15S e2 fm Spoolable Reinforced Plastic Line Pipe API SPECIFICATION 15S SECOND EDITION, MARCH 2016 API MONOGRAM PROGRAM EFFECTIVE DATE SEPTEMBER 1, 2016 ERRATA, JULY 2016 Special Notes API publications[.]
Coverage
This specification outlines the essential requirements for the production and qualification of spoolable reinforced plastic line pipe used in oilfield and energy sectors It encompasses the transportation of multiphase fluids, hydrocarbon gases, hydrocarbon liquids, oilfield production chemicals, and nonpotable water Additionally, it details the performance standards for materials, pipes, and fittings.
These products feature a liner reinforced with helically wrapped steel or nonmetallic elements, along with an outer cover The helical reinforcements must consist of a single material, although additional nonhelical reinforcements are permitted The spoolable reinforced line pipe described here is designed for efficient spooling, storage, transport, and installation Please note that for offshore applications, additional requirements may be applicable, which are not covered in this document.
This specification focuses exclusively on pipes, end-fittings, and couplings, excluding other system components and appurtenances Components such as elbows, tees, and valves, which are of conventional construction, will adhere to relevant codes and practices.
Application of the API Monogram
If the product is manufactured at a facility licensed by API and it is intended to be supplied bearing the API Monogram, the requirements of Annex A apply.
The referenced documents are essential for applying this document For dated references, only the specified edition is applicable, while for undated references, the most recent edition, including any addenda or errata, is relevant This includes API Recommended Practice 17B, which provides guidance on flexible pipe.
API Specification Q1, Specification for Quality Management System Requirements for Manufacturing Organizations for the Petroleum and Natural Gas Industry
API Specification 15LE, Specification for Polyethylene Line Pipe (PE), 4th Edition
API Specification 17J, Specification for Unbonded Flexible Pipe, 4th Edition
API 1104, Standard for Welding Pipelines and Related Facilities
ASME BPVC Section IX, Welding and Brazing Qualifications
ASTM 2 A370, Standard Test Method and Definitions for Mechanical Testing of Steel Products
ASTM A751, Standard Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
ASTM D256, Standard Test Methods for Determining the Izod Pendulum Impact Resistance of Plastics
1 American Society of Mechanical Engineers, Two Park Avenue, New York, New York, 10016-5990, www.asme.org
2 American Society for Testing and Materials International, 100 Barr Harbor Drive, West Conshohocken, Pennsylvania 19428-
ASTM D638, Standard Test Method for Tensile Properties of Plastics
ASTM D695, Standard Test Method for Compressive Properties of Rigid Plastics
ASTM D746, Standard Test Method for Brittleness Temperature of Plastics and Elastomers by Impact
ASTM D792, Standard Test Method for Density and Specific Gravity (Relative Density) of Plastics by Displacement
ASTM D885, Standard Test Methods for Tire Cords, Tire Cord Fabrics, and Industrial Filament Yarns Made from
ASTM D1505, Standard Test Method for Density of Plastics by the Density-Gradient Technique
ASTM D1598, Test Method for Time-To-Failure of Plastic Pipe under Constant Internal Pressure
The ASTM D1599 test method evaluates the resistance of plastic pipes, tubing, and fittings to short-time hydraulic pressure, ensuring their durability and safety in various applications Meanwhile, ASTM D2256 provides a standard procedure for assessing the tensile properties of yarns using the single strand method, which is crucial for determining the strength and performance of textile materials.
ASTM D2412, Test Method for Determination of External Loading Characteristics of Plastic Pipe by Parallel-Plate
ASTM D2444, Standard Test Method for Determination of the Impact Resistance of Thermoplastic Pipe and Fittings by Means of a Tup (Falling Weight)
ASTM D2513-14, Standard Specification for Polyethylene (PE) Gas Pressure Pipe, Tubing, and Fittings
ASTM D2565, Standard Practice for Xenon-Arc Exposure of Plastics Intended for Outdoor Applications
ASTM D2990, Standard Test Methods for Tensile, Compressive, and Flexural Creep and Creep-Rupture of Plastics
ASTM D2992-12, Practice for Obtaining Hydrostatic or Pressure Design Basis for "Fiberglass" (Glass-Fiber-
Reinforced Thermosetting Resin) Pipe and Fittings
ASTM D3222, Standard Specification for Unmodified Poly (Vinylidene Fluoride) (PVDF) Molding Extrusion and
ASTM D3350, Standard Specification for Polyethylene Pipe and Fittings Materials
ASTM D3418-12e1, Standard Test Method for In-Plane Shear Response of Polymer Matrix Composite Materials by
ASTM D4000, Standard Classification System for Specifying Plastic Materials
ASTM D4067, Standard Classification System for and Basis for Specification for Reinforced and Filled Poly
(Phenylene Sulfide) (PPS) Injection Molding and Extrusion Materials Using ASTM Methods
ASTM D4101, Standard Specification for Polypropylene Injection and Extrusion Materials
ASTM D5575, Standard Classification System for Copolymers of Vinylidene Fluoride (VDF) with Other Fluorinated
ASTM D5857, Standard Specification for Polypropylene Injection and Extrusion Materials Using ISO Protocol and
ASTM D6358, Standard Classification System and Basis for Specification for Poly (Phenylene Sulfide) (PPS)
Injection Molding and Extrusion Materials Using ISO Methods
ASTM D6779, Standard Classification system for and Basis of Specification for Polyamide Molding and Extrusion
ASTM D7269, Standard Test Methods for Tensile Testing of Aramid Yarns
ASTM E328, Standard Test Methods for Stress Relaxation Tests for Materials and Structures
ASTM E739, Standard Practice for Statistical Analysis of Linear or Linearized Stress-Life (S-N) and Strain-Life (?-N)
ASTM E1356, Standard Test Method for Assignment of the Glass Transition Temperatures by Differential Scanning
ASTM F876, Standard Specification for Crosslinked Polyethylene (PEX) Tubing
ASTM F2619-13, Standard Specification for High-Density Polyethylene (PE) Line Pipe
ISO 3 4437-1:2014, Plastics piping systems for the supply of gaseous fuels
ISO 9001, Quality Management Systems—Requirements
ISO 11357, Differential scanning calorimetry (DSC)
ISO 15156, Petroleum and natural gas industries-Materials for use in H2S-containing environments in oil and gas production
ISO 17025, General requirements for the competence of testing and calibration laboratories
ISO/IEC 17020, Conformity assessment—Requirements for the operation of various types of bodies performing inspection
ISO/IEC 17065, Conformity assessment—Requirements for bodies certifying products, processes and services
ISO/TS 29001, Petroleum, Petrochemical and Natural Gas Industries—Sector-Specific Quality Management
Systems - Requirements for Product and Service Supply Organizations
NACE 4 MR0175, Petroleum and natural gas industries-Materials for use in H2S-containing environments in oil and gas production
NACE TM0177, Laboratory Testing of Metals for Resistance to Sulfide Stress Cracking and Stress Corrosion
PPI 5 TR-3, Policies and Procedures for Developing Hydrostatic Design Basis (HDB), Pressure Design Basis (PDB),
Strength Design Basis (SDB), and Minimum Required Strength (MRS) Ratings for Thermoplastic Piping Materials or Pipe
ISO publications can be obtained from the American National Standards Institute (ANSI) located at 25 West 43rd Street, 4th Floor, New York, NY 10036 For more information, visit their websites at www.iso.org and www.ansi.org.
4 National Association of Corrosion Engineers International, 1440 South Creek Drive, P.O Box 218340, Houston, Texas 77218-
5 Plastics Pipe Institute, 105 Decker Court, Suite 825, Irving, TX 75062, www.plasticpipe.org
For the purposes of this document, the following terms, definitions, and abbreviations apply.
Terms and Definitions
Pipe produced sequentially with no interruptions or shutdowns that are not a part of the normal production process.
Damage in the form of gas-filled pockets caused by the release of absorbed gas on depressurization within a solid polymer layer (e.g polymeric liner).
Device used to provide a leak-tight structural connection between the end-fitting and adjacent piping (e.g bolted flanges, clamped hubs, and proprietary connectors).
Specific type of fitting developed for joining one section of pipe to another.
Protective outer sheath of the pipe.
Failure as a result of a period under steady stress or pressure (also known as static fatigue).
More than 7000 cycles and ΔP/NPR > 6 % where ΔP is maximum to minimum amplitude.
Extraction or loss of any of a group of additive substances in a polymer formulation that are used to impart flexibility or other properties to the finished product.
A period of time used in design calculations, selected for the purpose of verifying that a replaceable or permanent component is suitable for the anticipated period of service.
NOTE A properly maintained and protected pipeline system may be able to provide longer service with proper justification
Separation of the bonded layers.
A mechanical device that forms the transition from the pipe to the connector.
A value of one or less accounts for manufacturing and testing variables, including normal material variations, manufacturing processes, dimensions, handling and installation techniques, as well as the precision and bias of testing methods.
A set of operational factors, each valued at one or less, takes into account the application or usage, including environmental conditions such as fluids, cyclic loading, and temperature, as outlined in this document.
End-fitting or coupling designed for permanent installation.
Action(s) that an item is designed to perform.
Used for testing to determine the properties of the pipe body.
Continuous polymeric layer that is in contact with the conveyed fluid.
Movement of the liner away from the structural layer on reduction of internal pressure.
Hydrostatic pressure calculated for a specific time-to-failure using Formula A1.25 in ASTM D2992-12, replacing σy by σn in accordance with A1.4.6.4 in ASTM D2992-12.
NOTE For 95 % confidence limits, there is a 2.5 % probability that the pipe's actual mean pressure versus time-to-failure regression line may fall below this calculated LCL.
Hydrostatic pressure calculated for a specific time-to-failure using Formula A1.25 in ASTM D2992-12
NOTE For 95 % prediction limits, there is a 2.5 % probability that an individual data point may fall below this calculated LPL.
Lowest allowable pipe temperature for deployment, e.g unspooling
Entity that fabricates products according to this specification (and applies the monogram if a licensee).
The estimated maximum internal hydrostatic pressure that can be applied continuously to a pipe with a high degree of certainty that failure of the component will not occur.
Pressure obtained by multiplying the NPR by application related service factors.
Minimum allowable bend radius for the installed and pressurized pipe.
Minimum allowable bend radius when respooling the pipe in the factory or the field.
Minimum allowable bend radius the unpressurized pipe is subjected to during any handling.
Pressure rating of the pipe as defined by the manufacturer and does not exceed the MPR.
Group of pipe products being a range of sizes and pressure ratings manufactured with the same material types, production process and process controls, and pipe construction.
Product variant chosen for full qualification.
Member of a product family with a specific pressure rating and diameter.
A person, organization, or other entity that is a recipient of a pipeline product provided by a seller under a purchase order or contract of sale.
An individual who has been evaluated and can perform assigned covered tasks and recognize and react to abnormal operating conditions.
Procedure subjected to sufficient testing to show that the procedure produces consistently reliable results and has been demonstrated to meet the specified requirements for its intended purpose.
Temperature at which pressure tests are carried out to establish the MPR for non-metallic reinforced products. NOTE The pipe's temperature rating cannot exceed the maximum qualification temperature.
Pre-production activities are conducted to assess the suitability of a product, design, procedure, or material These evaluations may be repeated periodically as part of a quality control strategy, distinguishing them from production testing or batch release testing.
Statistical procedure to establish a design rating from pressure test results carried out over a long period of time, typically greater than 10,000 hours.
Time of 175,000 hours that is used in this specification to define MPR.
NOTE Pipe's design life may be less than, equal to, or greater than the RCRT.
The primary contributor to the hydrostatic strength of the pipe.
Period of time during which the pipe fulfills all performance requirements.
Burst pressure measured in a short-term test, where pressure is increased at a prescribed rate within a prescribed temperature range.
Pipe that is flexible enough to be spooled into a coil or onto a structural reel for transportation.
NOTE For the purposes of this specification, the terms coils, reels, and spools may be used interchangeably.
Family of composite reinforced pipes in which the structural layer is flexible enough to enable spooling and unspooling.
NOTE This includes, but not limited to, S-GRE and RTP pipe.
3.1.45 spoolable glass reinforced epoxy pipe (S-GRE)
Spoolable composite pipes are characterized by a structural layer made up of balanced helical windings of continuous glass fibers, all embedded in an epoxy thermoset resin matrix.
3.1.46 spoolable reinforced thermoplastic pipe (RTP)
A spoolable composite pipe features a thermoplastic liner reinforced by a structural layer, which is composed of balanced helical windings of reinforcement members This design ensures durability and strength, making it suitable for various applications.
Reinforcement type in which the strength members are typically encapsulated in a matrix material and provided as a flat ribbon.
The ability to identify the origin of materials and parts used to manufacture a product and/or the product processing or manufacturing history.
Abbreviations
LCL RCRT LCL at time RCRT
MAOT Maximum Allowable Operating Temperature
NPR_PV Nominal Pressure Rating of the Product Variant
NPR_PFR Nominal Pressure Rating of the Product Family Representative
P PV1000 1000-hour Test Pressure of the Product Variant
P PFR1000 1000-hour LCL Intercept Pressure of the Product Family Representative
RCRT Regression Curve Reference Time
SMUTS Specified Minimum Ultimate Tensile Strength
SMYS Specified Minimum Yield Strength
Materials Selection
The manufacturer shall be responsible for the selection and supply of all materials so that the materials meet the specified service and installation requirements.
Material Requirements
Sections 4.2.1.1 through 4.2.1.3 are applicable to liner applications and requirements
Polymeric compounds shall conform to the materials requirements listed within the standards listed in Table 1 Fitness for purpose shall be established based upon tests as specified in Table 2.
Master batch addition to the standard resin is acceptable as long as it is the same addition used to qualify the PFR.
Fusion joints in the liner are permitted provided that they are performed by a qualified operator using a procedure qualified according to a recognized standard.
The liner shall maintain its integrity for the specified fluids under the given service conditions.
The final material properties after processing shall be within the acceptable range of properties developed during the qualification program in Section 5.
Special attention is necessary for liner materials that exhibit strong crystallization tendencies It is crucial to adhere to the specific processing parameters outlined in section 6.2 to avoid undesirable alterations in microstructure, which can lead to negative impacts on material properties.
Changes to the liner may require requalification—see 5.6 for additional information.
The manufacturer must document the impact of chemical components in the service environment at the design temperature on liner materials An engineering assessment is required to ensure the liner maintains its integrity and suitability for its intended purpose under design conditions This assessment should be informed by testing and experience, predicting the aging or deterioration of the polymer due to environmental factors At a minimum, estimates of polymer aging must take into account temperature, water cut, and pH levels, with particular focus on issues such as deplasticization, loss or degradation of additives, fluid absorption, and dimensional changes.
Products adhering to this standard must utilize materials that demonstrate stability throughout the product's design life, ensuring they maintain the essential performance characteristics needed to fulfill the original design specifications.
PPI TR-19 may be used as a screening tool for evaluating fluid compatibility ISO 23936-2 and NORSOK M-710 provide a methodology for performing fluid compatibility testing.
The material is demonstrated to resist blistering and other visible damage during rapid depressurization from the Normal Pressure Rating (NPR) and service conditions, following the testing methods outlined in section 6.2.3.3 of API 17J, Fourth Edition Additionally, if the manufacturer specifies a safety factor (F Sn) for gas service, the testing will be conducted at NPR multiplied by F Sn.
If the liner is a multilayer or coextruded structure, the adhesion between layers shall not be compromised during the blistering test.
Section 4 or ASTM F2619-13, Section 4 or API 15LE, 4th Edition, Sections 2 and 5.1.1 or
Standard Specification for Polyethylene (PE) Gas Pressure Pipe, Tubing, and Fittings
Standard Specification for High-Density Polyethylene (PE) Line Pipe Specification for Polyethylene Line Pipe (PE)
Plastics piping systems for the supply of gaseous fuels - Polyethylene (PE)
(Nylons) ASTM D6779 Standard Classification System for and Basis of Specification for Polyamide
Molding and Extrusion Materials (PA)
Standard Classification System and Basis for Specification for Poly (Phenylene Sulfide) (PPS) Injection Molding and Extrusion Materials Using ISO Methods
Standard Classification System for and Basis for Specification for Reinforced and Filled Poly (Phenylene Sulfide) (PPS) Injection Molding and Extrusion Materials Using ASTM Methods
Standard Specification for Polypropylene Injection and Extrusion Materials
Standard Specification for Polypropylene Injection and Extrusion Materials Using ISO Protocol and Methodology
PVDF ASTM D3222 Standard Specification for Unmodified Poly(Vinylidene Fluoride) (PVDF)
Molding Extrusion and Coating Materials
ASTM D5575 Standard Classification System for Copolymers of Vinylidene Fluoride
(VDF) with Other Fluorinated Monomers
PEX ASTM F876 Standard Specification for Crosslinked Polyethylene (PEX) Tubing
NOTE Dimensional requirements do not apply to API 15S applications
Other Polymers ASTM D4000 Standard Classification System for Specifying Plastic Materials
The reinforcement layer, along with its bonding agents, must maintain its integrity under specified service conditions Manufacturers are required to provide documented test data that verifies the layer's short-term and long-term load-bearing capabilities, temperature resistance, fluid compatibility, and aging characteristics of all materials used Additionally, any joints or welds in the reinforcement must be executed following a qualified procedure by a certified operator.
Changes to the structural layer may require requalification—see 5.6 for additional information.
Steel materials used in spoolable pipe shall be purchased in accordance with either a written material specification or an industry standard
Table 2—Property Requirements for Extruded Polymers
Characteristic Tests Standard Liner Reinforceme nt Layer Cover
Properties Resistance to Creep ASTM D2990 X X
Thermal Properties Brittleness (or Glass
Transition) Temperature ASTM D746 or ASTM E1356 X X
Glass Transition Temperature and Melting Point
Characteristics Fluid Permeability API 17J, 4th Edition
Blistering Resistance API 17J, 4th Edition
The manufacturer shall prepare a material qualification report that documents the reinforcement conforms to the specified requirements.
Only materials with the same materials specification (including chemistry and processing history, i.e heat treatment and cold deformation) as used in the qualification testing shall be regarded as qualified.
Steel material selection shall consider corrosive attack appropriate to the environment to which the layer is exposed
Steel reinforcement intended for cathodic protection must undergo qualification testing to ensure that the potential hydrogen evolution from cathodic charging does not lead to hydrogen embrittlement.
Testing will be performed on degreased samples subjected to 75% of their actual yield stress and immersed in de-aerated seawater containing at least 3 wt% NaCl, with an applied potential of 1.05 V versus SCE Cathodic charging will be applied for a minimum of 150 hours, followed by a post-test examination to ensure that no hydrogen blistering or cracking has occurred in the samples.
To qualify products for sour service applications, the steel reinforcement must meet specific threshold limits for Hydrogen Induced Cracking (HIC) and Sulfide Stress Cracking (SSC) These limits should be tested according to NACE TM0177 or the manufacturer's criteria, with the exception that the test fluid must be an aqueous solution saturated with a mixed gas that reflects the equivalent partial pressure.
H 2 S, CO 2, and CH 4 in the annulus;
1) if the manufacturer does not have a verified model for calculating annulus conditions, the pipe bore equivalent partial pressures shall be used;
Testing procedures for polymer-metal composite reinforcements require the use of an inert gas, with tests conducted at ambient temperature for a minimum duration of 720 hours If testing involves polymer-metal composites, the duration must be extended to account for the time needed for corrosives to permeate the matrix material Specimens should be loaded to at least 90% of the Specified Minimum Yield Strength (SMYS), and tensile load tests or four-point bend tests are to be employed Additionally, sample dimensions may vary from TM0177 requirements based on the shape of the reinforcement used.
If applicable, production welds shall be included in steel reinforcements to be qualified for sour service applications
The test samples must endure a 720-hour test without any failures After conducting a SSC test, it is essential to evaluate the steel reinforcement's susceptibility to hydrogen-induced cracking (HIC) as outlined in Section 7 of NACE TM0284-2011 Unless otherwise specified by mutual agreement between the manufacturer and the purchaser, the acceptance criteria are as follows: a) CLR must be less than 15%, b) CTR must be less than 3%, and c) CSR must be less than 1.5%.
For wires or filaments with dimensions under 1 mm² that cannot undergo HIC examination, an axial load failure test must be performed according to ASTM A370 after SSC testing The axial load at failure must satisfy the minimum specified value based on the minimum cross-sectional area and mechanical properties of the reinforcement It is important for the purchaser to recognize that alterations in operating conditions may impact pipe performance.
Fiber must be either roving or yarn and should be acquired based on a documented material specification or industry standard This specification must include essential values and tolerances for physical and mechanical properties Additionally, the fiber must comply with the general reinforcement layer requirements outlined in section 4.2.2.1, with special emphasis on fluid compatibility, particularly concerning hydrolysis and pH effects.
Fibers may be embedded in a matrix
The manufacturer shall prepare a material qualification report that documents the reinforcement conforms to the specified requirements.
Only materials with the same materials specification as used in the qualification testing shall be regarded as qualified.
For glass fibers intended for use in a matrix, the glass fibers shall have a sizing that is compatible with the intended resin
The glass fiber specification shall include filament diameter, strand tex, sizing, and material composition or material family classification.
Aramid fibers consist of filament yarns or polymer-coated tapes, with specifications that must include the short-term breaking load as per ASTM D7269 testing methods Additionally, the linear density of the fiber should be detailed, and for yarns, the twist measured in turns per unit length must also be reported.
Polyester fibers must consist of filament yarns or polymer-coated tapes The specifications should detail the short-term breaking load of the filament or yarn, following the ASTM D885 or D2256 test methods, and include the linear density of the fiber Additionally, for yarns, the twist measured in turns per unit length must be reported.
The matrix material must be acquired based on a documented material specification or industry standard, ensuring it is appropriate for its intended use Any modifications to the matrix material may necessitate requalification, as detailed in section 5.6.
General
This section outlines the qualification requirements for pipe bodies, end-fittings, couplers, and their general characteristics The manufacturer must demonstrate compliance with these specifications and maintain a qualification test report on file, which must be available to the purchaser upon request Additionally, purchasers have the right to conduct further investigations to verify the manufacturer's compliance.
When introducing any type of joints into manufactured pipes, it is essential to use samples with joints in the full qualification procedure or to treat them as a pressure vessel (PV).
Thermoplastic liner butt welds are exempt from this provided the appropriate procedures are followed to ensure consistent high weld quality as described in 4.2.1.1.
For an introduction to terminology used in this section, see Annex H.
According to ASTM D1599, the length of the test specimen must be specified, but for nominal diameters of eight inches or larger, manufacturers may use shorter test specimens if they can technically justify the reduced length.
Pressure Rating of Steel Reinforced Pipe
Steel reinforcement lacks notable regression properties, which is why the Minimum Pressure Rating (MPR) must be determined based on the calculated minimum burst pressure (\$P_{\text{burst, min}}\$) of the pipe, as outlined in section 5.2.5.
The MPR of the PFR and its product variants must be validated through burst pressure testing as outlined in sections 5.2.3.3 and 5.2.5 This testing should be verified and certified by an independent third-party agency compliant with ISO/IEC 17020 and/or ISO/IEC 17065, or conducted at a laboratory accredited to ISO 17025 Additionally, any failed samples, including those that fail for reasons other than the PM, must be documented in the qualification report.
The product family size can vary by a nominal diameter of -2 inches (51 mm) to +4 inches (102 mm) from the PFR, and the pressure rating can range from 1.5 to 2 times the nominal pressure rating of the PFR Any modifications that exceed these limits necessitate a complete qualification as a new PFR, as outlined in Section 5, while changes within these specified ranges are classified as Product Variants.
A PFR shall have a nominal diameter of at least 2 in (51 mm) in accordance with 7.1 and shall be tested in accordance with 5.2.3 to determine properties for the product family
5.2.3 Qualification of the Product Family Representative
All qualification tests from 5.2, 5.4, 5.5, and 5.7 shall be carried out on spool pieces comprising the basic pipe body, together with one or more types of end-fitting
All tests must be performed with unrestrained ends, and laboratory test fittings are permitted For nominal diameters of eight inches and above, manufacturers may utilize shorter test specimens than those specified in ASTM D1599, provided they can demonstrate through technical means that the reduced length is warranted.
Because qualification testing is typically conducted at ambient temperature the manufacturer shall select a MAOT and validate by testing in accordance with 5.4.3.
Test samples must either be preconditioned or meet the criteria outlined in section 5.5.2 If preconditioning is required, samples should be prepared according to the specified allowable handling MBR or the maximum number of respooling cycles, or both, if the tests in 5.5.2 are not successful, before conducting PFR qualification testing.
The MPR of the PFR, as outlined in section 5.2.5, must be validated through burst pressure testing on a minimum of five specimens, following the guidelines in section 5.2.4 The 97.5% lower prediction bound for these burst specimens is determined using the Student's t-distribution For the MPR to be validated, this lower prediction bound must be equal to or exceed MPR/Fd, and no individual test specimen should fall below this threshold For detailed methodology on calculating the 97.5% lower prediction bound, refer to Annex J.
The permissible mode of failure shall be tensile rupture of the reinforcement
If there is a failure mode other than the permissible mode during qualification testing, then that test result shall be discarded in computing averages or plotting the data
NOTE An example of a nonpermissible failure mode is ejection of the pipe from the fitting or coupler.
Short-term burst pressure testing must be conducted following the guidelines of API 17B or ASTM D1599, Method A These testing methods serve the same purpose and can be regarded as equivalent for compliance with the standard.
The test duration may be extended to suit larger diameter and higher pressure products, as well as commonly available pressurization equipment This duration will be a multiple of the range specified in ASTM D1599 and must be documented in the qualification report The same duration range will also be applied for quality assurance testing.
Preconditioning samples for short-term burst characteristics is unnecessary However, if preconditioning is implemented to determine these characteristics, the same preconditioning method must be applied during QA testing.
Manufacturers must conduct burst pressure testing on all pressure vessels (PVs) within each product family, using at least five specimens as per section 5.2.4 The qualification of PVs requires that the 97.5% lower prediction bound, calculated using the Student's t-distribution, exceeds or equals the minimum pressure rating (MPR) divided by the design factor (Fd) For detailed calculation methodology, refer to Annex J Additionally, permissible failure modes must comply with the guidelines outlined in section 5.2.3.4.
The MPR shall be calculated as follows:
P burst, min is the calculated minimum burst pressure.
The manufacturer shall ensure the P burst, min is calculated based upon minimum cross-sectional area and minimum mechanical properties of the reinforcement.
The maximum design factor, \( F_d = 0.5 \), is applicable under specific conditions: the fluid service must be water, static loading is assumed, and installation must adhere to the manufacturer's guidelines For additional information on other fluids, cyclic loading, and proper handling and installation practices, refer to the relevant sections and annexes.
When operating conditions deviate from baseline parameters, further testing or analysis may be necessary Fluid Service Factors, influenced by local regulations and user needs, are not covered in this document For guidelines on F Sn s, please refer to Annex F.
Pressure Rating of Nonmetallic Reinforced Pipe
Nonmetallic reinforcement has significant regression properties For this reason, the MPR shall be based on a design factor applied to the long-term hydrostatic pressure of the pipe
The MPR of the PFR and its product variants must be validated through long-term hydrostatic pressure testing as per section 5.3 This testing should be verified and certified by an independent third-party agency compliant with ISO/IEC 17020 and/or ISO/IEC 17065, or conducted at a laboratory accredited under ISO 17025 Any failed samples, including those that fail for reasons other than PM, must be documented in the qualification report.
Long-term hydrostatic pressure shall be developed and reported adhering to the methodology of ASTM D2992-12, Procedure B.
The product family size can vary by a nominal diameter of -2 inches (51 mm) to +4 inches (102 mm) from the PFR, and the pressure rating can range from 1/2 to 2 times the nominal pressure rating of the PFR Any size or pressure rating changes beyond these limits necessitate full qualification as a new PFR, as outlined in Section 5, while modifications within these specified ranges are classified as Product Variants.
A PFR shall have a nominal diameter of at least 2 in (51 mm) in accordance with 7.1 and shall be tested in accordance with 5.3.3 to determine the regression slope for the product family
5.3.3 Qualification of the Product Family Representative
All qualification tests from 5.3, 5.4, 5.5, and 5.7 shall be carried out on spool pieces comprising the basic pipe body, together with one or more types of end-fitting
All tests must be performed with unrestrained ends, and laboratory test fittings are permitted For nominal diameters of eight inches and above, manufacturers may utilize shorter test specimens than those specified in ASTM D1598, provided they can demonstrate through technical means that the reduced length is warranted.
Test samples must either undergo preconditioning or meet the criteria outlined in section 5.5.2 If preconditioning is required, samples should be prepared according to the specified allowable handling MBR or the permitted number of respooling cycles, or both, if the tests in 5.5.2 are not successful, before conducting PFR qualification testing.
The Minimum Performance Requirement (MPR) of the Pressure-Flow Regulator (PFR) will be established through a series of creep rupture tests conducted at a constant pressure and the specified qualification test temperature The testing procedure will adhere to ASTM D2992-12, Procedure B, and only data points with durations of 10 hours or more will be considered in the regression analysis.
The manufacturer must choose a qualification test temperature that is equal to or exceeds the design temperature for any application of the product.
Water is typically used as the pressurizing fluid If an alternate fluid is used it shall be specified in the qualification report.
The permissible mode of failure shall be tensile rupture of the reinforcement
If there is a failure mode other than the permissible mode during qualification testing, then that test result shall be discarded in computing averages or plotting the data.
NOTE An example of a nonpermissible failure mode is ejection of the pipe from the fitting or coupler.
5.3.4 Establishing Short-term Burst Characteristics
If burst test is used for QA testing as detailed in 6.4, determination of short-term burst properties is required to establish baseline burst strength of a product family
Sets of short-term burst pressure results for the PFR and PVs shall be obtained following ASTM D1599, Procedure A, using at least five samples per set
The 97.5 % lower prediction bound of each set of burst specimens shall be calculated using the Student's t-distribution Refer to Annex J for the 97.5 % lower prediction bound calculation methodology.
The permissible mode of failure shall be tensile rupture of the reinforcement
The test duration may be extended to suit larger diameter and higher pressure products, as well as commonly available pressurization equipment It should be a multiple of the duration range specified in ASTM D1599 This duration range must be documented in the qualification report and consistently applied for QA testing.
Preconditioning samples for short-term burst characteristics is unnecessary; however, if preconditioning is implemented, it must be consistently applied during QA testing.
Manufacturers must conduct tests on all product variants (PVs) within each product family to confirm their classification Field-fittings will be utilized for the testing of these PVs.
5.3.5.2 Qualification of Product Variants Requiring a Two-sample Test
Each PV must undergo a minimum of two samples tested for 1000 hours under constant pressure to ensure performance meets or exceeds that of the fully qualified product Testing will follow ASTM D1598 at the specified qualification test temperature, with both samples required to last the full 1000 hours without failure If retesting is necessary, it will adhere to section 5.8, and any failure to pass the retest will necessitate complete qualification testing.
The test pressure for the 1000-hour constant pressure test for the PV is directly proportional to the 1000-hour LPL intercept pressure of the PFR, and it is calculated accordingly.
P PV1000 = P PFR1000 × (NPR_PV / NPR_PFR) (2)NOTE Additional guidance on scalability of fiber reinforcements is provided in Annex E.
The MPR shall be calculated as follows:
The maximum design factor, \( F_d = 0.67 \), is applicable under specific conditions: the maximum design temperature must be equal to or lower than the qualification temperature, the fluid service should be water (with additional guidance available in Annex F for other fluids), the loading must be static (for cyclic loading, see Annex G), and installation must adhere strictly to the manufacturer's recommendations and requirements, as detailed in Annex D for handling, installation, and operational practices.
If operating conditions are outside these baseline conditions, additional testing or analysis shall be considered.
Fluid Service Factors can be applied to products according to local regulations and user needs, which are not covered in this document For detailed guidelines on Fluid Service Factors, please refer to Annex F.
Field End-fittings and Field Couplings
End-fittings and couplings must be assembled following the manufacturer's written instructions during qualification Additionally, only field-fittings that have been qualified by the pipe manufacturer should be utilized when specified.
The manufacturer shall state and be able to justify the minimum and maximum temperature at which an end-fitting or coupling may be installed on a pipe.
5.4.2 Qualification of Field-fittings for Product Family Representative
5.4.2.1 Field-fittings Used for Testing
If field-fittings are used for testing according to 5.2 or 5.3.3 they are considered to be qualified and testing in accordance with 5.4.3 is still required.
5.4.2.2 Laboratory Fittings Used for Testing
Laboratory test fittings referenced in sections 5.2 or 5.3.3 must undergo testing as outlined in 5.2.5 or 5.3.5, utilizing field-fittings to ensure they do not negatively impact the MPR The sole acceptable failure mode for qualifying field-fittings is the tensile rupture of the reinforcement, and compliance with section 5.4.3 remains mandatory.
To prevent failure modes associated with the polymeric components of pipes in end-fittings or couplings, an elevated temperature test procedure must be implemented This testing ensures reliability from the conclusion of the regression test period throughout the entire design life of the product.
The elevated temperature test must be conducted on photovoltaic systems (PVs) from each product family, ensuring that at least the smallest and largest diameters within each pressure rating group, or the lowest and highest pressures within each size group, are selected for testing.
Consideration should be given to the effect of dimensional tolerances at intermediate diameters
The manufacturer shall subject test samples, with unrestrained field end-fittings or couplings, to a constant pressure test at a temperature in excess of the MAOT as follows:
The time-temperature shift factor, denoted as α, is crucial in determining the relationship between design life and test time The design life, represented as t Design Life, is measured in hours, while the test time, t Test, is also expressed in hours The logarithm, using base 10, is applied to analyze the difference between the test temperature and the product's Maximum Allowable Operating Temperature (MAOT), represented as ΔT.
For polyethylene products, the test duration is determined using an alpha value of 0.112 decades/°C, as outlined in Table 1 In contrast, for other polymers, multilayer liners, or covers made from multiple materials, or in cases of failure modes that are not ductile, an appropriate alpha value must be established, or a default of 0.05 decades/°C can be used.
For steel-reinforced pipes, the minimum test pressure must be 1.5 times the nominal pressure rating (NPR), while for nonmetallic reinforced products, it should equal the lower confidence limit (LCL) at the required critical test (RCRT) The testing period must adhere to specified durations, with water used as the internal testing medium and air or a controlled temperature water bath as the external environment Any alternative media must be documented in the test report It is essential to maintain the test fluid and the outer pipe wall within ±5 °F (±3 °C) of the designated test temperature Manufacturers must ensure that any failures are not due to brittle failure modes, which are unacceptable and must be addressed prior to retesting, conducted in accordance with section 5.8.
EXAMPLE 1 If tDesign Life = 175,000 hours, α = 0.112, and a test time of at least 1000 hours is desired, then the test temperature shall be 36 °F (20 °C) greater than the product's MAOT.
EXAMPLE 2 Assuming the conditions of Example 1, if a test temperature 45 °F (25 °C) greater than the MAOT is to be used, then the test duration is at least 277 hours.
To qualify each fitting or coupler type, a minimum of two end-fittings or couplers must be tested, with the spool piece length adhering to the specifications outlined in sections 5.2.3.1 or 5.3.3.1, as applicable It is essential that all specimens demonstrate no leakage throughout the entire test duration.
After the elevated temperature test, each test piece must be depressurized and stored in ambient air for a minimum of 24 hours Subsequently, the test pieces will be pressurized to 150 psi ±50 psi (1.0 MPa ±0.34 MPa) at ambient temperature and inspected for any leakage It is essential that no visible leakage occurs during the 24-hour observation period Additionally, ambient temperature should be monitored and recorded to assist in understanding changes in the internal pressure of the pipes.
The manufacturer must define the permissible temperature cycling range and perform tests on the highest pressure class of the product family This testing should involve two samples of the smallest and two samples of the largest pipe diameters Specifically, the pipe specimens should be conditioned to the connector's lowest allowable installation temperature and maintained for at least 2.5 hours.
To ensure proper installation, fittings must be installed at the specified temperature according to the manufacturer's instructions The specimen should be conditioned to the Maximum Allowable Operating Temperature (MAOT) for at least 2.5 hours, followed by conditioning to the lower test temperature (MAOT minus the allowable temperature cycling range) for another 2.5 hours This process should be repeated for a total of three cycles Afterward, the sample must be conditioned at ambient temperature for a minimum of 2.5 hours Finally, a pressure leak test should be conducted at 1.5 times the Nominal Pressure Rating (NPR) for at least two minutes under ambient conditions, ensuring no leakage occurs during this time to pass the test.
For bonded pipe constructions, visual examination of the pipe following this test shall show no disbonding.
NOTE The maximum and minimum installation temperature may be different than the maximum and minimum operating temperature.
5.4.5 End-fitting and Coupling Requalification
Changes that affect fit or function shall require requalification in accordance with 5.4.
Determination of Other Pipe System Characteristics
5.5.1 Rapid Decompression Testing of Pipe Structure for Gas or Multiphase Service
Rapid decompression testing must be carried out at the maximum nominal pressure rating and the highest design temperature for the product family This testing will follow the laboratory test method specified in Annex C to ensure that the design of pipes and fittings prevents issues such as collapse, disbondment, blistering, or cover blow-off.
5.5.2 Minimum Bend Radius/Respooling Test
The manufacturer must specify the operating MBR, which is validated through 1000-hour testing for nonmetallic reinforced pipes For steel reinforced pipes, two test specimens must undergo short-term burst pressure testing, ensuring that each burst pressure meets or exceeds the MPR/F d requirement.
The manufacturer shall also conduct tests on the highest pressure class of the product family using two samples of the smallest and two samples of the largest pipe diameter.
The samples shall be tested by being held in a suitable fixture and maintained at the operating MBR during the test Retesting shall be in accordance with 5.8.
When the handling MBR is less than the operating MBR, samples must be preconditioned to the handling MBR before conducting the test outlined in section 5.5.2.1 at the operating MBR If the handling MBR is equal to or exceeds the operating MBR, the requirements of test 5.5.2.1 are considered satisfied In cases of failure, all samples must be preconditioned to the handling MBR before proceeding with PFR qualification testing according to section 5.2.3 for steel reinforced pipes or section 5.3.3 for nonmetallic reinforced pipes.
The impact of handling and spooling on pipe performance will be evaluated by subjecting two samples to 10 bending cycles at the operating MBR This will be validated through a burst test for steel reinforced pipes, as outlined in section 5.2.4, or a 1000-hour test for nonmetallic reinforced pipes, following section 5.3.5.2 Retesting will adhere to the guidelines specified in section 5.8.
If the handling MBR is smaller than the operating MBR, one of the ten conditioning cycles shall be conducted at the handling MBR.
If this test (or the retest) is unsuccessful or if the manufacturer prefers, pipe samples for full qualification shall be conditioned with 10 bending cycles at the operating MBR.
When respooling is permitted, prepare two samples to the manufacturer's specified number of allowable bending cycles for the relevant respooling MBR Validate the samples through a burst test as outlined in section 5.2.4 for steel reinforced pipes, or conduct a 1000-hour test as per section 5.3.5.2 for nonmetallic reinforced pipes Retesting should follow the guidelines in section 5.8.
If the number of respooling cycles is 10 or more and the respooling MBR is less than or equal to the operating MBR, then the criteria outlined in section 5.5.2.3 are met by this test.
If the initial test or retest fails, all samples must be preconditioned to the respooling MBR before conducting PFR qualification testing according to section 5.2.3 for steel reinforced pipe or section 5.3.3 for nonmetallic reinforced pipe.
The manufacturer must define the maximum allowable axial tension load for each pipe variant and validate this through testing If the installation guidelines suggest pulling on pipes with end-fittings or couplings, the manufacturer is required to perform the test on the complete assembled pipe, including these components.
Two samples will be conditioned under the permissible axial tension load without internal pressure for a minimum of one hour, followed by a 1000-hour test as specified in section 5.3.5.2 for nonmetallic reinforced pipes For steel reinforced pipes, two test specimens will undergo short-term burst pressure testing according to section 5.2.4, ensuring that each burst pressure meets or exceeds the minimum required pressure (MPR/F d) Retesting will be conducted in accordance with section 5.8.
The target axial tension load shall be achieved in no less than 1 minute and no more than 20 minutes.
External load performance shall be characterized using ASTM D2412
5.5.5 Minimum Allowable Operating Temperature Test
The manufacturer must define the minimum allowable operating temperature and conduct tests on the highest pressure class of the product family using samples from both the smallest and largest pipe diameters Only field-fittings approved by the pipe manufacturer are permitted The testing process includes conditioning the specimen to the minimum allowable operating temperature for at least 2.5 hours, followed by a pressure leak test at the maximum pressure rating (MPR) and the minimum allowable operating temperature for a minimum of 60 minutes Additionally, a test at 150 psi ±50 psi (1.0 MPa ±0.34 MPa) must be conducted at the minimum allowable operating temperature for at least 10 minutes to ensure the connection's low-pressure leak tightness Gas or liquid can be used as the pressurizing medium, and all specimens must demonstrate no leakage throughout the entire test duration.
Requalification
Requalification shall be required when the manufacturer makes changes to the materials and/or manufacturing process used in any product family.
Using thermoplastic liner or cover materials from various suppliers that meet the standards outlined in Table 1 for PE and share the same ASTM or ISO material designation code will not be considered a change and will not necessitate additional testing For other thermoplastic materials, the ASTM or ISO designation must accurately reflect the essential properties of the qualified material Materials sourced from different suppliers must demonstrate performance consistent with the originally qualified material as specified in Table 2 In cases where no industry-accepted standard exists for thermoplastic materials, any changes to the properties listed in Table 2 will require partial requalification and accelerated life testing of the end-connection system as per section 5.4.3.
Material changes must be justified technically, detailing their impact and requiring partial requalification per Section 12 of ASTM D2992-12 for nonmetallic reinforced pipe This includes a minimum of three failure points between 100 and 999 hours for one set, and three points exceeding 2000 hours for another Steel reinforced pipe must undergo burst testing as specified in 5.2.5 The justification should assess whether the changes negatively affect qualification test results; if uncertain, relevant tests must be repeated alongside partial requalification Should samples fail, manufacturers may opt for retesting per 5.8, but if retest samples also fail, full qualification as per 5.3.3 or 5.2.3 is required.
Changes to the liner or cover as described in Table 3 shall also require accelerated life testing of the end-connection system in accordance with 5.4.3 as a minimum.
A product manufactured in a portable factory with a quality management system compliant with 6.1 for on-site production and setup will not be deemed to have undergone a change in its manufacturing process solely due to the relocation of the factory.
Changes not described in Table 3 shall be subject to full qualification according to Section 5.
Other Required Testing
Certain product properties, described in this section, do not have specified requirements, but are nevertheless important in pipe system design and shall be provided by the manufacturer.
If PE is used for the cover, the UV resistance for transportation and short-term storage shall be Code C or Code E as defined in ASTM D3350 or ISO 4437.
The UV resistance of other cover materials for transportation and short-term storage should be documented and agreed upon between the manufacturer and the purchaser.
For pipe used in surface applications, the UV resistance should be documented and agreed upon between the manufacturer and the purchaser.
The manufacturer must provide the impact energy resistance of the pipe at the minimum installation temperature Two pipe samples will undergo impact testing as per ASTM D2444 using Tup B or an equivalent method After impact testing, the pipe's impact energy resistance will be verified through a 1000-hour test for nonmetallic reinforced pipes For steel reinforced pipes, the two test specimens will be subjected to short-term burst pressure testing, ensuring each burst pressure exceeds MPR/F d Retesting will follow the guidelines outlined in section 5.8.
Table 3—Acceptable Changes with Technical Justification and Partial Requalification
Any change in the qualified polymer compound except by replacement with the same compound from a different vendor
A design change in thickness of liner or cover
All compounds not included in the PFR qualification process must be tested as per section 5.7, unless they are specifically exempted through technical justification Additionally, all compounds are required to be qualified according to Section 4.
Any Acceptable Change shall also be tested in accordance with 5.4.3, and, unless specifically exempt by the technical justification, with other tests from 5.4 and 5.5.
Material supplier Supplier's grade and specification Filament diameter
Thermoset curing system manufacturer Thermoset curing system grade Thermoset T g
Transfer of manufacture from one plant to another or additional manufacturing lines or locations
Transfer from prototype to equivalent commercial production manufacturing
The manufacturer shall also conduct a two-sample test on the smallest and largest pipe diameter for the highest pressure class of each product family.
Following impact testing, the cover shall provide adequate protection to the reinforcement from the external environment.
The manufacturer is required to measure and report the axial thermal expansion coefficient of the pipe over a temperature range of at least 50 °F (28 °C), using test samples that are a minimum of six times the pipe diameter Measurements must be taken unpressurized and at the nominal pipe rating (NPR) In cases where outer diameter (OD) clearance is critical, the hoop thermal expansion coefficient must also be assessed Additionally, a two-sample test should be performed on both the smallest and largest pipe diameters for the highest pressure class within each product family.
5.7.5 Growth and Shrinkage on Application of Pressure
The manufacturer will assess and report alterations in pipe length and diameter as the pipe is pressurized from ambient levels to hydrotest pressure Additionally, a two-sample test will be performed on both the smallest and largest pipe diameters for the highest pressure class within each product family.
Retest Procedure
A qualification test with pass/fail criteria may be subject to this retest procedure.
If any original test specimens do not meet the specified requirements, the manufacturer has the option to conduct retests For each non-conforming specimen, two additional replicate specimens from the same batch must be created and tested Successful retesting occurs when all retest specimens conform to the specified test requirements, thereby satisfying the original testing criteria.
If any retest specimen fails to conform, the specified requirements have not been met.
6 Process and Quality Assurance Requirements
Quality Management System
Products meeting this specification shall be manufactured in a facility that maintains a written quality management system in accordance with API Q1, ISO TS 29001, or ISO 9001.
Extruded Polymer Layers
Extruded polymer layers must utilize materials that either possess a Certificate of Conformance from the resin manufacturer or have been tested and documented by the pipe manufacturer to ensure compliance with the specified standards.
Extrusion of thermoplastic materials must adhere to the manufacturer's documented procedures, ensuring that each process is regulated according to an approved setup sheet This sheet outlines the necessary settings for all critical variables, tailored to the specific material and product dimensions.
The liner shall be free of holes or other defects that could cause a leak or prevent containment of the intended fluids.
Reinforcement
Steel reinforcement materials used in pipes must either possess a Certificate of Conformance to Table 4 from the manufacturer or be tested and documented by the pipe manufacturer to ensure compliance with Table 4.
The specification shall, as a minimum, include required values and tolerances for chemical composition, mechanical, and physical characteristics detailed in Table 4.
A coil consists of a continuous length of steel reinforcement produced from the same forming process and heat treatment batch Qualified intermediate welds used to join coil sections for transport can remain during the winding process onto the pipe, provided they meet the manufacturer's procedures However, if these welds are unqualified, they must be removed during the winding of the pipe.
All nonmetallic reinforcement materials must undergo testing to ensure they meet the specifications outlined in section 4.2.2.3 If the supplier provides a Certificate of Conformance, it must include the actual measured values for each test conducted.
Quality Assurance Tests
Purchasers have the right to assess product performance by requesting a sample, which can then be tested to ensure it meets the specified requirements.
Welds and reinforcement joining practices will be defined in this section as those that impact more than 1% of the total cross-sectional area of reinforcement at any point along the pipe.
The manufacturer is required to perform at least one of the following quality assurance tests: For steel reinforced pipes with welds or reinforcement joining practices exceeding 1%, hydrostatic testing must be conducted as per section 6.4.3 For those with practices below 1%, either hydrostatic testing in accordance with 6.4.3 or batch testing as outlined in 6.4.2 is necessary Additionally, for nonmetallic reinforced pipes with joining practices under 1%, batch release tests must be performed in accordance with section 6.4.2.
Table 4—Steel Reinforcement Property Requirements
Chemical Composition ASTM A751 or equivalent One per batch
Tensile Test ASTM A370 or equivalent Two per coil 1
Dimensions Two per coil 1 d) for nonmetallic reinforced pipe with welds or reinforcement joining practices greater than 1 %, batch release tests in accordance with 6.4.2 or hydrostatic testing in accordance with 6.4.3.
Two samples of pipe body per batch (one cut off from each end) shall be tested.
Batch pressure testing can be conducted using two methods: the short-term burst test and the constant pressure test For these tests, reusable end-fittings, which differ in design from those typically used in the field, may be utilized.
The short-term burst test shall follow ASTM D1599, Procedure A or Procedure B, except that the pressurization rate shall be the same as that used in 5.2.3.3, 5.2.5, or 5.3.4
For steel reinforced pipe, each test specimen's short-term burst pressure shall be greater than or equal to MPR/F d
For nonmetallic reinforced pipe, each test specimen's short-term burst pressure shall be greater than or equal to 90 % of the 97.5 % lower prediction bound value as calculated in 5.3.4.
If one sample fails the batch test due to a burst pressure lower than the baseline value, the retest procedure outlined in section 6.4.2.4 must be followed However, if both samples fail the test, the entire batch will be rejected.
The inclusion of the 90% term for non-metallic pipes acknowledges that initial samples used to determine the lower prediction bound may have been randomly selected from products with above-average reinforcement strength In contrast, the strength of steel-reinforced pipes is based on specified minimum reinforcement strength values.
A constant pressure test can be conducted for either 1 hour or 10 hours at the qualification test temperature The pressure level should be set to the LPL pressure corresponding to the selected duration from the regression curve This testing must adhere to ASTM D1598 standards at the qualification test temperature.
The length of time of the test shall be chosen to coincide with a region of the regression curve where sufficient experimental points are available to ensure accuracy.
If one sample fails the batch test by having a time to failure lower than the corresponding LPL value, the retest procedure outlined in section 6.4.2.4 must be followed However, if both samples fail the batch test, the entire batch will be rejected.
If any specimen from a batch does not meet the specified requirements, the entire batch will be rejected However, the manufacturer has the option to conduct retests on two additional samples from the same batch The batch will be accepted if both retest samples meet the requirements; otherwise, if either or both fail, the batch will be rejected.
The hydrostatic test pressure for steel and non-metallic reinforced pipes must be at least 1.3 times the nominal pressure rating and should cover the entire length of the pipe Unless specified otherwise, potable water is the preferred test fluid, with water quality evaluated against end-fitting metallurgy limitations A dye may be added for better leakage detection, and testing can be conducted with the pipe coiled on a drum It is essential to remove trapped air following the manufacturer's procedures, and safety measures must consider the high strain energy stored in the product Field end-fittings are not necessary for this hydrostatic test.
The pressure must be gradually increased, adhering to the manufacturer's specified rate, up to a maximum of 110% of the nominal test pressure and held until stabilization Subsequently, the pressure should be maintained between the nominal test pressure and 110% for at least one hour, during which no leakage or signs of deterioration should occur Alternative testing methods may be utilized if mutually agreed upon by the purchaser and the manufacturer.
Depressurization must be conducted following the manufacturer's specified test procedure Following this process, a thorough visual inspection of the end-fitting areas is essential to check for any signs of damage or leakage from the pipe and its couplers Additionally, it is important to ensure that as much water as possible is removed from the pipe after the test is completed.