: High quality pipes facilitate mismatch compensation and help saving time. Advantages of pipes with integrated protection layers.


Hint no. 7: The use of professional tools and accessories also shorten the time for preparations.



Online tool www.webkalkulator24.de


Thank you very much for your kind attention!

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Productivity of heating element butt welding - pt-plast.ru · July 2014 – technical modifications...

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