MWANZA SEMINAR

22nd July 2015

PLASCO OVERVIEWPE PIPE JOINTING SYSTEMS

JOINTING TECHNIQUES FOR PE PIPES

There are a number of techniques for jointing of PE pipes

Compression fittings

Stub & flange - mechanical

Butt fusion

Socket fusion requires special fittings

Electro fusion requires special fittings

Compression fittings

Mainly for small diameters

Socket fusion

For small diameters Special fittings and tools required

Mechanical jointing - PE Stub & Flange

For large diameters Especially useful when connecting to other piping systems

Mechanical jointing - PE Stub & Flange

For large diameters Especially useful when

connecting to other piping systems

Mechanical Jointing

Demanding conditions or remote locations

End restraint type fittings

Connecting to other materials and flanges

Butt fusion

Butt fusion technology is the safe,

reliable and favorable method of

jointing for a wide dimension range.

The fusion areas of the pipes and

fittings are heated to fusion

temperature and joined by means of

mechanical pressure, without using

additional materials. A homogeneous

joint results.

Mechanical, hydraulic and CNC-

guided fusion machines for on site

constructions and the workshop are

available.

Butt Fusion Jointing

Preferred option, joint is as strong as the pipe

No fittings required

Continuous fully homogeneous pipe

Butt fusion

For large diameters Straight joints

Custom-made angles for fittings possible

Butt fusion

For large diameters Forming continuous pipelines with flexible and leak free joints

No fluid losses during transportation

Butt fusion video

Electro fusion

In the electro fusion process a heating wire

permanently mouled into the fitting gets

heated by current at a low voltage. The

surrounding material around the wire gets

melted and expands due to the warming. The

melt starts closing the gap between pipe and

fitting, leading to a heat transition to the pipe

which also gets heated and melts in the

welding zone.

The pipe material also expands.

The increasing material expansion between

pipe and fitting, which is hindered by the cold

zones outside the welding zone, leads to a

build up a welding pressure between pipe and

fitting and a homogeneous welding

connection emerges.

Electro fusion

For all diameters Only for jointing PE to PE

To be used when pipes cannot be butt welded

Special fittings and equipment required

Electro fusion video

Electro fusion Branch Saddle

Branching-off without cutting

the pipeline is possible using

Electro fusion Branch Saddles

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Electro fusion Branch Saddle

System features

Main pipe: d315-2000mm

integratedwindows scraper

Outlet:d160-500mm

Tappingdevice

Cross dimensional, modular installationsystem

freepositioning in axial and radial position

EF Branch Saddle Video

INSTALLATION CONSIDERATIONS

INSTALLATION CONSIDERATIONS

Deliveries and storage on site

Pipe handling

Handling of pipes and fittings on site

Site damage

Thermal effects pipe expansion and contraction

Welding management on site

Deliveries and storage on site straight pipes

Ensure that pipes and fittings are delivered to site with the correct

documentation and that pipes are

marked in accordance with ISO 4427

Generally pipes can be stacked in a regular manner up to a height of 3 m

Pipes should be placed on soft ground or sand. When stored on concrete,

rocky or uneven ground timber battens

should be used

Provided the pipes are produced using a good quality pre-compounded

material the pipes do not need to be

covered or shaded

Deliveries and storage on site coiled pipes

Coils are to be delivered with the correct documentation and

marking

Coiled pipe should be stored flat and on firm level ground which

has protection for the bottom coil.

Where space is limited coils can be stacked up to a height of 2m

Wooden battens placed below the bottom coil and between coils

Where large diameter coils are to be stored vertically, coils must be

secured in racking

Handling of pipes and fittings on site

Pipes should never be thrown or dropped of vehicles or platforms

Always use wide nylon or polypropylene slings rather than

metal slings, hooks or chains

when handling pipes

Place pipes or fittings in contact with lubricating or hydraulic oils,

gasoline, solvents or other

aggressive materials

Do not remove protective covers, bags or end caps until required

Management of site damage

It is not unusual for the pipe surface to be lightly scratched, scuffed or scraped

during installation and this is acceptable

Individual scratches of up to 10% of the pipe wall thickness will not effect the

performance of the pipe (guidelines issued

by the US Plastic Pipes Institute and

several pipe producers)

If there are individual scratches of greater than 10% of the wall thickness or large

areas of very heavy scratching, these

should be cut out and that section of the

pipe discarded

Thermal expansion of PE100 in comparison

to other pipe materials

0 0.5 1 1.5 2

Steel

PVC

HDPE

m

Expansion

Change in the length of a 1 km pipeline with a 10 oC rise

0.1m

0.8m

1.8m

Thermal effects pipe expansion and contraction

The coefficient of thermal expansion for PE100 is 0.18 mm/m/OC

Thermal movement on unrestrained pipes in hot weather will be obvious snaking of the pipeline

Experienced pipe fitters can easily cope with this.

One method is to cut and fix the lengths of pipe at either end when the pipe is relatively cool. If connections are made with a straight pipe

under hot conditions there will be a stress on the joint when the pipe

cools and shrinks

Once buried there is very little thermal movement due to constriction by the backfill, pipe skin friction and a much smaller variation in

temperatures, but still use restrained joints

Welding management - the butt weld process

220C

After positioning of the pipes

end in the welding machine

and planing of the pipe ends

Heating of the pipe ends

until then are semi-molten

Double roll back welded

joint after removal of the

heating element and

cooling under pressure

Pipe

Pipe

Heating element

Welding management on site

- training, certification and good practice

Only welders that trained, tested and certified in accordance with

an international standard (e.g.

Certified HDPE Pipe Welder - GW

330) should operate machines 5 day course

Site staff should be trained and certified as supervisors - 2 or 3

day course

Care and clean site conditions are essential for good welding

Record sheets and/or a welding machine to record every joint

Welding management on site

- training, certification and good practice

Welding management on site

- training, certification and good practicePlasco Limited Field Job Card

Form 07.03.01

Rev: 0

Job Card No

Customer Details

Customer Name IOR/Contract No

Contact Name Tel No

After Hours / Cell No Fax No

Physical Address Date

Safety Considerations

Lockouts Height work Safety Personal Protective Equipment (PPE)

Mechanical Ladders Cranes S/Shoes Earplugs Masks

Electrical Slings Fire Gloves S/Glasses

Reflective Jacket Hard Hat

Customer Requirements

Names of Welding Team

Team Leader Welder 1 Welder 2

Equipment Requirements

Equipment, Machine and Tools Machine No Qty Remarks

Work Times

Date Location Weld

Numbers

Welds

Completed Start Time Finish Time Total Hours

Customers Signature

Additional Comments

Team Leaders Signature Technical Services Manager

Welding management on site examination and testing of welds in the jointing section

Random welds are to the cut out immediately after being

welded and tested in a

laboratory. Some specifications

call for 1% of all welds to be

tested

Initially every joint should be inspected. Once welding

process is up to speed

inspections need only be made

on a regular basis

Visual inspection & bend back testing of the weld beads on a

regular basis gives a good

initial indication of weld quality

Send the welders and supervisor off site!

On site hydrostatic testing of the pipeline

PE is visco-elastic and creeps under stress. The pressure gauge falls back as the pipe expands under pressure.

Therefore with a single phase test it is not possible to tell whether falling pressures are due to leakage or creep of the material

The three phase test eliminates the material response. Therefore any loss of pressure should therefore be from leakage.

Steel pipes are tested primarily for integrity ie. no explosions whilst PE pipes are primarily tested for leak tightness of welded joints.

PE tests must be done in one working day. If any stoppage then depressurise the pipeline and start again.

In hot climates its best to test when temperatures are either stable or falling in order to minimise problems due to thermal pipeline

expansion.

Pipelines are like a chain. They are only as

strong as their weakest link

PE100 pipeline projects must be designed by engineers who are familiar with the

material and whom have been trained in

its proper system design

When comparing pipeline material options designers should consider the entire

construction cost, not just the cost of the

pipes alone. If possible take in to account

the whole life cost of the pipeline utilities need to collect the data!

The pipes must be manufactured from a high quality material (PE100+) in a high

quality facility and in accordance with

national and international standards

Pipelines are like a chain. They are only as

strong as their weakest link

They must be joined by trained and certified welding technicians

using equipped that is tested

and certified in accordance with

international standards

The pipelines must be correctly installed in accordance with the

standards and engineering

specification by an experienced

contractor employing trained

staff

The supervision of the works should be undertaken by a

suitably trained and experienced

site team

Conclusion

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PE100 pipeline projects must be designed by engineers who are familiar with the material and whom have been trained in its proper system design

When comparing pipeline material options, designers should consider the entire construction cost, not just the cost of the pipes alone. If possible take into account the whole life cost of the pipeline utilities need to collect the data!

The pipes must be manufactured from a high quality material (PE100+) in a high quality facility and in accordance with national and international standards

They must be joined by trained and certified welding technicians using equipment that is tested and certified in accordance with international standards

The pipelines must be correctly installed in accordance with the standards and engineering specification by an experienced contractor employing trained staff

The supervision of the works should be undertaken by a suitably trained and experienced site team

THANK YOU

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PLASCO LTD.

Your one-stop-shop for

piping solutions

www.plasco.co.tz

plascosales@plasco.co.tz

Sales Hotlines : +255 717 752 726 / +255 686 350 543 / +255 769 756 495