David Clayton

Product Manager

FUSION PROVIDA

Severn Trent Services

NDC & EXPORT

FUSAMATIC

Hire & Repair

NDC WAREHOUSE

PIPE SYSTEMS

HEADQUARTERS

EQUIPMENT

EXPORT WAREHOUSE

DUCTILE IRON PIPE YARDCHESTERFIELD DUCTILE GROUP

• Automatic Butt Fusion Machines• Electrofusion Control Boxes• Electrofusion Fittings• Fabricated & Spigot Fittings• Polyethylene Pipe Production• PetroFuse• Aquaculture• Landfill Systems

Manufacturing Capabilities

• Easily formed into complex shapes by extrusion, injection moulding etc.

• Good working temperature range (-20 to +50 C)• Corrosion resistance / Chemical resistance• Good strength to weight ratio• Reduced transportation & handling costs• Easily joined ( E/F & B/F)• Flexibility of buried system• Pipe system is only as good as its joints

Why is Polyethylene used

PIPE INSERTION PIPE BURSTING

NO DIG TECHNIQUES

Electrofusion / Butt Fusion

Molecular Joint - Joint Strength Equivalent to Pipe.

Fully End Loaded System.

Flexibility.

Corrosion resistance.

Degree of quality control & traceability

50 Year Life

Cross Section of a Coupler

Fusion Zone

Terminal Pin

End Cold Zone

Centre Cold ZonePipe Stop

PRODUCTION PROCESS

TERMINAL PIN

FUSION ZONE

STACK

COLD ZONE

Cross Section of a Tapping Tee

THREAD

PRODUCTION PROCESS

Criteria For E/F Jointing

• “Clean” surfaces (interface)

• Steady electrical / heat input

• Generate melt pressure

• Heat soak time

• Minimal tensile load / movement

• Cooling period

Joint Assembled Prior to FusionGap between the pipe andcoupler

.

Joint at the End of Incubation Period

touching

Molten polymer

Coupler & pipe

End of the Joint Consolidation Phase

Frozen polymer in cold zone

Expanded pool of molten polymer

Completed Electrofusion Joint

Shrinkage accommodating inwardmovement of pipe

High strength electrofusionweld

Quality Checks

• Ensure cleanliness of the joint area.

• Check around the joint area for visual signs of scraping.

• Check fusion indicators have risen.

• Check that no molten material or wire has exuded from the fitting.

• Check saddles are square to the main.

• Take printout of joint data.

Fusion Indicators• Cooling & Inspection

Electrofusion joining of PE pipes

Current Profile

Pipe Not Scraped

Incorrect Scraping

Over Insertion

Under Insertion

Misalignment

Pipe Ends Not Cut Square

Wire Movement

Moisture Scraping

Good Jointing Practice

• Check equipment• Scrape pipe• Use clamps• Adhere to fusion / cooling time• Check joint

• OPERATOR AWARENESS

EF Fitting Failure Mechanisms

• Joint Failure >99% of reported EF fitting failures are a direct result of some form

of poor site practice.

• Ductile Creep Rupture–High pressure short failure times (20°C tests).–Attributable to tensile strength of resin.

• Slow Crack Growth–Lower pressures, longer failure times (80°C tests).–Attributable to SCG susceptibility of resin.

(All the above refer to failures during Hydrostatic testing)

DUCTILE RUPTURE

SLOW CRACK GROWTH

Butt Fusion

Butt Fusion Machine

1) CHASSIS

2) TRIMMER

3) HEATER

4) POWER UNIT

5) TIMER

Key Parameters for Butt Fusion

• Temperature

• Pressure

• Time

• Distance

• Sequence

• ISO 11414 : 1996(E)

Standard Cycle for Butt Fusion

Phase 6 tPhase 5Phase 1 Phase 2

Phase 3Phase 4

Manual Input – Butt FusionGreat results when done correctly, however heavily relied on a good operator carrying out the job correctly.

Poor operators could – • Reduce time at each stage• Miscalculate pressures• Over or under heat pipe ends• Miss stages out, such as trimming• Ignore instructions for dummy welds

Look up table for Manual Butt Fusion

New Developments – Automatic Butt Fusion

Data Storage

• All joint statistics displayed on the printout

• Summary of joint status given

If the material properties are correct it is impossible for a bad joint to go un-noticed

• Individual record for each joint

• Can be printed or downloaded

• All beads shall be removed and assessed

Joint Analysis

Review Joint Records