1
2
Thank you for selecting Georg Fischer Central Plastics’ Conventional fusion products. GFCP strives to
deliver the best technology and materials combined with rugged, durable construction to provide a
productive and reliable fusion connection for your polyethylene system.
To ensure this product lives up to all expectations, it is important to receive proper training from an
authorized instructor and to read and comply with this instruction manual before attempting to make any
butt fusion joints.
This manual is intended to provide a general introduction to the tools and steps required for making a
sound butt fusion joint. The instructions contained in this manual have been qualified to the requirements
of Title 49 Code of Federal Regulations, Part 192.283. GFCP assumes no liability in connection with the
data contained herein and all data is accepted at the user’s risk.
GFCP strongly recommends that fusion fittings be installed only by persons that have received training
from an authorized instructor, that have a strong working knowledge of polyethylene and heat fusion,
and that have demonstrated their understanding of these requirements by making fusion joints that have
been qualified by destructive testing. Persons responsible for the joining of polyethylene pipe for
regulated gas applications must qualify according to the requirements of Title 49 Code of Federal
Regulations, Part 192.285. Other regulations may also apply depending on the application, local codes,
and/or jurisdictional oversight of state and local regulating agencies.
All rights reserved, in particular the rights of duplication and distribution as well as translation. Duplication
and reproduction in any form (print, photocopy, microfilm or electronic) requires the written permission
of Georg Fischer Central Plastics, LLC.
3
Table of Contents
General Information ..................................................................................................................................... 4
Safety Notes and Warning Symbols ............................................................................................................ 5
Jobsite Preparation ...................................................................................................................................... 6
Fitting Storage and Handling ....................................................................................................................... 6
Tools and Equipment ................................................................................................................................... 7
Butt Fusion Parameters ................................................................................................................................ 7
Butt Fusion Procedure:................................................................................................................................. 9
Fusion Inspection ....................................................................................................................................... 12
Destructive Testing ..................................................................................................................................... 12
Acceptable Butt Fusion Joints: ................................................................................................................... 14
Unacceptable Butt Fusion Joints: .............................................................................................................. 14
4
General Information
Heat fusion joining procedures have varied historically from one pipe and/or fitting manufacturer to the
next. In the mid-1990's, the Plastics Pipe Institute was petitioned by the Department of Transportation,
Office of Pipeline Safety, to assist in promoting greater uniformity in joining procedures for polyethylene
pipe. As a result, a procedure was developed and qualified through industry cooperation that allowed the
use of a single procedure for butt fusion joining all products produces from commercially available
polyethylene piping material. That "generic" procedure was later published in ASTM F2620 "Standard
Practice for Heat Fusion Joining of Polyethylene Pipe and Fittings." The following procedures align with
ASTM F2620 and has been qualified in accordance with 49 CFR Part 192.283.
Proper installation techniques, installer understanding of and training to these techniques, and effective
examination before installation are all essential keys to a successful fusion joint. This document provides
detailed instructions for each key step to making a successful installation, explains why each step is
important, and describes how to tell if the requirements of each step have been accomplished. The basic
steps for a successful fusion are included in these instructions. THERE ARE NO SHORTCUTS TO THESE
INSTRUCTIONS. Failure to follow these instructions and/or failure to satisfy the basic requirements for
each step will result in a poor quality fusion.
5
Safety Notes and Warning Symbols
Safety notes are included in this manual where appropriate; however, this manual does not purport to
address all of the safety concerns associated with its use. It is the responsibility of the user of this
manual to establish appropriate safety and health practices and to determine the applicability of
regulatory limitations prior to use.
Symbols are used throughout this manual to indicate the potential for danger, injury, and/or material
damage, and to alert the user of important information related to the fusion process. Symbols indicate
that particular attention should be given and that an action is necessary.
Symbol | Meaning
Attention! – Important Information! Possible danger, damage, risk of unsuccessful fusion or
poor fusion quality.
Best Practice – This symbol is used to indicate an instruction that is considered to be a “best
practice”. This practice is highly recommended and potentially vital to success.
Prohibited! – This symbol is used to indicate a practice, material, tool, or action that is
specifically prohibited in conjunction with instructions in this manual.
Heat fusion equipment is not to be considered “explosion proof”.
Caution should be exercised when working with generators and other electrical power sources.
Facer blades have sharp edges. Use with care to avoid injury.
Tools should be in good working order and inspected before use for wear and/or damage.
Damaged or worn tools should not be used until repaired.
6
Jobsite Preparation
Wind and Precipitation: The heating tool shall be shielded in an insulated container to prevent excessive
heat loss. Shield the pipe fusion area and fusion tools from wind, snow, blowing dust, and rain by using
a canopy or similar device.
Pipe and Fitting Surface Preparation: The pipe and fitting surfaces to be joined or held in clamps shall
be dry and clean and free of ice, frost, snow, dirt and any other contamination. After preparation, the
surfaces shall be protected from contamination until joined. Contamination of the area to be fused will
cause a failed joint.
Coiled Pipe: Straighten and re-round coiled pipe before the butt fusion process. Specification D2513
requires field re-rounding of coiled pipe before joining sizes larger than 3 IPS. If curvature still exists,
align pipe ends into the machine in a "S" configuration to help gain proper alignment.
Fitting Storage and Handling
Fittings should always be stored indoors, in their original packaging, until the time of
installation.
Black fitting resin contains a 2% to 3% carbon black additive to protect against UV degradation effects.
Yellow fitting resin contains a stabilization pack that also provides some degree of protection against UV
effects. Fittings stored indoors in their original packaging have a virtually unlimited shelf life.
Fittings should be inspected for damage before installing to ensure that there is no visible damage to
fusion surfaces, and that no foreign materials are present on or near the fusion surfaces. Fittings can be
cleaned if incidental contact is made with the fusion surface. A suitable cleaning agent that contains no
additives to hinder the fusion process must be used. 90% or greater concentration of Isopropyl alcoholi
with no additional additives except water is universally accepted as a good cleaning agent. Care should
be taken that any wipes or cloths used to clean the fitting have not been used prior as contaminants
that can interfere with the process may be accidentally introduced.
Acetone has been found to be an acceptable alternative cleaning agent in situations where
isopropyl alcohol use may be restricted.
Do not clean faced surfaces to remove contamination. Reface the surfaces if they have been in
contact with contamination sources. Cleaning agents should only be used to remove visible
surface contamination such as oils or grease prior to facing.
DO NOT USE DENATURED ALCOHOL – Denatured alcohols may contain additives that can
prevent fusion and shall not be used.
A “clean” fitting has no visible debris or particles on the fusion surface. It has no body oils or other
substances that will prevent PE from fusion joining. It is not necessary that fittings are sterile to perform
as intended but some compounds that are not visible to the eye can prevent fusion.
7
Tools and Equipment
Proper tools are essential for a successful butt fusion. At minimum, the following items should be
accessible during fusion:
Heating Tools: The heating tool shall have sufficient area to adequately cover the ends of the size of
pipe to be joined. This electrical tool shall have sufficient wattage and control to maintain the specified
surface temperature of the tool faces. It shall also be equipped with heater faces that are coated with
non-stick material to prevent sticking to the pipe surface.
Butt Fusion Machine: A butt fusion machines has three basic parts. (1) a stationary clamping fixture and
a moveable clamping fixture for aligning and holding each of the two parts to be fused. This may or may
not include the power supply to operate the machine; (2) a facer for simultaneously preparing the ends
of the parts to be joined; and (3) appropriate inserts for clamping different pipe sizes or fitting shapes.
But fusion machines are operated manually or hydraulically. Some have their own power supply and
some require a separate generator. They are available in a variety of sizes to fuse pipe and tubing
produced to ASTM and other industry specifications.
Pipe Cutting Tool: When cutting a PE pipe to length before fusing, the PE pipe shall be cut using cutting
tools which do not introduce contamination to the pipe surfaces or the fusion equipment. Cutting shall
be performed using tools such as a hand saws, reciprocating saws, run-around pipe cutters, guillotine
cutters, pipe shears, chain saws. Liquid lubricants, if used (for example, bar or chain oil or other
lubricants) transferred to the pipe ends during cutting, shall be removed using 90% or greater isopropyl
alcohol and a clean cloth.
Pipe Support Stands: Optional pipe support stands or racks are used to support the pipe at both ends of
the butt fusion machine to assist with pipe loading and alignment.
Heating tools may be equipped with thermometers or other built-in temperature indicating
devices. This device indicates the internal temperature of the heating iron, which is usually
higher than the temperature of the heating tool surfaces. Use a pyrometer periodically to verify
the temperature of the tool face surface within the pipe or fitting contact area in multiple
locations to ensure uniform surface temperatures.
Butt Fusion Parameters
Heater Surface Temperature: 400°F (204°C) minimum to 450°F (232°C) maximum.
Interfacial Fusion Pressure: 60 psi (0.41MPa) minimum to 90 psi (0.62 MPa) maximum.
Correctly sized inserts for the pipe or fitting OD.
Sufficient power source to operate fusion equipment.
Heater surface temperature: Should be set as close to 425°F as possible with an overall range of 400°F
(204°C) minimum to 450°F (232°C) maximum. Heater surface temperature should be verified with a
contact pyrometer, at multiple points that will contact the pipe diameter, to be within the correct range.
Heater surfaces should have a factory applied non-stick coating, in good condition, and be clean and
free of contaminants. Heater surfaces can only be cleaned with a clean, dry, low lint, cotton towel or
rag.
8
A slight discoloration on the heater face from the pipe pigment is normal.
Any surface build up or other foreign material on the heater face is not acceptable.
Fusion gauge pressure and interfacial pressure are not the same! For hydraulically operated equipment,
the gauge pressure can be calculated by multiplying the pipe surface area by the interfacial pressure to
obtain the fusion force, then divide the fusion force by the total effective piston area of the hydraulic
cylinders. Addition of the amount of gauge pressure needed to overcome drag of the pipe is also
included in the final gauge pressure. Most fusion machine manufactures provide calculators for
determining gauge pressure when joining specific pipe diameters and DR’s.
The equation below can be useful when calculating a gauge pressure is necessary:
PG = TFP+PD Where: PG = Fusion Gauge Pressure IFP = Interfacial Pressure
TFP = (Ap X IFP) / TEPA TFP = Theoretical Fusion Pressure Ap = Pipe Surface Area
Ap =(OD – t) X t X 3.1416 TEPA = Total Effective Piston Area PD = Drag pressure
OD = Pipe Outside Diameter t = Pipe wall thickness
Manually operated machines do not require a gauge pressure calculation. When joining 4 IPS and
smaller pipe using a manual machine, apply and hold enough force to achieve a complete and uniform
rollover of the pipe fusion bead. If a force measurement is required, some hand operated manual
machines can be adapted for use with a torque wrench.
Melt Bead Size and fusion bead are not the same! The melt bead size refers to the size of the melt bead
when against the heater surface. The melt bead is the bead that determines if the ends were
sufficiently heated. Melt bead size should conform to the chart show in step 4 of the following
procedures. The fusion bead is the finished bead after the ends of the pipe have been fused.
9
Butt Fusion Procedure:
1. Clamp and Secure: Clean the inside and outside of the
pipe and/or fitting with a clean, dry, lint-free, non-
synthetic cloth, such as cotton. If contaminates cannot
be removed, wash the pipe with water and a clean
cloth, or use 90% or greater concentration of Isopropyl
alcohol or acetone and a clean cloth. Pre-saturated
alcohol wipes can also be used. Align the pipe ends in
the fusion machine before clamping, do not force
alignment with the machine clamps. Leave enough pipe
protruding through the clamps to allow for facing.
2. Face: Face the components ends until the facer stops
have been reached and the facer is locked between the
machine jaws. This will ensure parallel joining surfaces
between the components. Open the carriage and
remove the facer and all shavings and debris. Avoid
touching the components or use a clean, dry, lint free,
non-synthetic cloth such as cotton. Bring the pipe ends
together and visually verify square faced pipe ends that
are touching with no visible gaps between.
3. Align: Check the pipe ends for high-low adjustment. If
adjustment is needed, tighten the high side clamp, do
not loosen the low side clamp. Re-face the pipe ends if
adjustments are made. The maximum allowable
misalignment is 10% of the pipe minimum wall
thickness.
4. Melt: Verify the heater surface temperature is within
range with a contact surface pyrometer. If necessary,
clean the heater surface with a clean, dry, lint free, non-
synthetic cloth such as cotton. Place the heater in the
machine between the pipe ends and bring the pipe ends
into contact with the heater under full fusion
pressure/force. Briefly ensure full contact between the
components and the heater, then reduce the
pressure/force to zero (or drag pressure only on
hydraulic machines). For pipe diameters 14 inch and
larger, hold the fusion pressure until a slight melt bead is formed around the circumference of
the pipe before reducing pressure. After reducing pressure to ensure that there is no contact
force against the heater, begin the heat soak period to allow the molten polyethylene bead to
Example shown using a BS4 Butt Fusion Machine
10
form between the heater and the component ends. Continue the heat soak until the melt bead
size has developed per the table below:
For 14 IPS and larger pipe sizes, maintain the heat soak for a minimum of 4.5 minutes for every inch
(25.4mm) of pipe wall thickness and achieve minimum melt bead size.
5. Join: When the proper melt bead size is achieved,
quickly move the components away from the heating
tool, remove the heater, and quickly inspect the pipe
ends for proper melt appearance. Acceptable melt
appears flat and smooth with no unmelted areas.
Unacceptable melt appearance is any combination
of a concave surface, unmelted areas, a bubbly,
pock-marked, or sandpaper-like surface, or melted
material sticking to the heating tool surfaces.
If any of the above appearance is present,
discontinue the joining procedure, allow the
components ends to cool completely, and restart
from step 1.
Quickly bring the component ends together, apply the
correct fusion force. DO NOT SLAM the ends together.
A double fusion bead will form on the ends that will roll
over the surfaces of the component.
6. Hold: Maintain the correct joining force on the immobile fusion joint until sufficiently cooled.
Cool while under fusion force for a minimum of 11 minutes per inch (25.4mm) of wall thickness.
For ambient temperatures above 100°F (38°C) additional cooling time may be needed. Avoid
pulling, bending, or rough handling for an additional 30 minutes after removal from the fusion
machine for sizes larger than 1 IPS, for smaller sizes use 10 minutes for cooling time. Do not
Example shown using a BS4 Butt Fusion Machine
11
apply internal pressure until the joint and surrounding material are completely cooled to
ambient temperature.
7. Inspect: Visually inspect and compare the joint against the butt fusion bead visual acceptance
criteria below.
• The V-groove between the fusion beads
should not be deeper than ½ the bead height.
• The high-low difference in the component
ends should not exceed 10% of the component
wall thickness.
• The pipe ends should be aligned with no visual
miter between the component ends.
• There should be no gaps in the fusion bead
indicating incomplete facing.
• There should be no inclusions or debris in the
fusion bead.
• When butt fusing to molded fittings, the fitting-side bead may contain irregularities in
shape such as minor indentations, deflections, and non-uniform rollover. This is due to
molded part cooling and knit lines. In these cases, visual evaluation is based on the size
and shape of the pipe-side fusion bead.
Note: This procedure is suitable for use with components made from a like polyethylene material that
exhibit similar melt characteristics. This procedure can be used without change to join components of
“like” wall thickness or that do not exceed on standard DR difference, e.g. DR 11 to DR9. When
components of different DR are joined, use the fusion pressure/force for the higher DR (thinner wall)
component.
NOTICE: Fusions should not be performed by any persons who have not been trained and qualified. The
installer should demonstrate their ability to make butt fusion joints through examination and
destructive testing. Persons responsible for butt fusion joining of gas distribution piping must qualify
according to the requirements of Title 49 Code of Federal Regulations, Part 192.285.
12
Fusion Inspection
Observed Condition
Possible Cause
Excessive double bead width
Overheating: Excessive joining force
Double bead v-groove too deep
Excessive joining force; Insufficient
heating; Pressure during heating
Flat top on bed
Excessive joining force; overheating
Non-uniform bead size around pipe
Misalignment; Defective heating tool;
Worn equipment; Incomplete facing
One bead larger than the other
Misalignment; Component slipped in
clamp; Worn equipment; Defective
heating tool; Incomplete facing
Beads too small
Insufficient heating; Insufficient joining
force
Bead not rolled over to surface
Shallow v-groove – Insufficient heating
and insufficient joining force; Deep v-
groove – Insufficient heating and
excessive joining force
Beads too large
Excessive heating time
Squarish outer bead edge
Pressure during heating
Rough, sandpaper-like, bubbly, or
pockmarked melt bead surface
Hydrocarbon contamination
Third bead
Excessive joining force
Destructive Testing
A specimen joint must be:
Visually examined during and after assembly or joining and found to have the same appearance
as a joint or photographs of a joint that is acceptable under the procedure; and
In the case of heat fusion;
o Tested under any one of the test methods listed under 192.283(a), and for PE heat
fusion joints visually inspected in accordance with ASTM F2620 (incorporated by
reference, 192.7), or a written procedure that has been demonstrated to provide an
equivalent or superior level of safety, applicable to the type of joint and material being
tested;
o Examined by ultrasonic inspection and found not to contain flaws that would cause
failure, or
o Cut into at least 3 longitudinal straps, each of which is:
13
Visually examined and found not to contain voids or discontinuities on the cut surfaces of the
joint area; and Deformed by bending, torque, or impact, and failure occurs, it must not initiate
in the joint area.
For wall thickness up to 1 in.: It is possible to evaluate sample joints to verify the skill and knowledge of
the fusion operator. Cut joints into straps, and visually examine and test for bond continuity and
strength. Bending, peeling, and elongation tests are useful for this purpose. These tests generally
conducted on smaller pipe sizes. Visually inspect the cut joint for any indications of voids, gaps,
misalignment of surfaces that have not been properly bonded. Bend each sample at the fusion joint
with the inside of the pipe facing out until the ends touch. The inside bend radius should be less than
minimum wall thickness of the pipe. In order to successfully complete the bend back, a vise may be
needed. The sample must be free of cracks and separations within the fusion joint location. If failure
does occur at the weld in any of the samples, then fusion procedures should be reviewed and corrected.
A test procedure is called out in 49 CFR 192.285 Plastic Pipe: Qualifying person to make joints. This
procedure requires that a heat fusion specimen must be cut into at least 3 longitudinal straps, each of
which is: (a) visually examined and found not to contain voids or discontinuities on the cut surfaces of
the joint area; and (b) deformed bending torque, or impact, and if failures occurs, it must not initiate in
the joint area.
A person must be re-qualified under an applicable procedure once each calendar year at intervals not
exceeding 15 months, or after any production joint is found unacceptable by testing under 192.513.
For transmission pipe installed after July 1, 2021, records demonstrating each person's plastic pipe
joining qualifications at the time of construction for a minimum of 5 years following construction.
14
Acceptable Butt Fusion Joints:
Unacceptable Butt Fusion Joints:
CONCAVE MELT due to
excessive pressure during heating
Incomplete Facing
Poor Alignment
/
