ASTM F3507-21

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F3507 − 21 An American National Standard
Standard Practice for
Butt-Fusion Joining of Crosslinkable Polyethylene (CX-PE)
Pipe and Tubing
This standard is issued under the fixed designation F3507; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope butt fusion of both CX-PE pipe and tubing even when tubing
is not explicitly referred to.
1.1 This practice describes procedures for making butt
fusionjointswithcrosslinkablepolyethylene(CX-PE)pipeand
1.5 CX-PE pipe or tubing is required to produce sound
tubing which is less than 30 % crosslinked at the time of
joints when using the joining procedures described in this
joining. This practice shall not be applied to crosslinked
practice. Component ends joined in accordance with this
products, that is PEX pipe or tubing or to CX-PE after
practice shall be of the same nominal diameter and wall
commissioning (commissioning transitions CX-PE pipe into
thickness.
crosslinked pipe).
1.6 The ability to join pipe using this practice does not
NOTE 1—For avoidance of doubt, CX-PE is a completely different
imply that the pipe joined is suitable for any intended use.
product than PEX, especially for the purposes of butt-fusion joining and
1.7 This practice does not purport to address any issues
the fabrication of fittings. The two must not be confused by the reader of
this standard.
related to the commissioning of a CX-PE system prior to its
use. The intention of this standard practice is to set forth
1.2 The main difference between this practice and Practice
requirements for the butt fusion of CX-PE pipe and tubing
F2620isthattheproductiondateofpipemustbecheckedprior
whichwhenfollowedareexpectedtoyielddurablejointsinthe
to butt fusion. Field experiments have indicated that it is best
said pipe and tubing.
to make heat fused joints before the pipe has aged six months
to ensure it has not crosslinked more than 30 % at ambient
1.8 Only procedures related to butt-fusion joining are cov-
conditions. (See 7.2.)
ered in this practice. Saddle fusion and socket fusion are not
included in this practice.
1.3 Joints are made by means of butt-fusion joining in, but
not limited to, a field environment. Other suitable butt-fusion
1.9 The values stated in inch-pound units are to be regarded
joining procedures may be available from various sources
as standard. The values given in parentheses are mathematical
includingpipeandfittingmanufacturers.Thispracticedoesnot
conversions to SI units that are provided for information only
claimtoaddressallpossiblebutt-fusionjoiningproceduresand
and are not considered standard.
does not prevent the use of qualified procedures developed by
1.10 The text of this practice references notes, footnotes,
other parties that have been proven to produce reliable butt
and appendixes which provide explanatory material. These
fusion joints.
notesandfootnotes(excludingthoseintablesandfigures)shall
1.4 The parameters and procedures set forth in this practice
not be considered as requirements of the practice.
are applicable to the butt-fusion joining of CX-PE pipe and
1.11 This standard does not purport to address all of the
tubing. Consult with the manufacturers of CX-PE pipe or
safety concerns, if any, associated with its use. It is the
tubingtoensurethattheyapproveoftheuseofthispracticefor
responsibility of the user of this standard to establish appro-
butt-fusion joining of their products. This practice applies to
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
This practice is under the jurisdiction of ASTM Committee F17 on Plastic
1.12 This international standard was developed in accor-
Piping Systems and is the direct responsibility of Subcommittee F17.20 on Joining.
dance with internationally recognized principles on standard-
Current edition approved April 1, 2021. Published August 2021. DOI: 10.1520/
F3507–21
ization established in the Decision on Principles for the
A standard specification for CX-PE pipe is being developed by Subcommittee
Development of International Standards, Guides and Recom-
F17.68.
3 mendations issued by the World Trade Organization Technical
Apractice for commissioning of CX-PE piping systems is being developed by
Subcommittee F17.68. Barriers to Trade (TBT) Committee.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F3507 − 21
2. Referenced Documents same time, with the possibility of the final crosslinking taking
4 place after installation of pipe made from CX-PE compound.
2.1 ASTM Standards:
3.2.3.1 Discussion—CX-PE pipe is minimally crosslinked
D638 Test Method for Tensile Properties of Plastics
and is best butt fused before the level of crosslinking reaches
D1598 Test Method for Time-to-Failure of Plastic Pipe
30 %. When pipe made from CX-PE reaches a level of
Under Constant Internal Pressure
crosslinking ≥ 65 % it is referred to as crosslinked pipe in
D1599 Test Method for Resistance to Short-Time Hydraulic
accordance with this standard. The pipe manufacturer mea-
Pressure of Plastic Pipe, Tubing, and Fittings
sures the crosslinking level of CX-PE by performing a gel
D1600 Terminology forAbbreviatedTerms Relating to Plas-
content test.
tics
F412 Terminology Relating to Plastic Piping Systems 3.2.4 drag pressure, fusion machine (P ), n—the amount of
D
F876 SpecificationforCrosslinkedPolyethylene(PEX)Tub- pressure that needs to be applied during a butt fusion process
ing to overcome the frictional resistance in the butt fusion machine
F2620 PracticeforHeatFusionJoiningofPolyethylenePipe carriage components.
and Fittings
3.2.5 gauge pressure, fusion machine (P ), n—the pressure
G
F2634 Test Method for Laboratory Testing of Polyethylene
reading displayed on a hydraulic fusion machines pressure
(PE) Butt Fusion Joints using Tensile-Impact Method
gauge.
F3124 Practice for Data Recording the Procedure used to
3.2.5.1 Discussion—To make a durable butt fusion this
Produce Heat Butt Fusion Joints in Plastic Piping Systems
pressureisequaltothetheoreticalfusionpressureplusthedrag
or Fittings
pressure for the fusion machine.
F3183 Practice for Guided Side Bend Evaluation of Poly-
3.2.6 interfacial pressure, (IFP), n—the pressure required
ethylene Pipe Butt Fusion Joint
between the heated surfaces of two pieces of pipe necessary to
F3190 Practice for Heat Fusion Equipment (HFE) Operator
create a durable joint during butt fusion. This pressure is
Qualification on Polyethylene (PE) and Polyamide (PA)
normally 60 to 90 psi (0.41 to 0.62 MPa).
Pipe and Fittings
2.2 MIL/FED Standard: 3.2.7 theoretical fusion pressure, (TFP), n—the theoretical
US DOT Codes 49 CFR Part 192 Transportation of Natural hydraulic pressure required for a hydraulic fusion machine to
and Other Gas by Pipeline: Minimum Federal Safety make a durable joint.
Standards
3.2.7.1 Discussion—This is equivalent to the calculated
total force required to press the ends together divided by the
3. Terminology
total effective piston areas (TEPA). The total force required is
3.1 Definitions—Unless otherwise specified, definitions are
equal to the interfacial pressure (IFP) multiplied by the area of
inaccordancewithTerminologyF412,andabbreviationsarein
the end of the pipe.
accordance with Terminology F412 and Terminology D1600.
3.2.8 total effective piston area, (TEPA), n—a value pro-
3.2 Definitions of Terms Specific to This Standard:
vided by the fusion machine manufacturer to quantify the area
3.2.1 commission, v—a series of actions taken after instal-
of the hydraulic piston or pistons used to drive the pipe ends
lation to bring a new system into working condition.
toward each other.
3.2.1.1 Discussion—As it relates to CX-PE piping, this
includes crosslinking and leak testing of an installed system
4. Summary of Practice
(see manufacturers recommendations). For a CX-PE piping
4.1 The principle of butt-fusion joining of CX-PE pipe is to
system the ultimate completion of commissioning results in a
heat two prepared surfaces to a designated temperature, and
system composed of crosslinked pipe (see 3.2.2).Asystem that
then fuse them together by application of a sufficient force.
has been subjected to a commissioning process is considered
This force causes the melted materials to flow and undergo
commissioned.
intermolecular diffusion and entanglement, thereby resulting in
3.2.2 crosslinked pipe, n—pipe that is crosslinked to a
fusion.
measured level of ≥65 %.
4.2 Butt Fusion—The butt fusion procedure consists of
3.2.2.1 Discussion—At this point the pipe material is no
heating the squared ends of two pipes by holding them against
longer CX-PE because it is crosslinked to a degree where it
a heated plate, removing the heater plate when the proper melt
cannot be butt fused or melt processed.
is obtained, promptly bringing the ends together, and allowing
3.2.3 crosslinkable polyethylene, (CX-PE), n—polyethylene
the joint to cool while maintaining the appropriate applied
compound that has been chemically modified so that crosslinks
force.
will form when the pipe is exposed to heat and moisture at the
4.2.1 An appropriately sized butt fusion machine is used to
clamp, align, and face the pipe ends and to apply the specified
For referenced ASTM standards, visit the ASTM website, www.astm.org, or fusion force. See Fig. 1.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
NOTE 2—Research Report—A research report has been prepared in
Standards volume information, refer to the standard’s Document Summary page on
connection with this practice. Samples of CX-PE pipe were joined using
the ASTM website.
Available from DLA Document Services, Building 4/D, 700 Robbins Ave., butt fusion procedures at various conditions consistent with this practice
Philadelphia, PA 19111-5094, http://quicksearch.dla.mil. and were subsequently tested for joint strength. The research report is
F3507 − 21
FIG. 1 Butt Fusion
available from ASTM International Headquarters and is designated
5.4 This butt-fusion joining practice shall only be used to
RR:F17-2000.
join pipe or tubing made from compatible CX-PE compounds
and meeting the same specification dimensions for outside
5. Significance and Use
diameter and wall.
5.1 The procedures described in Section 8 are intended for
butt-fusion joining of CX-PE pipe and tubing, using suitable
6. Operator Training or Qualification
equipment and appropriate environmental control procedures.
6.1 Skill and knowledge on the part of the operator are
Appropriate controls are established on the butt-fusion joining
requiredtoobtainagoodqualityjoint.Skillandknowledgeare
process to ensure that the pipe is suitable for joining, that the
obtained by making butt fusion joints in accordance with
operator is properly trained, that adequate apparatus and
proven procedures under the guidance of trained or qualified
procedures are used, and that the process is protected from
operators.
environmental extremes. The controls are established by test-
6.2 Evaluate operator proficiency by testing sample joints.
ing butt-fusion joints, operator skills, the apparatus and the
(See Appendix X3 for guidance on testing of sample joints).
procedures used. When this practice is properly implemented,
strong pressure and leak-tight joints are produced. When joints
6.3 The party responsible for the butt-fusion joining of
made in accordance with this practice are destructively tested,
CX-PE pipe or tubing shall ensure that detailed procedures are
failures are expected to occur outside the fusion-joined area.
issued before actual joining operations begin. These proce-
5.1.1 This practice shall not be used to join PEX pipe or
duresshallbedevelopedinconjunctionwiththemanufacturers
tubing made in accordance with Specification F876 or any
of the pipe and the joining equipment used, shall take into
other PEX pipe or system specification. This practice is not
consideration applicable codes and regulations, and shall
intended to be used for pipe or tubing to be crosslinked by
include safety precautions to be followed.
radiation or by using peroxides.This practice shall not be used
6.4 When operator qualification procedures are not defined
to join CX-PE pipe that has been commissioned. CX-PE pipe
by the applicable owner or authority having jurisdiction, the
that has been commissioned is crosslinked pipe.
use of operator qualification and testing procedures in accor-
5.2 Melt characteristics, average molecular weight and mo-
dance with Practice F3190 shall be considered acceptable.
lecularweightdistributionareinfluentialfactorsinestablishing
suitable fusion parameters, therefore, consider the manufactur-
7. Pipe Qualification and Preparation
ers instructions in the use or development of a specific fusion
7.1 General—Only CX-PE pipe marked with CX-PE and
procedure.
the date of extrusion in the print string shall be butt fused in
5.3 The butt fusion procedures in this practice are suitable
accordance with this practice.
for joining CX-PE pipe and tubing that is used in pressure, low
NOTE3—CX-PEpipeshouldhaveacomprehendibledateprintedonthe
pressure,andnon-pressureapplications.Forsomeapplications,
pipe. If the butt-fusion operator requires additional information about the
qualification of the procedure by testing joints made using the
pipe they should consult with the seller of the pipe, and if the pipe seller
procedure in accordance with regulations from the authority
does not provide appropriate assistance, then they should contact the pipe
manufacturer directly. Information resources pertaining to the product or
having jurisdiction are required.
the pipe manufacturer may also be available on the internet.
7.2 Allowable Pipe Storage Time:
Supporting data have been filed at ASTM International Headquarters and may
7.2.1 CX-PE pipe is intended to be butt fused using this
be obtained by requesting Research Report RR:F17-2000. ContactASTM Customer
Service at service@astm.org. practice. Pipe to be fused in accordance with this practice shall
F3507 − 21
tolerate a minimum of six months outdoor storage under interface. A sample butt fusion joint shall be produced and
conditions like those used for the pipe manufacturers ambient tested at least once every week in accordance with butt-fusion
crosslinking testing. Consult the pipe manufacturer for the operator actively producing butt-fusion joints.
maximum storage time allowed for the pipe prior to it being
buttfused.Ifavailable,thecertificateofanalysisforthepipeto
8. Butt Fusion
bebuttfusedshallbeconsultedpriortobuttfusingCX-PEpipe
8.1 Apparatus—General Requirements:
of a particular lot to confirm the date of manufacture and
8.1.1 Heating Tool—Electric heating tools used shall be of
expected length of time the pipe is permitted to be stored
sufficient size to adequately cover the ends of the pipe being
before butt-fusion. Do not butt fuse CX-PE pipe if the pipe has
joined and shall match the fusion machines capabilities. They
been in storage for over six months in accordance with the date
shallbedesignedwithenoughwattageandelectroniccontrolto
on the print line on the pipe without consulting the pipe
maintain the specified heater face temperature required in this
manufacturer or the pipe certificate of analysis.
procedure. The range of the heater control shall be larger than
NOTE4—TheCX-PEpipespecification willhaverequirementsthatthe
the heating temperature specification (the typical control range
pipe producer establish CX-PE pipe storage life so that crosslinking tests
is50 °For28 °Caboveandbelowthemaximumandminimum
will not be required. The manufacturer of CX-PE joined using this
required heating tool surface temperatures). Electric heating
standard is required to establish that pipe they produce has a high
plates shall maintain consistent fusion temperatures when
probability of not crosslinking to >30 % in six months under reasonably
severe conditions. Longer duration storage may be approved by the
provided with an adequate power source.
manufacturer. CX-PE pipe that has been commissioned should have
8.1.2 Heating Tool Faces—Heating tools are made from
crosslinking >30 % and may not be joined by butt fusion but may be
materials such as aluminum, stainless steel, copper, or copper
joined by mechanical fittings or electrofusion.
alloys. CX-PE material is known to stick to hot metal heating
7.2.2 If the crosslinking level of CX-PE pipe determined by
surfaces. This sticking may be minimized by applying a
the pipe manufacturer prior to shipment is acceptable and the
non-stick coating to the heating surfaces or by fitting a
pipe manufacturer advises the installer that the pipe is permit-
high-temperature, non-stick fabric over the heating surfaces.
ted to be butt fused for a longer time than six months from the
The heating plate surfaces, coated or uncoated, shall be kept
date of extrusion, the installer is permitted in accordance with
clean and free of contaminants such as dirt, grease and plastic
this standard to butt fuse the pipe at any time within the
build-up, which may cause excessive sticking and create
manufacturer permitted maximum storage time.
unsatisfactory joints. Most of these contaminants are removed
NOTE 5—The CX-PE pipe manufacturer should be contacted by the
from the hot tool surfaces using a clean, dry, lint-free,
installer to coordinate delivery of the pipe to permit adequate time for the
non-synthetic cloth such as cotton. Do not use synthetic fabrics
CX-PE piping system to be installed by butt fusion after delivery.
which may char and stick to the fusion surface. Some
Preferably the installer will have up to five months after delivery to install
pigments, such as carbon black, may stain a heating surface
pipe before ambient crosslinking becomes a concern.
and cannot be easily removed; such stains will not contaminate
7.3 Cutting pipe—When cutting a CX-PE pipe to length
the joint interface.
before fusing, the CX-PE pipe shall be cut using cutting tools
8.1.3 After a period in service, non-stick coatings or fabrics
which do not introduce contamination to the pipe surfaces or
will deteriorate and become less effective. Deteriorated fabrics
the fusion equipment. Cutting shall be performed using tools
shall be replaced, and worn, scratched, or gouged non-stick
suchashandsaws,reciprocatingsaws,run-aroundpipecutters,
coatings shall be re-coated when they lose effectiveness. Heat
guillotine cutters, and pipe shears. No lubricants are permitted
fusion quality may be adversely affected by deteriorated
to be used when cutting pipe to be butt fused. In the event
non-stick surfaces. Spray-on chemicals, such as non-stick
contamination is transferred to the pipe or pipe ends during
lubricants or oils shall not be applied to heating iron surfaces
cutting, it shall be removed in accordance with the cleaning
as they will contaminate the joint.
procedure in X1.5.1. Additionally, care shall be taken so that
8.1.4 Temperature Indicator—Heating tools shall be
contamination does not transfer to fusion equipment and
equipped with a thermometer or other built-in temperature
contaminate subsequent joints.
indicating device. This device indicates the internal tempera-
NOTE 6—Use of chainsaws for cutting pipe should be avoided because
ture of the heating iron, which is usually higher than the
it is difficult to completely remove all oil and grease from a chainsaw,
temperature of the heating tool surfaces. Use a pyrometer, or
which will cause contamination of the joint surface
othertemperaturemeasuringdevice,onthefirstjointoftheday
7.4 Sample Joints—Each week, the first fusion of the day
and periodically during the day to verify the temperature of the
shall be a sample joint that is visually inspected and subjected
tool face surfaces within the pipe contact area. Select multiple
to a least one destructive mechanical test. Acceptable destruc-
checkpoints on each side to ensure uniform surface tempera-
tive mechanical tests include Test Method D638 using Type III
ture. An infrared pyrometer is calibrated by comparison to a
or Type IV tensile specimens, or Test Method D1599,or
calibrated surface pyrometer and adjusted to agree on each
Practice F3183, or Test Method F2634, or bent strap testing
heating tool.
(see Appendix X3). Acceptable destructive mechanical test
results shall be non-failure or failure outside of the joint
NOTE 7—Asignificant temperature variation, that is, cold spots, on the
heating tool surfaces may indicate a faulty heating iron which may need
to be serviced before it can be used.
A standard specification for CX-PE pipe is being developed by subcommittee
F17.68. 8.2 Butt Fusion Machine:
F3507 − 21
8.2.1 A Butt Fusion Machine has three basic parts: (1) a found by bringing the faced pipe ends within 2 in. (50 mm) of
stationary clamping fixture and a movable clamping fixture for each other and increase the pressure on the carriage until it
aligning and holding each of the two pipes to be fused; (2) a starts moving. Back off the pressure until the carriage is barely
facer for simultaneously preparing the ends of the parts to be moving and record the drag pressure in psig. The equations
joined (Note 7); and (3) appropriate inserts for clamping used to calculate for the fusion machine gauge pressure is
different pipe sizes. Butt Fusion Machines are operated manu- shown below. These equations only apply when using a
ally or hydraulically. Some have their own power supply hydraulic fusion machine.
commonly attached to the clamping fixture, and some require
P 5TFP1P (1)
G D
a separate generator. They are available in a variety of sizes to
A 3 IFP
~ !
p
fuse pipe and tubing produced to ASTM and other industry
TFP 5 (2)
TEPA
specifications.
A 5 OD 2 T T3.14 (3)
~ !
p
NOTE 8—Afacer is a rotating cutting device used to square-off the pipe
ends to obtain properly mating fusion surfaces. If so equipped, facing
where:
should continue until a positive mechanical stop on the butt fusion
P = Fusion Machine Gauge Pressure, psig
G
machine is reached.
TFP = Theoretical Fusion Pressure, psig
8.2.2 Pipe Support Stands—Optional pipe support stands or
IFP = Interfacial Pressure, 60 psig – 90 psig
racksareusedtosupportthepipeatbothendsofthebuttfusion
TEPA = Total Effective PistonArea, in. Supplied by fusion
machine to assist with pipe loading and alignment.
machine manufacturer
P = Fusion Machine Drag Pressure, psig
8.3 Setup: D
A = Pipe Area, in.
p
8.3.1 The butt fusion machinery shall be setup in accor-
OD = Pipe Outside Diameter, in.
dance with the parameters prescribed in Table 1.
T = Pipe Wall Thickness, in.
8.3.2 An interfacial pressure (IFP) of 60 psi to 90 psi (0.41
NOTE 9—Interfacial pressure is used to determine butt-fusion-joining
MPa to 0.62 MPa) (see Note 1 regarding research report) is
pressure settings for hydraulic butt fusion machines when joining specific
used to determine the force required to butt fuse the pipe
pipe diameters and DR’s. Interfacial pressure is not the gauge pressure.A
components. For manually operated fusion machines, enough slide rule or a gauge pressure calculator obtained from the machines
manufacturer can be used as a tool for the calculation.
force shall be applied to roll the bead back to the pipe surface.
A torque wrench is permitted to be used to apply the proper 8.4 Procedure:
force. 8.4.1 Clean the inside and outside of the pipe to be joined
8.3.3 For hydraulically operated fusion machines, the IFPis with a clean, dry, lint-free, non-synthetic cloth such as cotton.
multiplied by the pipe area (A ) to obtain the fusion force Remove all foreign matter from the piping component surfaces
p
required in pounds. The fusion force required is then divided where they will be clamped in the butt fusion machine. If this
by the total effective piston area (TEPA) of the fusion machine does not remove the contamination, refer to X1.5.1.
carriage to obtain the theoretical fusion pressure (TFP) (see Eq 8.4.2 Ifapplicable,placepipesupportstandsatbothendsof
2). The drag pressure (P ) is then added to the TFP to obtain the butt fusion machine and adjust the support stands to align
D
the fusion machine gauge pressure (P ) in psig required by the
the pipe with the fusion machine centerline. Install the pipes
G
machine (see Eq 1). TFPand IFPare not the same value. P is being joined in the stationary and movable clamps of the butt
D
TABLE 1 Butt Fusion Machine Setup Parameters
Setup Parameter
Required Condition
Manual Butt Fusion Machine Hydraulic Butt Fusion Machine
Set heating tool temperature and Set heating tool temperature and The surface temperature of heating tool faces must be 400 °F to 450 °F (204 °C to
heat to specified temperature heat to specified temperature 232 °C). in accordance with 8.4.5 (make sure equipment is in working order, see X1.1.)
(see Note 1 regarding research report)
Install clamp inserts Install clamp inserts Install clamping inserts to match the pipe OD being fused.
Electric power supply Electric power supply Check field generator for adequate power supply and fuel sufficient to complete the fu-
sion joint.
Manual pressure Set facing pressure As required. Observe butt fusion machine manufacturer’s instructions for setting facing
pressure.
Manual pressure Set heating pressure Observe the pipe and butt fusion machine manufacturer’s instructions for setting heating
pressures.
Manual pressure Set fusi
...