Fusion Procedure of HDPE Pipe

Provision of EPCC Service for Sewage Water
PROJECT NAME Intake Project
PROJECT NO. 027-SC-19

DOCUMENT NAME Fusion Procedure of HDPE Pipe
DOC NO. EBS2-DWIS52-EBPL-PRFW-1009-G01 Page no. Page 1 of 21
PROVISION OF EPCC SERVICE FOR SEWAHE WATER INTAKE PROJECT

CONTRACT NO; 027/SC/19
Fusion Procedure of HDPE Pipe
01 21 June. 2021 RE-ISSUED FOR APPROVAL REDHAA THAMIR ZULFOKAR
00 02 Feb. 2021 ISSUED FOR APPROVAL REDHAA THAMIR ZULFOKAR
REV. DATE DESCRIPTION PREP. CHECK. APP.


TABLE OF CONTENTS
1.0 OBJECTIVE…………………………………………………………………….
2.0 CODES AND REFERENCES ……………………………………………….
3.0 TERMS AND DEFINITIONS …………………………………………………
4.0 STORAGE, HANDLING AND TRANSPORT ……………………………..
5.0 KEY FACTORS FOR QUALITY FUSIONS…….………………………….
6.0 MEASURES BEFORE START FUSING …………………………………..
7.0 FUSION PREPARATION …………………………………………………….
8.0 BUTT FUSION …………………………………………………………….…..
8.0 QUALITY CONTROL …………………………………………………………
8.0 HSE PRECAUTION MEASURES …………………………………………..


1.0 OBJECTIVE
This document describes the preparation and Fusion procedures of the HDPE
pipe butt weld; it is to insure that the fused joint will perform equal to or greater
than pipe.
This document outlines the procedures for joining HDPE pipe & fittings by butt
fusion.
Materials that have been pre-qualified to be joined by this fusion procedure is PE
4710
2.0 CODES AND REFERENCES
SPS 125 Polyethylene and Polypropylene Pipe and Pipe Fittings

ISO12176-1 Plastic Pipes and Fittings- Equipment for fusion Jointing of
Polyethylene system
ISO 10838-2 Mechanical Fittings for Polyethylene Piping System
ISO 10838-3 Mechanical Fittings for Polyethylene Piping System
ISO/TS 10839 Polyethylene Pipes and Fittings Code of Practice for Design,
Handling and Installation
BS ISO 21307 Plastics pipes and fittings —Butt fusion jointing procedures for
polyethylene (PE) pipes and fittings used in the construction of
gas and water distribution systems
3.0 TERMS AND DEFINITIONS
For the purposes of this document, the following terms and definitions apply.
3.1 cooling-cycle reduced pressure
reduced pressure, used in the cooling cycle of the dual low-pressure procedure
after jointing time
3.2 cooling time in the machine under pressure
time period during which the butt fusion joint remains under pressure when still
clamped in the machine
3.3 cooling time in machine without pressure or out of machine
additional cooling period that may be required after the cooling time under
pressure to ensure optimum joint strength, particularly when working at high
ambient temperatures and prior to rough handling or pipe installation
3.4 drag pressure
gauge pressure required to overcome, on a given machine, the sliding frictional
drag force of the machine and pipe
3.5 fusion jointing pressure
actual pressure exerted on the pipe or fitting ends during jointing
3.6 gauge pressure
actual pressure read by the gauge of the butt fusion jointing machine

3.7 heater plate removal time heater plate dwell time

time taken to separate the pipe or fitting ends from the heater plate, remove the
heater plate and close the carriage in order to bring the molten pipe or fitting
ends together
3.8 heater plate temperature
measured temperature on the surface of the heater plate where the pipe or
fitting wall cross-section makes contact
3.9 heat soak pressure
pressure required to maintain the pipe or fitting in contact with the heater plate
3.10 heat soak time
time during which the heater plate is in contact with the pipe or fitting ends at the
heat soak pressure
3.11 minimum bead size after heating
minimum value of bead size to be attained after completing the heat soak time
3.12 initial bead-up pressure
pressure exerted on the heater plate by the pipe or fitting ends during the bead-
up phase of the jointing cycle, including drag pressure exerted on the pipe or
fitting ends during jointing
3.13 initial bead-up time
time taken to generate a continuous bead, of a specified dimension, around the
circumference of the ends of the pipes or fittings
3.14 initial bead-up size
bead size formed on the pipe or fitting ends during the bead-up phase
4 STORAGE, HANDLING AND TRANSPORT
4.1 General
Polyethylene pipes are available in coils, drums or straight lengths. Fittings are
normally individually packed.
Mishandling of the pipes and fittings shall be avoided. Since polyethylene pipes
are relatively soft, poor handling techniques may be result in gouges, scratches,
cuts or holes.
4.2Storage
Straight pipes shall be stacked on a reasonably flat surface free from stones or
other projections or sharp objects likely to deform or damage the pipes. Pipes and
fittings shall be stored in such a way as to minimize the possibility of the material
being damaged by crushing, piercing or extended exposure to direct sunlight.
Pipes may be stored outside in direct day light provided the storage time is
monitored and minimized to avoid exposure to excessive levels of UV radiation
likely to impair the properties of the product relative to its “as purchased”
condition.

The distances x between support frames holding packs of pipes together shall be
equal in order to allow the frames to be stacked (see Figure1).
Straight pipes shall rest evenly over their whole length.

The support frame shall not be nailed together and shall be constructed in such a
way that the load is directly supported by the frame and not by the pipes.
Figure 1—Support frame
4.3 Handling
Do not drag or throw the pipes along the ground. If handling equipment is not
used, choose techniques which are not likely to damage the pipes and/or fittings.
The flexibility of polyethylene pipes is reduced in cold weather, and more care
needs to be taken when handling them in winter. If the temperature falls below–
15°C for straight pipes and for fittings, or below0°C for coiled pipes, special
handling instructions shall be followed.
Initial handling and storage of straight pipes shall be made with the pipes in
packaged form, thus minimizing damage during this phase. When loading,
unloading or handling, it is preferring able to use mechanical equipment to move
or stack the packs.
4.4 Transport
When transporting straight pipes, flat bed vehicles with a partition shall be used.
The bed shall be free from nails and other protuberances. The pipes shall rest
uniformly on the vehicle over their whole length. The vehicle shall have side posts
which are flat with no sharp edges. During transport, the pipes shall be securely
held in such a way that movement between the pipes and the posts is minimized.

5.0 KEY FACTORS FOR QUALITY FUSIONS
Quality fusion requires all of the required tools and equipment, and following all of
the steps in the procedure in the correct sequence. The fusion procedure prepares
and aligns the surfaces, heats the mating surfaces to the proper melt consistency,
joins the surfaces together under pressure, then cools the joint under pressure.
Faulty fusion is caused by improper or defective equipment, omitting steps or doing
things out of sequence. Faulty fusion may be hazardous.
The key factors below necessary for quality fusion are:
- Fusion tools and equipment must be correct for the job, and in proper working
order;
Each fusion procedure requires specific tools and equipment to do the job properly.
Using poorly maintained, damaged, or incorrect tools and equipment can cause a
poor fusion, and may be hazardous. Use only the correct tools and equipment for
the job. Do not use defective or improper tools or equipment. Follow the equipment
manufacturer’s procedure for equipment maintenance.
- The fusion operator must be proficient in tool and equipment use and operation,
and proficient in fusion procedure;
The operator should be thoroughly familiar with the tools and equipment and their
use and operation. Improper use or an incorrect operating sequence can cause a
poor fusion, and may be hazardous. Know how to use the equipment, and follow
the manufacturer’s instructions
- Pipe and fitting surfaces must be clean and properly prepared;
Dirty or contaminated, or poorly prepared surfaces that do no mate together

properly cannot produce a quality fusion.
Clean and prepare the surfaces before joining. If contamination is reintroduced,
clean the surfaces again.
- Heating tool surfaces must be clean, undamaged and at the correct surface
temperature;
Heating tool faces have non-stick coatings for quick, complete release from melted
HDPE. Dirty or contaminated heating tool faces can cause poor fusion, and
damaged coatings may not release properly from the melt. Use only wooden
implements, and clean, dry non-synthetic (cotton) cloths or paper towels to clean
heating tool faces. Never use spray chemicals or metal tools on heating tool faces.

The specified temperature is the temperature on the surfaces that contact the pipe
or fitting being joined, not the heating tool thermometer temperature. Use a
pyrometer or infrared thermometer to check for uniform temperature across both of
the component contact surfaces. (Temperature indication crayons are not
preferred.
6.0 MEASURES BEFORE START FUSING
- The Fusing zone must be protected against bad weather influences such as wind
and moisture. If it is ensured by suitable measures (preheating, wind shelter) so
the conditions are suitable for working
- For the production of perfect fusion joints, it is very important that the joining
area, heating tools should be clean and free of oil and grease
- Clean the inside and outside of the pipe or fittings to be joint with a clean dry
cloth
- Remove all foreign matters from pipe surface where they will clamp in the butt
fusion machine
- Inspect pipe lengths and fittings for unacceptable cuts, gouges, deep scratches
or other deleterious defects. Damaged products should not be used
- Toe-in or necking down is normal at pipe ends, but may need to be removed
when only one of the ends to be joined displays ‘toe-in’. Ensure toe-in does not
result in excess wall misalignment
- Remove surface damage at pipe ends that could compromise the joining
surfaces or interfere with fusion tools or equipment
- Be sure all required tools and equipment are on site, in proper working order and
fueled up
- The pipe and fitting surfaces where tools and equipment are fitted must be clean
and dry. Use CLEAN, dry, non-synthetic (cotton) cloths or paper towels to
remove dirt, snow water and other contamination
- Shield heated fusion equipment and surfaces from inclement weather and winds.
A temporary shelter over fusion equipment and the fusion operation may be
required
- Relieve tension in the line before making connections
- Pipes must be correctly aligned before making connections


7.0 FUSION PREPARATION
7.1 General Fusion Operation
The procedures stated below should be regarded as a general guideline only.

The manufacturer of the HDPE pipe should be asked to supply specific
recommendations for Fusing of their products or materials. Likewise, the Fusing
machine supplier shall supply detailed Fusing procedure for their machines.
Heat fusion bonding is a combination of temperature and force resulting in two

mating surfaces flowing together to produce a joint. Fusion bonding occurs when
the joint cools below the melt temperature of the material. There is a temperature
range within which any particular material may be satisfactorily joined. The
specified temperature used requires consideration of the properties of the
specific material, the fusion equipment being used and the Fusing environment.
The Butt-Fusing is done in several phases and by using several parameters.

The operations can be summarized as follows:
- The alignment of the pipe
- The shaving of the surfaces of the pipe ends
- Cold matching of the HDPE pipes
- Cleaning of surfaces
- Heating of surfaces
- Fusion of surfaces
- Cooling of weld joint
The parameters used during Fusing are:

- Bead-up pressure in bars or psi
- Bead-up height in mm or inches
- Heat soaking time in seconds
- Heat soaking pressure in bars or psi
- Transfer time in seconds
- Fusion pressure in bars or psi
- Cooling time in minutes
These parameters are for information only and shall be compared with the
parameters given by the HDPE pipe manufacturer and the Fusion machine
supplier.

7.2 Fusing Preparation
The Fusing zone must be protected from unsuitable weather conditions (e.g.
humidity effects, wind and temperatures below 0°C). The surfaces to be joined
must be undamaged and free from impurities or loose particles.
7.3 Alignment of HDPE Pipes
The pipes must be aligned when they are clamped into the mirror welder in such
a way that the surfaces are in the same plane (parallel) to each other. The HDPE
pipes can be positioned directly into the Fusing machine. Install the correct
adapter insert for the size of pipe diameter to be used and tighten them to the
machine.
Position the pipe in a way that approx. 40mm is protruding behind the last clamp.
By doing this, you will have approx. 10 to 15mm to shave from, and the
remaining 25 to 30 mm should be sufficient for Fusing.
Once the pipe has been placed in position, the top clamps can be closed. It is
important to tighten the top clamp nuts evenly in order to get a totally circular
pipe, an even clamping pressure must be achieved. Then, make the first dry
matching (press the two pipes to each other) and check the amount of shaving
that will be required.
Table1—Maximum additional angular misalignment


8.0 BUTT FUSION
8.1 Principle
The butt fusion technique consists of heating the planed ends of the mating
surfaces by holding them against a flat heating plate until molten, removing he
heating plate, pushing the two softened ends against one another, holding under
pressure for a prescribed time and allowing the joint to cool (see Figure2).
Figure 2— Butt fusion
Butt fusion is not recommended for pipes 63mm in diameter. Pipes and/or fittings
with fusion ends of different SDR values shall not be joined by butt fusion.

8.2 Butt fusion cycle
The butt fusion cycle can be represented by a pressure / time diagram for a
defined fusion temperature. Different butt fusion cycles are available, depending
on the PE material used, the pipe diameter and the working conditions. The butt
fusion cycle to be used shall be specified in the written procedure. (Figure3.)
Figure3—Example of a butt fusion diagram


Table2 — Parameters of butt fusion diagram shown in Figure3
The pressures shall be chosen so that the required force is produced at the
interface, irrespective off
rictionalandpressurelossesinthebuttfusionmachineanddragresistancefromthepipe
system.
In the case of machines with hydraulic power rams, the force is normally
indicated in terms of the applied cylinder pressure. For such machines, a specific
calibration table is provided that gives the relationship between the real interface
pressure and the pressure indicated by the manometer (pressure gauge).
8.3 Butt fusion temperature
The butt fusion temperature is normally situated between 200°C and 235°C and
is given in the jointing procedure
8.4 Butt fusion jointing
The following gives an overview of the minimum operations necessary to produce

a butt fusion joint with a specified butt fusion cycle and temperature:
- Reduce the drag resistance as much as possible, for example by using pipe
rollers.
- Clamp the spigot ends of the pipe(s) and/or fitting(s) in the butt fusion machine.
- Clean the spigot ends.
- Check that the butt fusion machine is compatible with the pipe diameter and the
prescribed butt fusion cycle.

-Plane the pipes parallel by moving the movable clamp against the planning tool
(see Figure4).
The closing pressure shall be sufficient to produce a steady flow of PE slivers on
both sides of the planning tool. Planing is complete when the pipe face(s) and/or
fitting face(s) are plane and parallel to each other.
Figure4—Planing the spigot ends
- Lower the pressure, keeping the planning tool rotating in order to avoid a burr
on the pipe and/or fitting faces. Move the movable clamp backwards and remove
the planning tool.
- Close the butt fusion machine and check that the pipes are aligned. The spigot
ends of pipe(s) and/or fitting(s) shall be aligned as much as possible and not
exceed the maximum misalignment given in the Table 1.
- The gap between the pipe and/or fitting faces after planning shall be as small as
possible and shall not exceed the maximum gap given in the Table 3.

Table 3 - Maximum gap
- If necessary, clean the fusion surfaces and the heating plate. Polyethylene
residues shall only be removed from the heating plate with a wooden spatula.
- Check that the surface coating of the heating plate is intact and without
scratches.
- Check that the heating plate is at the correct fusion temperature.
-Place the heating plate between the pipe faces. Close the butt fusion machine
against the heating plate to apply the fusion pressure, including the measured
additional pressure, until the specified bead width has been reached(seeFigure5).
Figure 5—Heating the spigot ends


- Reduce the pressure to a level at which contact is just maintained between the
pipe ends and the heating plate
- When the heat soak time has elapsed, open the butt fusion machine and
remove the heating plate. Check the heated pipe ends quickly for possible
damage to the melted ends caused by the removal of the heating plate, and close
the butt fusion machine again. The period between opening and closing shall be
within the maximum time given in the Table 4.
Table4—Maximum time for removing the heating plate
- Store the heating plate in a protective enclosure when not in use.

- The butt fusion machine shall remain closed and under pressure during the
whole butt fusion time and subsequent cooling period. It is important that the
cooling period is respected.
- When the butt fusion and cooling times have elapsed, release the pressure in
the butt fusion machine.
- When removed, the pipe shall be handled with care.
- See Table 5

Table 5 — butt fusion jointing procedure
9.0 QUALITY CONTROL
9.1 General
The pipes, fittings and associated equipment shall be inspected to confirm the
conformity with the laying procedure.
The inspection may be carried out by the personnel engaged in jointing.
Additional inspections shall be carried out by a competent person at a frequency
depending on the conditions of use. The results of each inspection shall be
recorded.
Destructive testing on joints made in the field may also be carried out to ensure
that the quality conforms to the jointing procedure.

9.2 Visual Inspection
- Bead symmetry
Joints shall have a smooth symmetrical bead around the entire pipe circumference
as shown in Figure 6. The depth (A) of the bead depression shall not extend
below the pipe surface.
Figure 6 – Bead Symmetry
- Alignment
Pipes, fittings and valves shall be as closely aligned as possible. The

misalignment (V) shall not exceed 0,1 ln (ln=is the nominal wall thickness).
Where this leads to values of less than 1mm, testing of joints shall be undertaken
to identify the maximum allowable misalignment (see Figure 7).
Figure 7 – Alignment

- Bead width
The bead size shall be as the minimum criteria as shown in Figure 8 and Table 6.
Figure 8, Table 6 - Bead Melt Size
- Bead Removal
Removal of the external fusion bead, using appropriate tools, is possible
without damage to the pipe (see Figure 9). The removed bead is then
available for inspection.
The bead shall be solid and rounded, with abroad root, as shown in (Figure
10). Hollow beads with a thin root and curled appearance may have been
formed with excessive pressure or no heat soak.

Figure 9 – Bead Removal
Figure 10 – Bead Root


Observed Condition Possible Cause
Excessive double bead width Overheating; Excessive joining force
Excessive joining force; Insufficient heating;

Double bead v-groove too deep Pressure during
heating
Flat top on bead Excessive joining force; Overheating
Non-uniform bead size around Misalignment; Defective heating tool; Worn

pipe equipment;
Incomplete facing
Misalignment Component slipped in clamp;

One bead larger than the other worn equipment
Defective heating tool; Incomplete facing
dissimilar material
– see note above.
Beads too small Insufficient heating; Insufficient joining force
Shallow v-groove – Insufficient heating &

Beads not rolled over to surface insufficient joining
force Deep v-groove – Insufficient heating &
excessive
joining force
Beads too large Excessive heating time
Squareish outer bead edge Pressure during heating
Rough, sandpaper-like, bubbly,

or Hydrocarbon contamination
pockmarked melt bead surface
Table 7: Butt Fusion Bead Troubleshooting Guide


10.0 HSE PRECAUTION MEASURES
Safety and prevention first, people-oriented" is the guidance and focus of our
security policy. We will strictly implement and obey the owner's safety production
supervision requirements. During the construction period, the operator's life
safety and health risks are ensured by monitoring and controlling various
potential risks.
10.1 Strictly implement the owner's work permit and personnel entry and exit
permit system. Construction work is prohibited without operation permit in order
to prevent any possible accidents.
10.2 Organize and perform emergency evacuation drilling training to improve

emergency response and escape skills for all personnel.
10.3 In order to ensure safety and minimize the loss of personnel, equipment
and property, an emergency plan for construction work during the rainy season
should be prepared
.
10.4 Strengthen coordination and communication with the owner's safety
management.
10.5 Set up safety warning tapes and operation warning signs on site to prevent
any accidents due to unauthorized personnel entering the jobsite.
10.6 Employees shall be informed that attendance is required at the scheduled

Toolbox Safety Meetings conducted by their Foreman or Supervisor. At this
time, questions may be asked and suggestions made regarding safety issues

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What are the main steps involved in butt fusion of HDPE pipes?

Provision of EPCC Service for Sewage Water

PROJECT NAME Intake Project

PROJECT NO. 027-SC-19

PROVISION OF EPCC SERVICE FOR SEWAHE WATER INTAKE PROJECT