ASTM F412-23

Standard Terminology Relating to Plastic Piping Systems

SCOPE
1.1 This terminology is a compilation of definitions of technical terms used in the plastic piping industry. Terms that are generally understood or adequately defined in other readily available sources are not included.  
1.2 When a term is used in an ASTM document for which Committee F17 is responsible it is included only when judged, after review, by Subcommittee F17.91 to be a generally usable term.  
1.3 Definitions that are identical to those published by other ASTM committees or other standards organizations are identified with the committee number (for example, D20) or with the abbreviation of the name of the organization (for example, IUPAC International Union of Pure and Applied Chemistry).  
1.4 A definition is a single sentence with additional information included in notes.  
1.5 Definitions are followed by the committee responsible for the standard(s) (for example, [F17.26]) and standard numbers(s) in which they are used (for example, F714).  
1.6 Abbreviated Terminology:  
1.6.1 Abbreviated terminology is intended to provide uniform contractions of terms relating to plastic piping that have evolved through widespread common usage. The compilation in this standard has been prepared to avoid the occurrence of more than one abbreviated term for a given plastics piping term and to avoid multiple meanings for abbreviated terms.  
1.6.2 The abbreviated terminology and descriptions in this standard are intended to be consistent with usage in plastics piping and the standards under F17 jurisdiction. Other ASTM Committees may assign a different word-phrase description to the same abbreviated terminology. In such cases, the abbreviated terms in this standard shall apply to usage in F17 standards, or if widespread misunderstanding could result from conflicting abbreviated terminology descriptions, the abbreviated terminology for the word-phrase shall not be used in F17 standards.  
1.6.3 Acronyms and Initialisms—A word formed from the letters or parts of words of a longer word-phrase, usually from the initial letters or parts of the words. An Acronym is pronounced as a word, for example radar, for radio detection and ranging. An Initialism is pronounced as a series of letters, for example DOT for Department of Transportation.  
1.6.4 The Acronym or Initialism description is the origin word-phrase for the Acronym or Initialism, not a definition.  
1.7 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.

General Information

• Status: Published
• Publication Date: 30-Jun-2023
• ICS: 23.040.20 - Plastics pipes
• Technical Committee: F17 - Plastic Piping Systems
• Drafting Committee: F17.91 - Editorial and Terminology

Relations

• Refers: ASTM F891-24 - Standard Specification for Coextruded Poly(Vinyl Chloride) (PVC) Plastic Pipe With a Cellular Core
• Effective Date: 01-Apr-2024
• Refers: ASTM D2241-24 - Standard Specification for Poly(Vinyl Chloride) (PVC) Pressure-Rated Pipe (SDR Series)
• Effective Date: 01-Apr-2024
• Refers: ASTM F1473-24 - Standard Test Method for Notch Tensile Test to Measure the Resistance to Slow Crack Growth of Polyethylene Pipes and Resins
• Effective Date: 01-Apr-2024
• Refers: ASTM D2846/D2846M-24 - Standard Specification for Chlorinated Poly(Vinyl Chloride) (CPVC) Plastic Hot- and Cold-Water Distribution Systems
• Effective Date: 01-Apr-2024
• Refers: ASTM D3261-24 - Standard Specification for Butt Heat Fusion Polyethylene (PE) Plastic Fittings for Polyethylene (PE) Plastic Pipe and Tubing
• Effective Date: 01-Feb-2024
• Refers: ASTM F2623-24 - Standard Specification for Polyethylene of Raised Temperature (PE-RT) Systems for Non-Potable Water Applications
• Effective Date: 01-Feb-2024
• Refers: ASTM F714-24 - Standard Specification for Polyethylene (PE) Plastic Pipe (DR-PR) Based on Outside Diameter
• Effective Date: 01-Feb-2024
• Refers: ASTM F2769-24 - Standard Specification for Polyethylene of Raised Temperature (PE-RT) Plastic Hot and Cold-Water Tubing and Distribution Systems
• Effective Date: 01-Feb-2024
• Refers: ASTM F1733-24 - Standard Specification for Butt Heat Fusion Polyamide(PA) Plastic Fitting for Polyamide(PA) Plastic Pipe and Tubing
• Effective Date: 01-Feb-2024
• Refers: ASTM F876-24 - Standard Specification for Crosslinked Polyethylene (PEX) Tubing
• Effective Date: 01-Feb-2024
• Refers: ASTM D883-24 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2024
• Refers: ASTM F1281-24 - Standard Specification for Crosslinked Polyethylene/Aluminum/Crosslinked Polyethylene (PEX-AL-PEX) Pressure Pipe
• Effective Date: 01-Feb-2024
• Refers: ASTM F877-24 - Standard Specification for Crosslinked Polyethylene (PEX) Hot- and Cold-Water Distribution Systems
• Effective Date: 01-Feb-2024
• Refers: ASTM F2623-24e1 - Standard Specification for Polyethylene of Raised Temperature (PE-RT) Systems for Non-Potable Water Applications
• Effective Date: 01-Feb-2024
• Refers: ASTM F2623-23 - Standard Specification for Polyethylene of Raised Temperature (PE-RT) Systems for Non-Potable Water Applications
• Effective Date: 01-Dec-2023

Overview

ASTM F412-23: Standard Terminology Relating to Plastic Piping Systems is a comprehensive reference standard developed by ASTM Committee F17. The document compiles and standardizes definitions for technical terms and abbreviations widely used in the plastic piping industry. Its purpose is to ensure consistent language and understanding across ASTM documents and industry communications, thereby supporting accurate design, manufacturing, specification, installation, and testing of plastic piping systems.

This terminology standard is essential for anyone involved in the plastic piping field, including engineers, manufacturers, installers, regulators, and quality control professionals. By providing clear definitions and recognizing applicable industry acronyms and initialisms, ASTM F412-23 fosters clarity and reduces the risk of misinterpretation in technical documents and communications.

Key Topics

• Comprehensive Definitions: The standard provides precise, committee-reviewed definitions for terms used in plastic piping systems. Only terms that are not already well-defined in other authoritative sources are included.
• Abbreviated Terminology: It compiles commonly used industry contractions, acronyms, and initialisms (e.g., PEX, PVC) to avoid confusion and ensure uniformity.
• Cross-Committee References: Definitions identical to or derived from other ASTM committees or renowned organizations (such as ISO and IUPAC) are properly cited.
• Structure of Entries: Each definition is typically a single sentence, possibly accompanied by explanatory notes, the responsible committee, and references to the relevant ASTM standard where the term is used.
• International Harmonization: ASTM F412-23 aligns with internationally recognized standardization principles, supporting global adoption and harmonized trade practices.

Applications

Below are common practical uses of ASTM F412-23 in the plastic piping industry:

• Specification and Procurement: Ensures materials, pipe systems, and assemblies are specified using standardized terms, facilitating clear communication between buyers, suppliers, and contractors.
• Design Documents: Supports engineers and drafters in creating unambiguous construction and installation documents.
• Manufacturing Consistency: Guides manufacturers in product marking, labeling, and documentation, reducing variability and compliance risks.
• Quality Control and Testing: Helps inspectors, laboratories, and field technicians interpret standards and conduct acceptance testing accurately.
• Regulatory Compliance: Assists regulatory authorities by providing a reference glossary for inspection and code enforcement related to plastic piping systems.
• Training and Reference: Serves as a foundational resource for onboarding, professional development, and technical training in the piping industry.

Related Standards

ASTM F412-23 is closely interconnected with many other standards and guides that cover the broader spectrum of plastic piping materials, products, and practices. Common related standards include:

• ASTM D883: Terminology Relating to Plastics
• ASTM D1600: Abbreviated Terms Relating to Plastics
• ASTM F645: Guide for Selection, Design, and Installation of Thermoplastic Water-Pressure Piping Systems
• ASTM D1785: Specification for Poly(Vinyl Chloride) (PVC) Plastic Pipe
• ASTM F876, F877: Specifications for Crosslinked Polyethylene (PEX) Tubing Systems
• ISO 9080, ISO 12162: International standards for thermoplastic pipe and pressure applications
• Multiple others covering material properties and product testing as referenced throughout F412-23

By referencing ASTM F412-23 alongside these standards, industry professionals ensure the correct application, specification, and interpretation of terms and requirements in plastic piping projects.

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Keywords: ASTM F412-23, plastic piping systems, standard terminology, piping definitions, plastic piping standard, piping specification, piping acronyms, ASTM Committee F17, piping industry standards, plastic piping standards, international standardization.

Standards Content (Sample)

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: F412 − 23
Standard Terminology Relating to
Plastic Piping Systems
This standard is issued under the fixed designation F412; 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* 1.6.3 Acronyms and Initialisms—A word formed from the
letters or parts of words of a longer word-phrase, usually from
1.1 This terminology is a compilation of definitions of
the initial letters or parts of the words. An Acronym is
technical terms used in the plastic piping industry. Terms that
pronounced as a word, for example radar, for radio detection
are generally understood or adequately defined in other readily
and ranging. An Initialism is pronounced as a series of letters,
available sources are not included.
for example DOT for Department of Transportation.
1.2 When a term is used in an ASTM document for which
1.6.4 The Acronym or Initialism description is the origin
Committee F17 is responsible it is included only when judged,
word-phrase for the Acronym or Initialism, not a definition.
after review, by Subcommittee F17.91 to be a generally usable
1.7 This international standard was developed in accor-
term.
dance with internationally recognized principles on standard-
1.3 Definitions that are identical to those published by other
ization established in the Decision on Principles for the
ASTM committees or other standards organizations are iden-
Development of International Standards, Guides and Recom-
tified with the committee number (for example, D20) or with
mendations issued by the World Trade Organization Technical
the abbreviation of the name of the organization (for example,
Barriers to Trade (TBT) Committee.
IUPAC International Union of Pure and Applied Chemistry).
2. Referenced Documents
1.4 A definition is a single sentence with additional infor-
mation included in notes.
2.1 ASTM Standards:
C114 Test Methods for Chemical Analysis of Hydraulic
1.5 Definitions are followed by the committee responsible
Cement
for the standard(s) (for example, [F17.26]) and standard
D256 Test Methods for Determining the Izod Pendulum
numbers(s) in which they are used (for example, F714).
Impact Resistance of Plastics
1.6 Abbreviated Terminology:
D638 Test Method for Tensile Properties of Plastics
1.6.1 Abbreviated terminology is intended to provide uni-
D648 Test Method for Deflection Temperature of Plastics
form contractions of terms relating to plastic piping that have
Under Flexural Load in the Edgewise Position
evolved through widespread common usage. The compilation
D747 Test Method for Apparent Bending Modulus of Plas-
in this standard has been prepared to avoid the occurrence of 3
tics by Means of a Cantilever Beam (Withdrawn 2019)
more than one abbreviated term for a given plastics piping term
D790 Test Methods for Flexural Properties of Unreinforced
and to avoid multiple meanings for abbreviated terms.
and Reinforced Plastics and Electrical Insulating Materi-
1.6.2 The abbreviated terminology and descriptions in this
als
standard are intended to be consistent with usage in plastics
D882 Test Method for Tensile Properties of Thin Plastic
piping and the standards under F17 jurisdiction. Other ASTM
Sheeting
Committees may assign a different word-phrase description to
D883 Terminology Relating to Plastics
the same abbreviated terminology. In such cases, the abbrevi-
D907 Terminology of Adhesives
ated terms in this standard shall apply to usage in F17
D1003 Test Method for Haze and Luminous Transmittance
standards, or if widespread misunderstanding could result from
of Transparent Plastics
conflicting abbreviated terminology descriptions, the abbrevi-
D1079 Terminology Relating to Roofing and Waterproofing
ated terminology for the word-phrase shall not be used in F17
D1238 Test Method for Melt Flow Rates of Thermoplastics
standards.
1 2
This terminology is under the jurisdiction of ASTM Committee F17 on Plastic For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Piping Systems and is the direct responsibility of Subcommittee F17.91 on Editorial contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
and Terminology. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved July 1, 2023. Published July 2023. Originally approved the ASTM website.
in 1975. Last previous edition approved in 2021 as F412 – 21. DOI: 10.1520/F0412- The last approved version of this historical standard is referenced on
23. www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F412 − 23
by Extrusion Plastometer D3350 Specification for Polyethylene Plastics Pipe and Fit-
D1488 Test Method for Amylaceous Matter in Adhesives tings Materials
D1505 Test Method for Density of Plastics by the Density- F3378/F3378M Specification for Crosslinkable Polyethyl-
Gradient Technique ene (CX-PE) Pipe
D1527 Specification for Acrylonitrile-Butadiene-Styrene F3507 Practice for Butt-Fusion Joining of Crosslinkable
(ABS) Plastic Pipe, Schedules 40 and 80 (Withdrawn Polyethylene (CX-PE) Pipe and Tubing
2013) F3525/F3525M Specification Fabricated Fittings of Cross-
D1600 Terminology for Abbreviated Terms Relating to Plas- linkable Polyethylene (CX-PE)
tics F402 Practice for Safe Handling of Solvent Cements,
D1785 Specification for Poly(Vinyl Chloride) (PVC) Plastic Primers, and Cleaners Used for Joining Thermoplastic
Pipe, Schedules 40, 80, and 120 Pipe and Fittings
D2104 Specification for Polyethylene (PE) Plastic Pipe, F405 Specification for Corrugated Polyethylene (PE) Pipe
3 3
Schedule 40 (Withdrawn 2010) and Fittings (Withdrawn 2015)
D2239 Specification for Polyethylene (PE) Plastic Pipe F441/F441M Specification for Chlorinated Poly(Vinyl Chlo-
(SIDR-PR) Based on Controlled Inside Diameter ride) (CPVC) Plastic Pipe, Schedules 40 and 80
D2241 Specification for Poly(Vinyl Chloride) (PVC) F442/F442M Specification for Chlorinated Poly(Vinyl Chlo-
Pressure-Rated Pipe (SDR Series) ride) (CPVC) Plastic Pipe (SDR–PR)
D2282 Specification for Acrylonitrile-Butadiene-Styrene F449 Practice for Subsurface Installation of Corrugated
(ABS) Plastic Pipe (Withdrawn 2006) Polyethylene Pipe for Agricultural Drainage or Water
D2444 Practice for Determination of the Impact Resistance Table Control
of Thermoplastic Pipe and Fittings by Means of a Tup F628 Specification for Acrylonitrile-Butadiene-Styrene
(Falling Weight) (ABS) Schedule 40 Plastic Drain, Waste, and Vent Pipe
D2447 Specification for Polyethylene (PE) Plastic Pipe, With a Cellular Core
Schedules 40 and 80, Based on Outside Diameter (With- F645 Guide for Selection, Design, and Installation of Ther-
drawn 2010) moplastic Water- Pressure Piping Systems
D2513 Specification for Polyethylene (PE) Gas Pressure F714 Specification for Polyethylene (PE) Plastic Pipe (DR-
Pipe, Tubing, and Fittings PR) Based on Outside Diameter
D2661 Specification for Acrylonitrile-Butadiene-Styrene F771 Specification for Polyethylene (PE) Thermoplastic
(ABS) Schedule 40 Plastic Drain, Waste, and Vent Pipe High-Pressure Irrigation Pipeline Systems (Withdrawn
and Fittings 2013)
D2666 Specification for Polybutylene (PB) Plastic Tubing F876 Specification for Crosslinked Polyethylene (PEX) Tub-
(Withdrawn 2003) ing
D2680 Specification for Acrylonitrile-Butadiene-Styrene F877 Specification for Crosslinked Polyethylene (PEX) Hot-
(ABS) and Poly(Vinyl Chloride) (PVC) Composite Sewer and Cold-Water Distribution Systems
Piping F891 Specification for Coextruded Poly(Vinyl Chloride)
D2683 Specification for Socket-Type Polyethylene Fittings (PVC) Plastic Pipe With a Cellular Core
for Outside Diameter-Controlled Polyethylene Pipe and F948 Test Method for Time-to-Failure of Plastic Piping
Tubing Systems and Components Under Constant Internal Pres-
D2737 Specification for Polyethylene (PE) Plastic Tubing sure With Flow (Withdrawn 2018)
D2751 Specification for Acrylonitrile-Butadiene-Styrene F1025 Guide for Selection and Use of Full-Encirclement-
(ABS) Sewer Pipe and Fittings (Withdrawn 2014) Type Band Clamps for Reinforcement or Repair of Punc-
D2837 Test Method for Obtaining Hydrostatic Design Basis tures or Holes in Polyethylene Gas Pressure Pipe
for Thermoplastic Pipe Materials or Pressure Design Basis F1281 Specification for Crosslinked Polyethylene/
for Thermoplastic Pipe Products Aluminum/Crosslinked Polyethylene (PEX-AL-PEX)
D2846/D2846M Specification for Chlorinated Poly(Vinyl Pressure Pipe
Chloride) (CPVC) Plastic Hot- and Cold-Water Distribu- F1335 Specification for Pressure-Rated Composite Pipe and
tion Systems Fittings for Elevated Temperature Service (Withdrawn
D3035 Specification for Polyethylene (PE) Plastic Pipe (DR- 2011)
PR) Based on Controlled Outside Diameter F1417 Practice for Installation Acceptance of Plastic Non-
D3139 Specification for Joints for Plastic Pressure Pipes pressure Sewer Lines Using Low-Pressure Air
Using Flexible Elastomeric Seals F1473 Test Method for Notch Tensile Test to Measure the
D3212 Specification for Joints for Drain and Sewer Plastic Resistance to Slow Crack Growth of Polyethylene Pipes
Pipes Using Flexible Elastomeric Seals and Resins
D3261 Specification for Butt Heat Fusion Polyethylene (PE) F1488 Specification for Coextruded Composite Pipe
Plastic Fittings for Polyethylene (PE) Plastic Pipe and F1499 Specification for Coextruded Composite Drain,
Tubing Waste, and Vent Pipe (DWV)
D3309 Specification for Polybutylene (PB) Plastic Hot- and F1545 Specification for Plastic-Lined Ferrous Metal Pipe,
Cold-Water Distribution Systems Fittings, and Flanges
F412 − 23
F1668 Guide for Construction Procedures for Buried Plastic F2968/F2968M Specification for Crosslinked Polyethylene
Pipe (PEX) Pipe for Gas Distribution Applications
F1733 Specification for Butt Heat Fusion Polyamide(PA)
2.2 ISO Standards:
Plastic Fitting for Polyamide(PA) Plastic Pipe and Tubing
ISO 3 Preferred Numbers
F1760 Specification for Coextruded Poly(Vinyl Chloride)
ISO 497 Preferred Numbers
(PVC) Non-Pressure Plastic Pipe Having Reprocessed- ISO 12162 Thermoplastic materials for pipes and fittings for
Recycled Content pressure applications – Classification, designation and
F1924 Specification for Plastic Mechanical Fittings for Use design coefficient
on Outside Diameter Controlled Polyethylene Gas Distri- ISO R 161 Pipes of Plastics Materials for the Transport of
Fluids (Outside Diameters and Nominal Pressures) Part I,
bution Pipe and Tubing
Metric Series
F1948 Specification for Metallic Mechanical Fittings for
ISO 9080 Thermolplastics Pipes for the Transport of Fluids-
Use on Outside Diameter Controlled Thermoplastic Gas
Methods of Extrapolation of Hydrostatic Stress Rupture
Distribution Pipe and Tubing
Data to Determine the Long-Term Hydrostatic Strength of
F1970 Specification for Special Engineered Fittings, Appur-
Thermoplastic Pipe Materials
tenances or Valves for use in Poly (Vinyl Chloride) (PVC)
or Chlorinated Poly (Vinyl Chloride) (CPVC) Systems 2.3 ANSI Standard:
Z17.1 ANSI Preferred Numbers
F1973 Specification for Factory Assembled Anodeless Ris-
ers and Transition Fittings in Polyethylene (PE) and
2.4 PPI Standard:
Polyamide 11 (PA11) and Polyamide 12 (PA12) Fuel Gas
PPI TR-4
Distribution Systems
3. Terminology
F1986 Specification for Multilayer Pipe Type 2, Compres-
sion Fittings, and Compression Joints for Hot and Cold
acceptance testing—testing performed on a product to deter-
Drinking-Water Systems (Withdrawn 2020)
mine whether or not an individual lot of the product
F1987 Specification for Multilayer Pipe Type 2, Compres-
conforms with specified requirements. [F17]
sion Fittings, and Compression Joints for Hydronic Heat-
DISCUSSION—The number of requirements are usually fewer than for
ing Systems (Withdrawn 2020)
qualification testing (see definition).
F2145 Specification for Polyamide 11 (PA 11) and Poly-
acetal plastics, n—highly crystalline linear thermoplastic ho-
amide 12 (PA12) Mechanical Fittings for Use on Outside
mopolymers or copolymers characterized by repeating
Diameter Controlled Polyamide 11 and Polyamide 12 Pipe
oxymethylene units. [F17]
and Tubing
acrylonitrile-butadiene-styrene (ABS) pipe and fitting plas-
F2158 Specification for Residential Central-Vacuum Tube
tics —plastics containing polymers or blends of polymers, or
and Fittings
both, in which the minimum butadiene content is 6%, the
F2160 Specification for Solid Wall High Density Polyethyl-
minimum acrylonitrile content is 15 %, the minimum sty-
ene (HDPE) Conduit Based on Controlled Outside Diam-
rene or substituted styrene content, or both, is 15 %, and the
eter (OD)
maximum content of all other monomers is not more than
F2176 Specification for Mechanical Couplings Used on
5 %; plus lubricants, stabilizers, and colorants. [F17.61]
Polyethylene Conduit, Duct and Innerduct
D1527, D2282 [17.62] D2680, D2751
F2206 Specification for Fabricated Fittings of Butt-Fused
Polyethylene (PE)
adhesive—a substance capable of holding materials together
F2389 Specification for Pressure-rated Polypropylene (PP)
by surface attachment. [F17]
Piping Systems
adhesive bonded joint—see joint, adhesive bonded.
F2623 Specification for Polyethylene of Raised Temperature
adhesive, solvent—see solvent cement.
(PE-RT) Systems for Non-Potable Water Applications
adiabatic extrusion—a method of extrusion in which, after
F2769 Specification for Polyethylene of Raised Temperature
the extrusion apparatus has been heated sufficiently by
(PE-RT) Plastic Hot and Cold-Water Tubing and Distri-
conventional means to plastify the material, the extrusion
bution Systems
process can be continued with the sole source of heat being
F2788/F2788M Specification for Metric and Inch-sized
the conversion of the drive energy, through viscous resis-
Crosslinked Polyethylene (PEX) Pipe
tance of the plastic mass in the extruder. [D20] D883
F2818 Specification for Specification for Crosslinked Poly-
aging, n—
ethylene (PEX) Material Gas Pressure Pipe and Tubing
(1) the effect on materials of exposure to an environment
F2829/F2829M Specification for Metric- and Inch-Sized
for an interval of time.
Fittings for Crosslinked Polyethylene (PEX) Pipe
F2905/F2905M Specification for Crosslinked Polyethylene
(PEX) Line Pipe For Oil and Gas Producing Applications
Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
F2929 Specification for Crosslinked Polyethylene (PEX)
4th Floor, New York, NY 10036, http://www.ansi.org.
Tubing of 0.070 in. Wall and Fittings for Radiant Heating 5
Available from Plastics Pipe Institute (PPI), 105 Decker Court, Suite 825,
Systems up to 75 psig Irving, TX 75062, http://www.plasticpipe.org.
F412 − 23
(2) the process of exposing materials to an environment for envelope or filter materials where used during insulation.
an interval of time. [D20] D883 [F17.65] F449, F1668
alloy, n—in plastics, two or more immiscible polymers united, bedding, v—placement of support materials for buried pipe.
usually by another component, to form a plastic resin having [F17]
enhanced performance properties. [D20] D883
bell-and-spigot joint—see joint, bell-and-spigot gasket.
allowable stress—The maximum force per unit area that may
bell end—the enlarged portion of a pipe that resembles the
be safely applied to a pipe.
socket portion of a fitting and that is intended to be used to
DISCUSSION—In Guide F645, the allowable stress is determined by
make a joint. [F17]
multiplying the hydrostatic design stress (HDS) at 73°F by the
temperature correction factor. [F17.61] F645
bend—a fitting either molded separately or formed from pipe
for the purpose of accommodating a directional change.
antioxidant, n—compounding ingredient used to retard dete-
[F17]
rioration caused by oxidation. [F17]
DISCUSSION—Also called ell, elbow, or sweep. Bends generally imply
apparent density—the weight per unit volume of a material fittings of relatively shorter radii than sweeps.
including voids inherent in the material as tested. [F17]
beveled pipe—a pipe with an end chamfered to mate or adjust
DISCUSSION—The term bulk density is commonly used for material
to another surface or to assist in assembly. [F17]
such as molding powder.
approving authority—the individual official, board, binder, n—in a reinforced plastic, the continuous phase which
holds together the reinforcement. [D20] D883
department, or agency established and authorized by a state,
county, city, or other political subdivision, created by law to DISCUSSION—During fabrication, the binder, which may be either
thermoplastic or thermoset, usually undergoes a change in state.
administer and enforce specified requirements.
artificial weathering—exposure to laboratory conditions, blinding—the placement of soil, bedding material over and on
the sides of the pipe, tubing or envelope to ensure proper
which may be cyclic, involving temperature, relative
humidity, radiant energy, or any other conditions or pollut- grade, alignment, support, and protection of pipe during
backfilling and after installation. [F17.65] F449
ants found in the atmosphere in various geographical areas;
or both. [F17]
blister, n—an imperfection, a rounded elevation of the surface
DISCUSSION—The interlaboratory exposure conditions are usually
of a plastic, with boundaries that may be more or less sharply
intensified beyond those encountered in actual outdoor exposure in an
defined, somewhat resembling in shape a blister on the
attempt to achieve an accelerated effect.
human skin. [D20] D883
backfill—all material used to fill the trench from bedding to
finished surface. [F17.65 ] F449, F1668
bloom, n—a visible exudation or efflorescence on the surface
of a material. [D20] D883
backfill, final—material used to fill the trench from initial
backfill to finished surface. [F17]
blow molding—a method of fabrication in which a heated
parison (hollow tube) is forced into the shape of a mold
backfill, initial—material used to fill the trench from top of
cavity by internal gas pressure. [D20] D883
bedding to a designated height over the pipe. [F17]
blowing agent—a compounding ingredient used to produce
backfill, pipe zone—see pipe zone backfill.
gas by chemical or thermal action, or both, in manufacture of
backfill, unconsolidated—noncompacted material in place in
hollow or cellular articles. [D20] D883
trench. [F17]
brittle failure—a pipe failure mode which exhibits no visible
bead-up cycle, n—part of the fusion procedure that insures
(to the naked eye) permanent material deformation
complete contact between the heater surfaces and the pipe
(stretching, elongation, or necking down) in the area of the
ends by applying pressure such as fusion joining pressure to
break. [F17.40] F1473
force the pipe ends against the heater surfaces.
building drain—that part of the lowest horizontal piping of a
DISCUSSION—The bead-up cycle begins at initial contact of the pipe
drainage system that receives the discharge from soil, waste,
ends against the heater and ends when an indication of melt (slight melt
and other drainage pipes inside the walls of the building and
bead) is observed around the pipe circumference.
conveys it to the building sewer beyond the foundation walls
beam loading—the application of a load to a pipe between two
of the building or structure. [F17]
points of support, usually expressed in newtons (or pounds-
DISCUSSION—The building sewer generally begins 2 to 5 ft beyond
force) and the distance between the centers of the supports.
the foundation walls.
[F17]
building drain (sanitary)—a building drain that conveys gray
bedding, n—materials placed in the bottom of the trench on
water or sewage, or both. [F17]
top of the foundation soil which provides stable bottom
support for buried pipe including the trench bottom groove building drain (storm)—a building drain that conveys storm
support angle or select material placed around the pipe, and water only. [F17]
F412 − 23
building sanitary sewer—that part of the horizontal piping of trolled and where the wall thickness is usually small when
a sanitary drainage system which extends from the building compared to the diameter. [F17.25] F2158
sanitary drain, receives the discharge of the building sanitary
chalking, n—in plastics, a powdery residue on the surface of a
drain, and conveys it to a public sewer, private sewer,
material resulting from degradation or migration of an
individual sewage disposal system, or other point of
ingredient, or both. [D20] D883
disposal. [F17]
DISCUSSION—Chalking may be a designed-in characteristic.
building storm sewer—that part of the horizontal piping of a
chamfered pipe—a pipe with a conical surface (angle) made
storm drainage system which extends from the building
by cutting off the edge around the outside diameter on the
storm drain, receives the discharge of the building storm
end of a pipe.
drain, and conveys it to a public storm sewer, private storm
DISCUSSION—To assist in assembly, of socket joining, (solvent
sewer, or other point of disposal. [F17]
cementing, gasketed, and socket fusion) burrs on the pipe OD are
removed by chamfering. Refer to product manufacturer’s recommen-
building supply—See water service.
dations. [F17]
bulk factor, n—the ratio of the volume of a given mass of
molding material to its volume in the molded form.
ISO/[D20] D883
DISCUSSION—The bulk factor is also equal to the ratio of the density
of the material to its apparent density in the unmolded form.
burst strength—the internal pressure required to cause a pipe
or fitting to fail. [F17]
DISCUSSION—This pressure will vary with the rate of buildup of the
pressure and the time during which the pressure is held.
butt-fused joint—see joint, butt-fused.
butylene plastics—plastics based on resins made by the
polymerization of butene or copolymerization of butene with
one or more unsaturated compounds, the butene being in
FIG. 1 Chamfered Pipe
greatest amount by weight. [D20] D883
categorized required strength , CRS , n—one of a series
θ,t θ,t
chemical cleaner—see cleaner, chemical.
of classifications for the 97.5 % lower confidence limit,
σ , of the predicted long-term hydrostatic strength of a
LPL
chemical resistance—the ability to resist chemical attack.
plastic compound determined in accordance with ISO 9080
[F17]
and ISO 12162, expressed in MPa at a temperature, θ, in °C
DISCUSSION—The attack is dependent on the method of test and its
other than 20 °C and a time, t, in years. [F17]
severity is measured by determining the changes in physical properties.
Time, temperature, stress, and reagent may all be factors that affect the
cell, n—a small cavity surrounded partially or completely by
chemical resistance of a material.
walls. [D20] D883
chemically formed polymeric material—a cellular material
cell, closed—a cell totally enclosed by its walls and hence not
in which the cells are formed by gases generated from
interconnecting with other cells. (See also cell and cell,
thermal decomposition or other chemical reaction. [D20]
open.) ISO/[D20] D883
D883
cell, open—a cell not totally enclosed by its walls and hence
chlorinated poly(vinyl chloride) plastics—plastics based on
interconnecting with other cells. (See also cell and cell,
chlorinated poly(vinyl chloride) in which the chlorinated
closed.) [D20] D883
poly(vinyl chloride) is in the greatest amount by weight.
[D20] D883
cellular plastic—a plastic containing numerous cells, inten-
tionally introduced, interconnecting or not, distributed
chlorofluorocarbon plastics—plastics based on polymers
throughout the mass. [D20] D883 [17.63] F628 [17.25]
made with monomers composed of chlorine, fluorine, and
F891
carbon only. ISO/ [D20] D883
cellulose acetate butyrate (CAB) plastics—plastic made by
chlorofluorohydrocarbon plastics, n—plastics based on poly-
compounding a cellulose acetate butyrate ester with plasti-
mers made with monomers composed of chlorine, fluorine,
cizers and other ingredients. Cellulose acetate butyrate ester
hydrogen, and carbon only. ISO/[D20] D883
is a derivative of cellulose (obtained from cotton or wool
cleaner, chemical—an organic solvent used to remove foreign
pulp, or both) made by converting some of the hydroxyl
matter from the surface of plastic pipe and fittings. [F17.20]
groups in cellulose to acetate and butyrate groups with
F402
chemicals. [F17]
DISCUSSION—Cleaners have essentially no effect on the plastic
central vacuum tubing, n—plastic tubing used for residental
surface being cleaned and may be used prior to joining with a solvent
central vacuum systems in which outside diameter is con- cement or adhesive.
F412 − 23
cleaner, mechanical—an abrasive material or device used to (3 ) the buckling or flattening of a plastic rehabilitation liner;
remove foreign matter and gloss from the surface of plastic (4) the buckling or crushing of a plastic pipe from external
pipe and fittings. [F17] forces, such as earth loads or external hydrostatic load. [F17]
DISCUSSION—Mechanical cleaners may be used prior to joining with
compaction, soil—act of packing soil with mechanical force to
a solvent cement or adhesive.
increase its density. [F17]
closed-cell cellular plastics—cellular plastics in which almost
compatible—(1) a condition wherein components of a plastic
all the cells are noninterconnecting. [D20] D883 [F17.63]
piping system or different specific plastic materials, or both,
F628
can be joined together for satisfactory joints. (2) in relation
closed-cell foamed plastics—See closed-cell cellular plastics.
to elastomeric seal joints, a condition wherein the elastomer
does not adversely affect the pertinent properties of the
code—(1) a system of symbols, letters or numbers, used to
plastic pipe or fittings, or both, when the sealing gasket is in
convey a message requiring brevity; (2) a set of rules
intimate contact with the plastic for a prolonged period.
established by a legal or quasi-legal body. [F17]
[F17]
code, classification—a code that identifies a plastic material
composite pipe—pipe consisting of two or more different
by its properties in accordance with the pertinent ASTM
materials arranged with specific functional purpose to serve
specification. [F17]
as pipe. [F17]
code, manufacturer’s—a code that provides manufacturing
compound, n—a mixture of a polymer with other ingredients
identity for a piping product. [F17]
such as fillers, stabilizers, catalysts, processing aids,
code, thermoplastic pipe material designation— letters and
lubricants, modifiers, pigments, or curing agents. [F17.11]
ciphers for the designation of stress-rated thermoplastic
F1488, F1499
compound, which consists of two or more characters to
indicate the abbreviation as listed in Terminology D1600, for compression fitting joint—see joint, compression fitting.
the type of thermoplastic resin—followed by four or five
compression gasket joint—see joint, compression gasket.
Arabic numerals—two or three to describe the short-term
properties, in accordance with the ASTM standard being
compression molding—the method of molding a material
referenced, and two to designate the hydrostatic design stress
already in a confined cavity by applying pressure and usually
when tested in water at 73°F (23°C) in units of 100 psi, with
heat. [D20] D883
any decimal figures dropped. [F17]
conduit, (duct), n—a tubular raceway for carrying electric
DISCUSSION—In some ASTM standards, the short-term properties
wires, cables, or other conductors. [F17.10] F2176 [F17.26]
with more than two numbers have a table provided to convert to two
numbers to be used in the code. F2160
DISCUSSION—When the hydrostatic design stress code is less than two
consolidation—reduction in volume of soil as a result of
numbers, a zero is inserted before the number.
gravitational forces. [F17]
DISCUSSION—For polyethylene compound, the short-term properties
contamination—the presence of a substance not intentionally
are described using two Arabic numerals in accordance with Specifi-
incorporated in a product. [F17]
cation D3350, specifically, the cell classification number value for
density followed by the cell classification number value for slow crack
continuous waste—a drain connecting two or more plumbing
growth resistance.
fixtures or components of plumbing fixtures to a common
DISCUSSION—For crosslinked polyethylene (PEX) materials, the
trap. [F17]
short-term properties are described using two Arabic numerals in
accordance with Specification F876, specifically, a digit for chlorine
cool time at fusion pressure, (minimum), n—the minimum
resistance performance followed by a digit for UV resistance perfor-
duration that fusion pressure is maintained while the joined
mance.
pipe faces drop in temperature and solidify.
coextrusion—a process whereby two or more heated or
coupon, n—a piece or portion of a sample used to make a
unheated plastic material streams forced through one or
specimen.
more shaping orifice(s) become one continuously formed
piece. [F17.63] D2661, F628 [F17.25] F891, F1760
crack—any narrow opening or fissure in the surface that is
[F17.11] F1488
visible to the naked eye. [F17.65] F405
cold flow—See creep.
crater, n—a small, shallow surface imperfection. [D20] D883
cold molding—a special process of compression molding in
crazing, n—apparent fine cracks at or under the surface of a
which the molding is formed at room temperature and
plastic. [D20] D883
subsequently baked at elevated temperatures. [D20] D883
DISCUSSION—The crazed areas are composed of polymeric material
of lower density than the surrounding matrix.
collapse, n—(1) inadvertent densification of cellular material
during manufacture resulting from breakdown of cell struc- creep, n—the time-dependent part of strain resulting from
ture; (2) the buckling of the inner liner of composite piping; stress, that is dimensional change caused by the application
F412 − 23
of load over and above the elastic deformation and with density, apparent—see apparent density.
respect to time. [D20] D883, [17.60] F1025
density of plastics—the weight per unit volume of material at
3 3
cross laminate—a laminate in which some of the layers of
23°C expressed as D23c, g/cm (kg/m ). [F17]
material are oriented approximately at right angles to the
DISCUSSION—Taken from Test Method D1505.
remaining layers with respect to the grain or strongest
depth, n—in the case of a beam, the dimension parallel to the
direction in tension. (See also parallel laminate.) [D20]
direction in which the load is applied. [D20] D883
D883
diffusion—the movement of a material such as a gas or liquid,
crosslinkable polyethylene (CX-PE), n—a polyethylene com-
in the body of a plastic. [F17]
pound that has been chemically modified such that exposure
DISCUSSION—If the gas or liquid is absorbed on one side of a piece of
to defined conditions of time, temperature, moisture, and
plastic and given off on the other side, the phenomenon is called
pressure, which are intended to be fulfilled after installation
permeability. Diffusion and permeability are not due to holes or pores
will result in the material meeting the physical requirements
in the plastic.
of crosslinked polyethylene (PEX). [F17] F3378/F3378M,
F3507, F3525/F3525M
dimension ratio (DR)—the average specified diameter of a
pipe or tubing divided by the minimum specified wall
crosslinked polyethylene (PEX), n—a polyethylene material
thickness. The DR values shall be rounded to the nearest 0.5
that has undergone a change in molecular structure through
unless otherwise specified. [F17.10] D2683, D3261, F1733
processing whereby a majority of the polymer chains are
[17.11] D1488 [F17.26] D2737, [F17.60] D2513
chemically linked. [F17] F876, F1281, F2788/F2788M,
DISCUSSION—Each pipe can have two dimension ratios depending on
F2818, F2829/F2829M, F2905/F2905M, F2929, F2968/
whether the outside or inside diameter is used. In practice, the outside
F2968M
diameter is used if the standards requirement and manufacturing control
are based on this diameter. The inside diameter is used when this
crosslinking, n—the formation of a three dimensional polymer
measurement is the controlling one.
by means of interchain reactions resulting in changes in
physical properties. [D20] D883
drag pressure (psi), n—the fusion machine’s hydraulic pres-
sure required to overcome the static and dynamic resistance
cure, v—to change the properties of a polymeric system into a
to motion of the movable carriage.
more stable, usable condition by the use of heat, radiation, or
reaction with chemical additives. ISO/[D20] D883
dry-blend, n—dry compound prepared without fluxing or
DISCUSSION—Cure may be accomplished, for example, by removal of
addition of solvent (also called powder blend). [D20] D883
solvent or by crosslinking.
ductile failure—a pipe failure mode which exhibits material
deadload—the static load imposed on the top of the pipe.
deformation (stretching, elongation, or necking down) in the
[F17]
area of the break. [F17]
deburred pipe—a pipe with the sharp edge and/or cutting
elastomer, n—a macromolecular material that at room tem-
remnants removed from the pipe end ID or OD edges.
DISCUSSION—Pipe cutting can result in burrs and shavings at the pipe perature returns rapidly to approximately its initial dimen-
ID and OD edges. Sharp edges and cutting remnants can interfere with
sions and shape after substantial deformation by a weak
flow or joining. For socket joining, (solvent cementing, gasketed and
stress and release of the stress. [D20] D883
socket fusion) burrs on the pipe OD are removed by chamfering. Refer
to product manufacturers recommendations. [F17]
elastomeric seal—a material or device that uses an elastomer
to effect a seal between separable piping components. [F17]
elevated temperature testing—tests on plastic pipe above
23°C (73°F). [F17]
embedment—the placement of materials completely around
the pipe to provide support. [F17.62] F1668
encasement, n—see incasement, n.
encasement, v—see incasement, v.
FIG. 2 Deburred Pipe engineering plastics, n—those plastics and polymeric compo-
sitions for which well-defined properties are available, such
that engineering rather than empirical methods can be used
deflection temperature—the temperature at which a specimen
for design and manufacture of products requiring definite
will deflect a given distance at a given load under prescribed
and predictable performance in structural applications over a
conditions of test. (See Test Method D648.) Formerly called
substantial temperature range. [D20] D883
heat distortion. [F17]
degradation, n—a deleterious change in chemical structure, envelope, drainage—the materials completely surrounding a
physical properties, or appearance of a plastic. [D20] D883 pipe to provide support or protection or act as a filter. [F17]
F412 − 23
nated with the prefix FEP. Other prefixes may be adopted to designate
environmental stress cracking—the development of cracks in
other fluorocarbon plastics.
a material that is subjected to stress or strain in the presence
of specific chemicals. [F17]
fluorohydrocarbon plastics, n—plastics based on polymers
made with monomers composed of fluorine, hydrogen, and
ethylene plastics, n—plastics based on polymers of ethylene or
carbon only. ISO/[D20] D883
copolymers of ethylene with other monomers, the ethylene
being in greatest amount by mass. ISO/[D20] D883
fluoroplastic, n—a plastic based on polymers made from
monomers containing one or more atoms of fluorine, or
exfiltration, pipe—the passage of fluid from a pipe section
copolymers of such monomers with other monomers, the
through small holes or leaks. [F17]
fluorine-containing monomer(s) being in the greatest amount
expandable plastic, n—a plastic in a form capable of being
by mass. [D20] D883
made cellular by thermal, chemical, or mechanical means.
DISCUSSION—For specific examples of fluoroplastic see fluorocarbon
[D20] D883 plastic, chlorofluorocarbon plastics, fluorohydrocarbon plastics,
and chlorofluorohydrocarbon plastic.
expanded plastics—See cellular plastics.
foamed plastics, n—See cellular plastics (the preferred termi-
extrusion, n—a process in which heated or unheated plastic is
nology).
forced through a shaping orifice (a die) in one continuously
forming, n—a process in which the shape of plastic pieces
formed shape as film, sheet, rod, or tubing. [D20] D883
such as sheets, rods, or tubes is changed to a desired
extrusion, adiabatic—see adiabatic extrusion.
configuration. [D20] D883
DISCUSSION—The use of the term “forming” in plastics technology
fabricating, n—the manufacture of plastic products from
does not include such operations as molding, casting, or extrusion, in
molded parts, rods, tubes, sheeting, extrusions, or other
which shapes or pieces are made from molding materials or liquids.
forms by appropriate operations such as punching, cutting,
frosting, n—a light-scattering surface resembling fine crystals.
drilling, and tapping including fastening plastic parts to-
See also chalking, haze, bloom. [F17]
gether or to other parts by mechanical devices, adhesives,
heat sealing, or other means. [D20] D883
fungi resistance—the ability of plastic pipe to withstand fungi
growth or their metabolic products, or both, under normal
failure, adhesive—rupture of an adhesive bond, such that the
conditions of service or laboratory tests simulating such
plane of separation appears to be at the adhesive-adherend
conditions. [F17]
interface. [F17]
fuse, v—(1) to convert plastic powder or pellets into a
failure, brittle—see brittle failure
homogeneous mass through heat and pressure; (2) to make a
failure, ductile—see ductile failure
plastic piping joint by heat and pressure. [F17]
failure, slit —see silt failure
fusion cycle, n—the pressure / time sequence, at a defined
heater surface temperature for the fusion procedure, begin-
filler, n—a relatively inert material added to a plastic to modify
ning with the bead-up cycle and ending when the cooling
its strength, permanence, working properties, or other quali-
time is complete.
ties or to lower costs. (See also reinforced plastic.) [D20]
D883
fusion machine operator, n—a trained person qualified to
perform fusion joining of plastic pipes and/or fittings based
fish-eye, n—small globular mass that has not blended com-
on a fusion procedure.
pletely into the surrounding material. [D20] D883
fusion pressure (psi), n—for machines with hydraulic pressure
fitting, n—a piping component used to join or terminate
capability, this is a calculated number determined by adding
sections of pipe or to provide changes of direction or
the theoretical fusion pressure (psi) and the drag pressure
branching in a pipe system. [F17]
(psi).
flanged joint—see joint, flanged.
DISCUSSION—This is the gauge pressure used by the butt fusing
flare joint—see joint, flare.
operator on the butt fusing machine to join the pipe ends.
flow rate—rate of extrusion, weight per unit of time, g/10 min
fusion procedure, n—a written document that provides de-
(kg/s), of molten resins through a die of specified length and
tailed steps for performing fusion joining that has been
diameter, under prescribed conditions of temperature, load,
qualified by testing.
and piston position in the barrel as the timed measurement is
being made. [F17]
gasket joint—see joint, compression gasket and joint, bell-
and-spigot gasket.
fluorocarbon plastic, n—a plastic based on polymers made
gate, n—in an injection mold, a constriction in the flow channel
with perfluoromonomers. ISO/[D20] D883
between the runner and the mold cavity. [D20] D883
DISCUSSION—When the monomer is essentially tetrafluoroethylene,
the prefix TFE is sometimes used to designate these materials. It is
gel, n—(1) a semisolid system consisting of a network of solid
preferable to use the accepted abbreviation, PFTE. TFE should not be
aggregates in which liquid is held; (2) the initial jelly-like
used by itself to mean PTFE. When the resins are copolymers of
tetrafluoroethylene and hexafluoropropylene, the resins may be desig- solid phase that develops during the formation of a resin
F412 − 23
from a liquid; (3) with respect to vinyl plastisols, gel is a gravity flow, pressure, n—gravity flow of liquefied medium in
state between liquid and solid that occurs in the initial stages a pressure-rated piping system where flow regularly fills the
of heating, or upon prolonged storage. [D20] D883 piping system (closed channel flow) and subjects the piping
DISCUSSION—All three types of gel have very low strengths and do system to internal hydrostatic pressure that is within the
not flow like a liquid. They are soft, flexible, and may rupture under
capabilities of pressure-rated piping system components and
their own weight unless supported externally.
joints. [F17]
gel point—the stage at which a liquid begins to exhibit
gray water—the waste water of a system that may be a
pseudo-elastic properties. [D20] D883 combination of the liquid and water-carried wastes except
DISCUSSION—This stage may be conveniently observed from the human wastes. [F17]
inflection point on a viscosity-time plot. (See gel (2).)
groove angle—the angle of support for a pipe when a formed
gel time, n—the period of time from the initial mixing of the groove is made in bedding or foundation. [F17]
reactants of a liquid material composition to the time when
gusset, n—
gelation occurs, as defined by a specific test method. [D20]
(1) a piece used to give additional size or strength in a
D883
particular location of an object.
DISCUSSION—For a material that must be processed by exposure to
(2) the folded-in portion of flattened tubular film. [D20]
some form of energy, the zero time is the start of exposure.
D883
glass transition—the reversible change in an amorphous
haunching—the act of placing bedding material around the
polymer or in amorphous regions of a partially crystalline
haunch of the pipe. [F17]
polymer from (or to) a viscous or rubbery condition to (or
haunch—that portion of the pipe barrel extending from bottom
from) a hard and relatively brittle one. [D20] D883
to springline. [F17]
DISCUSSION—The glass transition generally occurs over a relatively
narrow temperature region and is similar to the solidification of a liquid
haze—the cloudy or turbid aspect or appearance of an other-
to a glassy state; it is not a phase transition. Not only do hardness and
wise transparent specimen caused by light scattered from
brittleness undergo rapid changes in this temperature region but other
within the specimen or from its surfaces. [D20] D883
properties, such as thermal expansibility and specific heat also change
DISCUSSION—For the purpose of Test Method D1003, haze is the
rapidly. This phenomenon has been called second order transition,
percentage of transmitted light which, in passing through the specimen,
rubber transition, and rubbery transition. The word transformation has
deviates from the incident beam through forward scatter more than 2.5°
also been used instead of transition. Where more than one amorphous
on the average.
transition occurs in a polymer, the one associated with segmental
motions of the polymer backbone chain or accompanied by the largest
heat-fused joint—see joint, heat-fused.
change in properties is usually considered to be the glass transition.
heat joining—making a joint by heating the mating surfaces of
the pipe components to be joined and pressing them together
glass transition temperature (Tg)—the approximate mid-
so that they fuse and become essentially one piece. [F17]
point of the temperature range over which the glass transi-
DISCUSSION—Also known as heat fusion, thermal fusion, and fusion.
tion takes place. [D20] D883
DISCUSSION—The glass transition temperature can be determined
heat mark—extremely shallow depression or groove in the
readily only by observing the temperature at which a significant change
surface of a plastic visible because of a sharply defined rim
takes place in a specific electrical, mechanical, or other physical
or a roughened surface. (See also sink-mark. ) [D20] D883
property. Moreover, the observed temperature
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F412 − 21 F412 − 23
Standard Terminology Relating to
Plastic Piping Systems
This standard is issued under the fixed designation F412; 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*
1.1 This terminology is a compilation of definitions of technical terms used in the plastic piping industry. Terms that are generally
understood or adequately defined in other readily available sources are not included.
1.2 When a term is used in an ASTM document for which Committee F17 is responsible it is included only when judged, after
review, by Subcommittee F17.91 to be a generally usable term.
1.3 Definitions that are identical to those published by other ASTM committees or other standards organizations are identified with
the committee number (for example, D20) or with the abbreviation of the name of the organization (for example, IUPAC
International Union of Pure and Applied Chemistry).
1.4 A definition is a single sentence with additional information included in notes.
1.5 Definitions are followed by the committee responsible for the standard(s) (for example, [F17.26]) and standard numbers(s) in
which they are used (for example, F714).
1.6 Abbreviated Terminology:
1.6.1 Abbreviated terminology is intended to provide uniform contractions of terms relating to plastic piping that have evolved
through widespread common usage. The compilation in this standard has been prepared to avoid the occurrence of more than one
abbreviated term for a given plastics piping term and to avoid multiple meanings for abbreviated terms.
1.6.2 The abbreviated terminology and descriptions in this standard are intended to be consistent with usage in plastics piping and
the standards under F17 jurisdiction. Other ASTM Committees may assign a different word-phrase description to the same
abbreviated terminology. In such cases, the abbreviated terms in this standard shall apply to usage in F17 standards, or if
widespread misunderstanding could result from conflicting abbreviated terminology descriptions, the abbreviated terminology for
the word-phrase shall not be used in F17 standards.
1.6.3 Acronyms and Initialisms—A word formed from the letters or parts of words of a longer word-phrase, usually from the initial
letters or parts of the words. An Acronym is pronounced as a word, for example radar, for radio detection and ranging. An Initialism
is pronounced as a series of letters, for example DOT for Department of Transportation.
1.6.4 The Acronym or Initialism description is the origin word-phrase for the Acronym or Initialism, not a definition.
This terminology is under the jurisdiction of ASTM Committee F17 on Plastic Piping Systems and is the direct responsibility of Subcommittee F17.91 on Editorial and
Terminology.
Current edition approved Dec. 1, 2021July 1, 2023. Published January 2022July 2023. Originally approved in 1975. Last previous edition approved in 20202021 as
F412 – 20a.F412 – 21. DOI: 10.1520/F0412-21.10.1520/F0412-23.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F412 − 23
1.7 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.
2. Referenced Documents
2.1 ASTM Standards:
C114 Test Methods for Chemical Analysis of Hydraulic Cement
D256 Test Methods for Determining the Izod Pendulum Impact Resistance of Plastics
D638 Test Method for Tensile Properties of Plastics
D648 Test Method for Deflection Temperature of Plastics Under Flexural Load in the Edgewise Position
D747 Test Method for Apparent Bending Modulus of Plastics by Means of a Cantilever Beam (Withdrawn 2019)
D790 Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials
D882 Test Method for Tensile Properties of Thin Plastic Sheeting
D883 Terminology Relating to Plastics
D907 Terminology of Adhesives
D1003 Test Method for Haze and Luminous Transmittance of Transparent Plastics
D1079 Terminology Relating to Roofing and Waterproofing
D1238 Test Method for Melt Flow Rates of Thermoplastics by Extrusion Plastometer
D1488 Test Method for Amylaceous Matter in Adhesives
D1505 Test Method for Density of Plastics by the Density-Gradient Technique
D1527 Specification for Acrylonitrile-Butadiene-Styrene (ABS) Plastic Pipe, Schedules 40 and 80 (Withdrawn 2013)
D1600 Terminology for Abbreviated Terms Relating to Plastics
D1785 Specification for Poly(Vinyl Chloride) (PVC) Plastic Pipe, Schedules 40, 80, and 120
D2104 Specification for Polyethylene (PE) Plastic Pipe, Schedule 40 (Withdrawn 2010)
D2239 Specification for Polyethylene (PE) Plastic Pipe (SIDR-PR) Based on Controlled Inside Diameter
D2241 Specification for Poly(Vinyl Chloride) (PVC) Pressure-Rated Pipe (SDR Series)
D2282 Specification for Acrylonitrile-Butadiene-Styrene (ABS) Plastic Pipe (Withdrawn 2006)
D2444 Practice for Determination of the Impact Resistance of Thermoplastic Pipe and Fittings by Means of a Tup (Falling
Weight)
D2447 Specification for Polyethylene (PE) Plastic Pipe, Schedules 40 and 80, Based on Outside Diameter (Withdrawn 2010)
D2513 Specification for Polyethylene (PE) Gas Pressure Pipe, Tubing, and Fittings
D2661 Specification for Acrylonitrile-Butadiene-Styrene (ABS) Schedule 40 Plastic Drain, Waste, and Vent Pipe and Fittings
D2666 Specification for Polybutylene (PB) Plastic Tubing (Withdrawn 2003)
D2680 Specification for Acrylonitrile-Butadiene-Styrene (ABS) and Poly(Vinyl Chloride) (PVC) Composite Sewer Piping
D2683 Specification for Socket-Type Polyethylene Fittings for Outside Diameter-Controlled Polyethylene Pipe and Tubing
D2737 Specification for Polyethylene (PE) Plastic Tubing
D2751 Specification for Acrylonitrile-Butadiene-Styrene (ABS) Sewer Pipe and Fittings (Withdrawn 2014)
D2837 Test Method for Obtaining Hydrostatic Design Basis for Thermoplastic Pipe Materials or Pressure Design Basis for
Thermoplastic Pipe Products
D2846/D2846M Specification for Chlorinated Poly(Vinyl Chloride) (CPVC) Plastic Hot- and Cold-Water Distribution Systems
D3035 Specification for Polyethylene (PE) Plastic Pipe (DR-PR) Based on Controlled Outside Diameter
D3139 Specification for Joints for Plastic Pressure Pipes Using Flexible Elastomeric Seals
D3212 Specification for Joints for Drain and Sewer Plastic Pipes Using Flexible Elastomeric Seals
D3261 Specification for Butt Heat Fusion Polyethylene (PE) Plastic Fittings for Polyethylene (PE) Plastic Pipe and Tubing
D3309 Specification for Polybutylene (PB) Plastic Hot- and Cold-Water Distribution Systems
D3350 Specification for Polyethylene Plastics Pipe and Fittings Materials
F3378/F3378M Specification for Crosslinkable Polyethylene (CX-PE) Pipe
F3507 Practice for Butt-Fusion Joining of Crosslinkable Polyethylene (CX-PE) Pipe and Tubing
F3525/F3525M Specification Fabricated Fittings of Crosslinkable Polyethylene (CX-PE)
F402 Practice for Safe Handling of Solvent Cements, Primers, and Cleaners Used for Joining Thermoplastic Pipe and Fittings
F405 Specification for Corrugated Polyethylene (PE) Pipe and Fittings (Withdrawn 2015)
F441/F441M Specification for Chlorinated Poly(Vinyl Chloride) (CPVC) Plastic Pipe, Schedules 40 and 80
F442/F442M Specification for Chlorinated Poly(Vinyl Chloride) (CPVC) Plastic Pipe (SDR–PR)
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
F412 − 23
F449 Practice for Subsurface Installation of Corrugated Polyethylene Pipe for Agricultural Drainage or Water Table Control
F628 Specification for Acrylonitrile-Butadiene-Styrene (ABS) Schedule 40 Plastic Drain, Waste, and Vent Pipe With a Cellular
Core
F645 Guide for Selection, Design, and Installation of Thermoplastic Water- Pressure Piping Systems
F714 Specification for Polyethylene (PE) Plastic Pipe (DR-PR) Based on Outside Diameter
F771 Specification for Polyethylene (PE) Thermoplastic High-Pressure Irrigation Pipeline Systems (Withdrawn 2013)
F876 Specification for Crosslinked Polyethylene (PEX) Tubing
F877 Specification for Crosslinked Polyethylene (PEX) Hot- and Cold-Water Distribution Systems
F891 Specification for Coextruded Poly(Vinyl Chloride) (PVC) Plastic Pipe With a Cellular Core
F948 Test Method for Time-to-Failure of Plastic Piping Systems and Components Under Constant Internal Pressure With Flow
(Withdrawn 2018)
F1025 Guide for Selection and Use of Full-Encirclement-Type Band Clamps for Reinforcement or Repair of Punctures or Holes
in Polyethylene Gas Pressure Pipe
F1281 Specification for Crosslinked Polyethylene/Aluminum/Crosslinked Polyethylene (PEX-AL-PEX) Pressure Pipe
F1335 Specification for Pressure-Rated Composite Pipe and Fittings for Elevated Temperature Service (Withdrawn 2011)
F1417 Practice for Installation Acceptance of Plastic Non-pressure Sewer Lines Using Low-Pressure Air
F1473 Test Method for Notch Tensile Test to Measure the Resistance to Slow Crack Growth of Polyethylene Pipes and Resins
F1488 Specification for Coextruded Composite Pipe
F1499 Specification for Coextruded Composite Drain, Waste, and Vent Pipe (DWV)
F1545 Specification for Plastic-Lined Ferrous Metal Pipe, Fittings, and Flanges
F1668 Guide for Construction Procedures for Buried Plastic Pipe
F1733 Specification for Butt Heat Fusion Polyamide(PA) Plastic Fitting for Polyamide(PA) Plastic Pipe and Tubing
F1760 Specification for Coextruded Poly(Vinyl Chloride) (PVC) Non-Pressure Plastic Pipe Having Reprocessed-Recycled
Content
F1924 Specification for Plastic Mechanical Fittings for Use on Outside Diameter Controlled Polyethylene Gas Distribution Pipe
and Tubing
F1948 Specification for Metallic Mechanical Fittings for Use on Outside Diameter Controlled Thermoplastic Gas Distribution
Pipe and Tubing
F1970 Specification for Special Engineered Fittings, Appurtenances or Valves for use in Poly (Vinyl Chloride) (PVC) or
Chlorinated Poly (Vinyl Chloride) (CPVC) Systems
F1973 Specification for Factory Assembled Anodeless Risers and Transition Fittings in Polyethylene (PE) and Polyamide 11
(PA11) and Polyamide 12 (PA12) Fuel Gas Distribution Systems
F1986 Specification for Multilayer Pipe Type 2, Compression Fittings, and Compression Joints for Hot and Cold Drinking-Water
Systems (Withdrawn 2020)
F1987 Specification for Multilayer Pipe Type 2, Compression Fittings, and Compression Joints for Hydronic Heating Systems
(Withdrawn 2020)
F2145 Specification for Polyamide 11 (PA 11) and Polyamide 12 (PA12) Mechanical Fittings for Use on Outside Diameter
Controlled Polyamide 11 and Polyamide 12 Pipe and Tubing
F2158 Specification for Residential Central-Vacuum Tube and Fittings
F2160 Specification for Solid Wall High Density Polyethylene (HDPE) Conduit Based on Controlled Outside Diameter (OD)
F2176 Specification for Mechanical Couplings Used on Polyethylene Conduit, Duct and Innerduct
F2206 Specification for Fabricated Fittings of Butt-Fused Polyethylene (PE)
F2389 Specification for Pressure-rated Polypropylene (PP) Piping Systems
F2623 Specification for Polyethylene of Raised Temperature (PE-RT) Systems for Non-Potable Water Applications
F2769 Specification for Polyethylene of Raised Temperature (PE-RT) Plastic Hot and Cold-Water Tubing and Distribution
Systems
F2788/F2788M Specification for Metric and Inch-sized Crosslinked Polyethylene (PEX) Pipe
F2818 Specification for Specification for Crosslinked Polyethylene (PEX) Material Gas Pressure Pipe and Tubing
F2829/F2829M Specification for Metric- and Inch-Sized Fittings for Crosslinked Polyethylene (PEX) Pipe
F2905/F2905M Specification for Crosslinked Polyethylene (PEX) Line Pipe For Oil and Gas Producing Applications
F2929 Specification for Crosslinked Polyethylene (PEX) Tubing of 0.070 in. Wall and Fittings for Radiant Heating Systems up
to 75 psig
F2968/F2968M Specification for Crosslinked Polyethylene (PEX) Pipe for Gas Distribution Applications
2.2 ISO Standards:
ISO 3 Preferred Numbers
ISO 497 Preferred Numbers
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
F412 − 23
ISO 12162 Thermoplastic materials for pipes and fittings for pressure applications – Classification, designation and design
coefficient
ISO R 161 Pipes of Plastics Materials for the Transport of Fluids (Outside Diameters and Nominal Pressures) Part I, Metric
Series
ISO 9080 Thermolplastics Pipes for the Transport of Fluids-Methods of Extrapolation of Hydrostatic Stress Rupture Data to
Determine the Long-Term Hydrostatic Strength of Thermoplastic Pipe Materials
2.3 ANSI Standard:
Z17.1 ANSI Preferred Numbers
2.4 PPI Standard:
PPI TR-4
3. Terminology
acceptance testing—testing performed on a product to determine whether or not an individual lot of the product conforms with
specified requirements. [F17]
DISCUSSION—
The number of requirements are usually fewer than for qualification testing (see definition).
acetal plastics, n—highly crystalline linear thermoplastic homopolymers or copolymers characterized by repeating oxymeth-
ylene units. [F17]
acrylonitrile-butadiene-styrene (ABS) pipe and fitting plastics —plastics containing polymers or blends of polymers, or both,
in which the minimum butadiene content is 6%, the minimum acrylonitrile content is 15 %, the minimum styrene or substituted
styrene content, or both, is 15 %, and the maximum content of all other monomers is not more than 5 %; plus lubricants,
stabilizers, and colorants. [F17.61] D1527, D2282 [17.62] D2680, D2751
adhesive—a substance capable of holding materials together by surface attachment. [F17]
adhesive bonded joint—see joint, adhesive bonded.
adhesive, solvent—see solvent cement.
adiabatic extrusion—a method of extrusion in which, after the extrusion apparatus has been heated sufficiently by conventional
means to plastify the material, the extrusion process can be continued with the sole source of heat being the conversion of the
drive energy, through viscous resistance of the plastic mass in the extruder. [D20] D883
aging, n—
(1) the effect on materials of exposure to an environment for an interval of time.
(2) the process of exposing materials to an environment for an interval of time. [D20] D883
alloy, n—in plastics, two or more immiscible polymers united, usually by another component, to form a plastic resin having
enhanced performance properties. [D20] D883
allowable stress—The maximum force per unit area that may be safely applied to a pipe.
DISCUSSION—
In Guide F645, the allowable stress is determined by multiplying the hydrostatic design stress (HDS) at 73°F by the temperature correction factor.
[F17.61] F645
antioxidant, n—compounding ingredient used to retard deterioration caused by oxidation. [F17]
apparent density—the weight per unit volume of a material including voids inherent in the material as tested. [F17]
Available from Plastics Pipe Institute (PPI), 105 Decker Court, Suite 825, Irving, TX 75062, http://www.plasticpipe.org.
F412 − 23
DISCUSSION—
The term bulk density is commonly used for material such as molding powder.
approving authority—the individual official, board, department, or agency established and authorized by a state, county, city,
or other political subdivision, created by law to administer and enforce specified requirements.
artificial weathering—exposure to laboratory conditions, which may be cyclic, involving temperature, relative humidity,
radiant energy, or any other conditions or pollutants found in the atmosphere in various geographical areas; or both. [F17]
DISCUSSION—
The interlaboratory exposure conditions are usually intensified beyond those encountered in actual outdoor exposure in an attempt to achieve an
accelerated effect.
backfill—all material used to fill the trench from bedding to finished surface. [F17.65 ] F449, F1668
backfill, final—material used to fill the trench from initial backfill to finished surface. [F17]
backfill, initial—material used to fill the trench from top of bedding to a designated height over the pipe. [F17]
backfill, pipe zone—see pipe zone backfill.
backfill, unconsolidated—noncompacted material in place in trench. [F17]
bead-up cycle, n—part of the fusion procedure that insures complete contact between the heater surfaces and the pipe ends by
applying pressure such as fusion joining pressure to force the pipe ends against the heater surfaces.
DISCUSSION—
The bead-up cycle begins at initial contact of the pipe ends against the heater and ends when an indication of melt (slight melt bead) is observed around
the pipe circumference.
beam loading—the application of a load to a pipe between two points of support, usually expressed in newtons (or
pounds-force) and the distance between the centers of the supports. [F17]
bedding, n—materials placed in the bottom of the trench on top of the foundation soil which provides stable bottom support for
buried pipe including the trench bottom groove support angle or select material placed around the pipe, and envelope or filter
materials where used during insulation. [F17.65] F449, F1668
bedding, v—placement of support materials for buried pipe. [F17]
bell-and-spigot joint—see joint, bell-and-spigot gasket.
bell end—the enlarged portion of a pipe that resembles the socket portion of a fitting and that is intended to be used to make
a joint. [F17]
bend—a fitting either molded separately or formed from pipe for the purpose of accommodating a directional change. [F17]
DISCUSSION—
Also called ell,elbow, or sweep. Bends generally imply fittings of relatively shorter radii than sweeps.
beveled pipe—a pipe with an end chamfered to mate or adjust to another surface or to assist in assembly. [F17]
binder, n—in a reinforced plastic, the continuous phase which holds together the reinforcement. [D20] D883
DISCUSSION—
During fabrication, the binder, which may be either thermoplastic or thermoset, usually undergoes a change in state.
F412 − 23
blinding—the placement of soil, bedding material over and on the sides of the pipe, tubing or envelope to ensure proper grade,
alignment, support, and protection of pipe during backfilling and after installation. [F17.65] F449
blister, n—an imperfection, a rounded elevation of the surface of a plastic, with boundaries that may be more or less sharply
defined, somewhat resembling in shape a blister on the human skin. [D20] D883
bloom, n—a visible exudation or efflorescence on the surface of a material. [D20] D883
blow molding—a method of fabrication in which a heated parison (hollow tube) is forced into the shape of a mold cavity by
internal gas pressure. [D20] D883
blowing agent—a compounding ingredient used to produce gas by chemical or thermal action, or both, in manufacture of
hollow or cellular articles. [D20] D883
brittle failure—a pipe failure mode which exhibits no visible (to the naked eye) permanent material deformation (stretching,
elongation, or necking down) in the area of the break. [F17.40] F1473
building drain—that part of the lowest horizontal piping of a drainage system that receives the discharge from soil, waste, and
other drainage pipes inside the walls of the building and conveys it to the building sewer beyond the foundation walls of the
building or structure. [F17]
DISCUSSION—
The building sewer generally begins 2 to 5 ft beyond the foundation walls.
building drain (sanitary)—a building drain that conveys gray water or sewage, or both. [F17]
building drain (storm)—a building drain that conveys storm water only. [F17]
building sanitary sewer—that part of the horizontal piping of a sanitary drainage system which extends from the building
sanitary drain, receives the discharge of the building sanitary drain, and conveys it to a public sewer, private sewer, individual
sewage disposal system, or other point of disposal. [F17]
building storm sewer—that part of the horizontal piping of a storm drainage system which extends from the building storm
drain, receives the discharge of the building storm drain, and conveys it to a public storm sewer, private storm sewer, or other
point of disposal. [F17]
building supply—See water service.
bulk factor, n—the ratio of the volume of a given mass of molding material to its volume in the molded form. ISO/[D20] D883
DISCUSSION—
The bulk factor is also equal to the ratio of the density of the material to its apparent density in the unmolded form.
burst strength—the internal pressure required to cause a pipe or fitting to fail. [F17]
DISCUSSION—
This pressure will vary with the rate of buildup of the pressure and the time during which the pressure is held.
butt-fused joint—see joint, butt-fused.
butylene plastics—plastics based on resins made by the polymerization of butene or copolymerization of butene with one or
more unsaturated compounds, the butene being in greatest amount by weight. [D20] D883
F412 − 23
categorized required strength , CRS , n—one of a series of classifications for the 97.5 % lower confidence limit, σ , of
θ,t θ,t LPL
the predicted long-term hydrostatic strength of a plastic compound determined in accordance with ISO 9080 and ISO 12162,
expressed in MPa at a temperature, θ, in °C other than 20 °C and a time, t, in years. [F17]
cell, n—a small cavity surrounded partially or completely by walls. [D20] D883
cell, closed—a cell totally enclosed by its walls and hence not interconnecting with other cells. (See also cell and cell, open.)
ISO/[D20] D883
cell, open—a cell not totally enclosed by its walls and hence interconnecting with other cells. (See also cell and cell, closed.)
[D20] D883
cellular plastic—a plastic containing numerous cells, intentionally introduced, interconnecting or not, distributed throughout the
mass. [D20] D883 [17.63] F628 [17.25] F891
cellulose acetate butyrate (CAB) plastics—plastic made by compounding a cellulose acetate butyrate ester with plasticizers
and other ingredients. Cellulose acetate butyrate ester is a derivative of cellulose (obtained from cotton or wool pulp, or both)
made by converting some of the hydroxyl groups in cellulose to acetate and butyrate groups with chemicals. [F17]
central vacuum tubing, n—plastic tubing used for residental central vacuum systems in which outside diameter is controlled
and where the wall thickness is usually small when compared to the diameter. [F17.25] F2158
chalking, n—in plastics, a powdery residue on the surface of a material resulting from degradation or migration of an ingredient,
or both. [D20] D883
DISCUSSION—
Chalking may be a designed-in characteristic.
chamfered pipe—a pipe with a conical surface (angle) made by cutting off the edge around the outside diameter on the end of
a pipe.
DISCUSSION—
To assist in assembly, of socket joining, (solvent cementing, gasketed, and socket fusion) burrs on the pipe OD are removed by chamfering. Refer to
product manufacturer’s recommendations. [F17]
FIG. 1 Chamfered Pipe
chemical cleaner—see cleaner, chemical.
chemical resistance—the ability to resist chemical attack. [F17]
DISCUSSION—
The attack is dependent on the method of test and its severity is measured by determining the changes in physical properties. Time, temperature, stress,
and reagent may all be factors that affect the chemical resistance of a material.
F412 − 23
chemically formed polymeric material—a cellular material in which the cells are formed by gases generated from thermal
decomposition or other chemical reaction. [D20] D883
chlorinated poly(vinyl chloride) plastics—plastics based on chlorinated poly(vinyl chloride) in which the chlorinated
poly(vinyl chloride) is in the greatest amount by weight. [D20] D883
chlorofluorocarbon plastics—plastics based on polymers made with monomers composed of chlorine, fluorine, and carbon
only. ISO/ [D20] D883
chlorofluorohydrocarbon plastics, n—plastics based on polymers made with monomers composed of chlorine, fluorine,
hydrogen, and carbon only. ISO/[D20] D883
cleaner, chemical—an organic solvent used to remove foreign matter from the surface of plastic pipe and fittings. [F17.20] F402
DISCUSSION—
Cleaners have essentially no effect on the plastic surface being cleaned and may be used prior to joining with a solvent cement or adhesive.
cleaner, mechanical—an abrasive material or device used to remove foreign matter and gloss from the surface of plastic pipe
and fittings. [F17]
DISCUSSION—
Mechanical cleaners may be used prior to joining with a solvent cement or adhesive.
closed-cell cellular plastics—cellular plastics in which almost all the cells are noninterconnecting. [D20] D883 [F17.63] F628
closed-cell foamed plastics—See closed-cell cellular plastics.
code—(1) a system of symbols, letters or numbers, used to convey a message requiring brevity; (2) a set of rules established
by a legal or quasi-legal body. [F17]
code, classification—a code that identifies a plastic material by its properties in accordance with the pertinent ASTM
specification. [F17]
code, manufacturer’s—a code that provides manufacturing identity for a piping product. [F17]
code, thermoplastic pipe material designation— letters and ciphers for the designation of stress-rated thermoplastic
compound, which consists of two or more characters to indicate the abbreviation as listed in Terminology D1600, for the type
of thermoplastic resin—followed by four or five Arabic numerals—two or three to describe the short-term properties, in
accordance with the ASTM standard being referenced, and two to designate the hydrostatic design stress when tested in water
at 73°F (23°C) in units of 100 psi, with any decimal figures dropped. [F17]
DISCUSSION—
In some ASTM standards, the short-term properties with more than two numbers have a table provided to convert to two numbers to be used in the
code.
DISCUSSION—
When the hydrostatic design stress code is less than two numbers, a zero is inserted before the number.
DISCUSSION—
For polyethylene compound, the short-term properties are described using two Arabic numerals in accordance with Specification D3350, specifically,
the cell classification number value for density followed by the cell classification number value for slow crack growth resistance.
DISCUSSION—
For crosslinked polyethylene (PEX) materials, the short-term properties are described using two Arabic numerals in accordance with Specification
F876, specifically, a digit for chlorine resistance performance followed by a digit for UV resistance performance.
F412 − 23
coextrusion—a process whereby two or more heated or unheated plastic material streams forced through one or more shaping
orifice(s) become one continuously formed piece. [F17.63] D2661, F628 [F17.25] F891, F1760 [F17.11] F1488
cold flow—See creep.
cold molding—a special process of compression molding in which the molding is formed at room temperature and subsequently
baked at elevated temperatures. [D20] D883
collapse, n—(1) inadvertent densification of cellular material during manufacture resulting from breakdown of cell structure; (2)
the buckling of the inner liner of composite piping; (3 ) the buckling or flattening of a plastic rehabilitation liner; (4) the buckling
or crushing of a plastic pipe from external forces, such as earth loads or external hydrostatic load. [F17]
compaction, soil—act of packing soil with mechanical force to increase its density. [F17]
compatible—(1) a condition wherein components of a plastic piping system or different specific plastic materials, or both, can
be joined together for satisfactory joints. (2) in relation to elastomeric seal joints, a condition wherein the elastomer does not
adversely affect the pertinent properties of the plastic pipe or fittings, or both, when the sealing gasket is in intimate contact with
the plastic for a prolonged period. [F17]
composite pipe—pipe consisting of two or more different materials arranged with specific functional purpose to serve as pipe.
[F17]
compound, n—a mixture of a polymer with other ingredients such as fillers, stabilizers, catalysts, processing aids, lubricants,
modifiers, pigments, or curing agents. [F17.11] F1488, F1499
compression fitting joint—see joint, compression fitting.
compression gasket joint—see joint, compression gasket.
compression molding—the method of molding a material already in a confined cavity by applying pressure and usually heat.
[D20] D883
conduit, (duct), n—a tubular raceway for carrying electric wires, cables, or other conductors. [F17.10] F2176 [F17.26] F2160
consolidation—reduction in volume of soil as a result of gravitational forces. [F17]
contamination—the presence of a substance not intentionally incorporated in a product. [F17]
continuous waste—a drain connecting two or more plumbing fixtures or components of plumbing fixtures to a common trap.
[F17]
cool time at fusion pressure, (minimum), n—the minimum duration that fusion pressure is maintained while the joined pipe
faces drop in temperature and solidify.
coupon, n—a piece or portion of a sample used to make a specimen.
crack—any narrow opening or fissure in the surface that is visible to the naked eye. [F17.65] F405
F412 − 23
crater, n—a small, shallow surface imperfection. [D20] D883
crazing, n—apparent fine cracks at or under the surface of a plastic. [D20] D883
DISCUSSION—
The crazed areas are composed of polymeric material of lower density than the surrounding matrix.
creep, n—the time-dependent part of strain resulting from stress, that is dimensional change caused by the application of load
over and above the elastic deformation and with respect to time. [D20] D883, [17.60] F1025
cross laminate—a laminate in which some of the layers of material are oriented approximately at right angles to the remaining
layers with respect to the grain or strongest direction in tension. (See also parallel laminate.) [D20] D883
crosslinkable polyethylene (CX-PE), n—a polyethylene compound that has been chemically modified such that exposure to
defined conditions of time, temperature, moisture, and pressure, which are intended to be fulfilled after installation will result
in the material meeting the physical requirements of crosslinked polyethylene (PEX). [F17] F3378/F3378M, F3507,
F3525/F3525M
crosslinked polyethylene (PEX), n—a polyethylene material that has undergone a change in molecular structure through
processing whereby a majority of the polymer chains are chemically linked. [F17] F876, F1281, F2788/F2788M, F2818,
F2829/F2829M, F2905/F2905M, F2929, F2968/F2968M
crosslinking, n—the formation of a three dimensional polymer by means of interchain reactions resulting in changes in physical
properties. [D20] D883
cure, v—to change the properties of a polymeric system into a more stable, usable condition by the use of heat, radiation, or
reaction with chemical additives. ISO/[D20] D883
DISCUSSION—
Cure may be accomplished, for example, by removal of solvent or by crosslinking.
deadload—the static load imposed on the top of the pipe. [F17]
deburred pipe—a pipe with the sharp edge and/or cutting remnants removed from the pipe end ID or OD edges.
DISCUSSION—
Pipe cutting can result in burrs and shavings at the pipe ID and OD edges. Sharp edges and cutting remnants can interfere with flow or joining. For
socket joining, (solvent cementing, gasketed and socket fusion) burrs on the pipe OD are removed by chamfering. Refer to product manufacturers
recommendations. [F17]
FIG. 2 Deburred Pipe
deflection temperature—the temperature at which a specimen will deflect a given distance at a given load under prescribed
conditions of test. (See Test Method D648.) Formerly called heat distortion. [F17]
F412 − 23
degradation, n—a deleterious change in chemical structure, physical properties, or appearance of a plastic. [D20] D883
density, apparent—see apparent density.
3 3
density of plastics—the weight per unit volume of material at 23°C expressed as D23c, g/cm (kg/m ). [F17]
DISCUSSION—
Taken from Test Method D1505.
depth, n—in the case of a beam, the dimension parallel to the direction in which the load is applied. [D20] D883
diffusion—the movement of a material such as a gas or liquid, in the body of a plastic. [F17]
DISCUSSION—
If the gas or liquid is absorbed on one side of a piece of plastic and given off on the other side, the phenomenon is called permeability. Diffusion and
permeability are not due to holes or pores in the plastic.
dimension ratio (DR)—the average specified diameter of a pipe or tubing divided by the minimum specified wall thickness.
The DR values shall be rounded to the nearest 0.5 unless otherwise specified. [F17.10] D2683, D3261, F1733 [17.11] D1488
[F17.26] D2737, [F17.60] D2513
DISCUSSION—
Each pipe can have two dimension ratios depending on whether the outside or inside diameter is used. In practice, the outside diameter is used if the
standards requirement and manufacturing control are based on this diameter. The inside diameter is used when this measurement is the controlling one.
drag pressure (psi), n—the fusion machine’s hydraulic pressure required to overcome the static and dynamic resistance to
motion of the movable carriage.
dry-blend, n—dry compound prepared without fluxing or addition of solvent (also called powder blend). [D20] D883
ductile failure—a pipe failure mode which exhibits material deformation (stretching, elongation, or necking down) in the area
of the break. [F17]
elastomer, n—a macromolecular material that at room temperature returns rapidly to approximately its initial dimensions and
shape after substantial deformation by a weak stress and release of the stress. [D20] D883
elastomeric seal—a material or device that uses an elastomer to effect a seal between separable piping components. [F17]
elevated temperature testing—tests on plastic pipe above 23°C (73°F). [F17]
embedment—the placement of materials completely around the pipe to provide support. [F17.62] F1668
encasement, n—see incasement,n.
encasement, v—see incasement, v.
engineering plastics, n—those plastics and polymeric compositions for which well-defined properties are available, such that
engineering rather than empirical methods can be used for design and manufacture of products requiring definite and predictable
performance in structural applications over a substantial temperature range. [D20] D883
envelope, drainage—the materials completely surrounding a pipe to provide support or protection or act as a filter. [F17]
F412 − 23
environmental stress cracking—the development of cracks in a material that is subjected to stress or strain in the presence of
specific chemicals. [F17]
ethylene plastics, n—plastics based on polymers of ethylene or copolymers of ethylene with other monomers, the ethylene being
in greatest amount by mass. ISO/[D20] D883
exfiltration, pipe—the passage of fluid from a pipe section through small holes or leaks. [F17]
expandable plastic, n—a plastic in a form capable of being made cellular by thermal, chemical, or mechanical means. [D20]
D883
expanded plastics—See cellular plastics.
extrusion, n—a process in which heated or unheated plastic is forced through a shaping orifice (a die) in one continuously
formed shape as film, sheet, rod, or tubing. [D20] D883
extrusion, adiabatic—see adiabatic extrusion.
fabricating, n—the manufacture of plastic products from molded parts, rods, tubes, sheeting, extrusions, or other forms by
appropriate operations such as punching, cutting, drilling, and tapping including fastening plastic parts together or to other parts
by mechanical devices, adhesives, heat sealing, or other means. [D20] D883
failure, adhesive—rupture of an adhesive bond, such that the plane of separation appears to be at the adhesive-adherend
interface. [F17]
failure, brittle—see brittle failure
failure, ductile—see ductile failure
failure, slit —see silt failure
filler, n—a relatively inert material added to a plastic to modify its strength, permanence, working properties, or other qualities
or to lower costs. (See also reinforced plastic.) [D20] D883
fish-eye, n—small globular mass that has not blended completely into the surrounding material. [D20] D883
fitting, n—a piping component used to join or terminate sections of pipe or to provide changes of direction or branching in a
pipe system. [F17]
flanged joint—see joint, flanged.
flare joint—see joint, flare.
flow rate—rate of extrusion, weight per unit of time, g/10 min (kg/s), of molten resins through a die of specified length and
diameter, under prescribed conditions of temperature, load, and piston position in the barrel as the timed measurement is being
made. [F17]
fluorocarbon plastic, n—a plastic based on polymers made with perfluoromonomers. ISO/[D20] D883
F412 − 23
DISCUSSION—
When the monomer is essentially tetrafluoroethylene, the prefix TFE is sometimes used to designate these materials. It is preferable to use the accepted
abbreviation, PFTE. TFE should not be used by itself to mean PTFE. When the resins are copolymers of tetrafluoroethylene and hexafluoropropylene,
the resins may be designated with the prefix FEP. Other prefixes may be adopted to designate other fluorocarbon plastics.
fluorohydrocarbon plastics, n—plastics based on polymers made with monomers composed of fluorine, hydrogen, and carbon
only. ISO/[D20] D883
fluoroplastic, n—a plastic based on polymers made from monomers containing one or more atoms of fluorine, or copolymers
of such monomers with other monomers, the fluorine-containing monomer(s) being in the greatest amount by mass. [D20] D883
DISCUSSION—
For specific examples of fluoroplastic see fluorocarbon plastic, chlorofluorocarbon plastics, fluorohydrocarbon plastics, and chlorofluorohy-
drocarbon plastic.
foamed plastics,n—See cellular plastics (the preferred terminology).
forming, n—a process in which the shape of plastic pieces such as sheets, rods, or tubes is changed to a desired configuration.
[D20] D883
DISCUSSION—
The use of the term “forming” in plastics technology does not include such operations as molding, casting, or extrusion, in which shapes or pieces
are made from molding materials or liquids.
frosting, n—a light-scattering surface resembling fine crystals. See also chalking, haze, bloom. [F17]
fungi resistance—the ability of plastic pipe to withstand fungi growth or their metabolic products, or both, under normal
conditions of service or laboratory tests simulating such conditions. [F17]
fuse, v—(1) to convert plastic powder or pellets into a homogeneous mass through heat and pressure; (2) to make a plastic piping
joint by heat and pressure. [F17]
fusion cycle, n—the pressure / time sequence, at a defined heater surface temperature for the fusion procedure, beginning with
the bead-up cycle and ending when the cooling time is complete.
fusion machine operator, n—a trained person qualified to perform fusion joining of plastic pipes and/or fittings based on a
fusion procedure.
fusion pressure (psi), n—for machines with hydraulic pressure capability, this is a calculated number determined by adding the
theoretical fusion pressure (psi) and the drag pressure (psi).
DISCUSSION—
This is the gauge pressure used by the butt fusing operator on the butt fusing machine to join the pipe ends.
fusion procedure, n—a written document that provides detailed steps for performing fusion joining that has been qualified by
testing.
gasket joint—see joint, compression gasket and joint, bell-and-spigot gasket.
gate, n—in an injection mold, a constriction in the flow channel between the runner and the mold cavity. [D20] D883
gel, n—(1) a semisolid system consisting of a network of solid aggregates in which liquid is held; (2) the initial jelly-like solid
phase that develops during the formation of a resin from a liquid; (3) with respect to vinyl plastisols, gel is a state between liquid
and solid that occurs in the initial stages of heating, or upon prolonged storage. [D20] D883
F412 − 23
DISCUSSION—
All three types of gel have very low strengths and do not flow like a liquid. They are soft, flexible, and may rupture under their own weight unless
supported externally.
gel point—the stage at which a liquid begins to exhibit pseudo-elastic properties. [D20] D883
DISCUSSION—
This stage may be conveniently observed from the inflection point on a viscosity-time plot. (See gel (2).)
gel time, n—the period of time from the initial mixing of the reactants of a liquid material composition to the time when gelation
occurs, as defined by a specific test method. [D20] D883
DISCUSSION—
For a material that must be processed by exposure to some form of energy, the zero time is the start of exposure.
glass transition—the reversible change in an amorphous polymer or in amorphous regions of a partially crystalline polymer
from (or to) a viscous or rubbery condition to (or from) a hard and relatively brittle one. [D20] D883
DISCUSSION—
The glass transition generally occurs over a relatively narrow temperature region and is similar to the solidification of a liquid to a glassy state; it is
not a phase transition. Not only do hardness and brittleness undergo rapid changes in this temperature region but other properties, such as thermal
expansibility and specific heat also change rapidly. This phenomenon has been called second order transition, rubber transition, and rubbery transition.
The word transformation has also been used instead of transition. Where more than one amorphous transition occurs in a polymer, the one associated
with segmental motions of the polymer backbone chain or accompanied by the largest change in properties is usually considered to be the glass
transition.
glass transition temperature (Tg)—the approximate midpoint of the temperature range over which the glass transition takes
place. [D20] D883
DISCUSSION—
The glass transition temperature can be determined readily only by observing the temperature at which a significant change takes place in a specific
electrical, mechanical, or other physical property. Moreover, the observed temperature can vary significantly depending on the specific property chosen
for observation and on details of the experimental technique (for example, rate of heating, frequency). Therefore, the observed Tg should be considered
only an estimate. The most reliable estimates are normally obtained from the loss peak observed in dynamic mechanical tests or from dialatometric
data.
graft copolymer—a copolymer in which polymeric side chains have been attached to the main chain of a polymer of different
structure. [D20] D883
gravity flow, n—liquefied medium conveyance that is induced by a positive elevation head such as a downward pipeline slope
or a higher elevation reservoir. [F17]
gravity flow, non-pressure, n—gravity flow of liquefied medium in a piping system that is not pressure-rated and where flow
is regularly less than full (open channel flow) except during conditions when the system may become temporarily surcharged
in which case, the system is subject to temporary internal hydrostatic pressure that is generally limited to piping system joint
capabilities.[F17]
gravity flow, pressure, n—gravity flow of liquefied medium in a pressure-rated piping system where flow regularly fills the
piping system (closed channel flow) and subjects the piping system to internal hydrostatic pressure that
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