Recommended Practice for Wet and Dry Thermal Insulation of Subsea Flowlines and Equipment API RECOMMENDED PRACTICE 17U FIRST EDITION, FEBRUARY 2015 Special Notes API publications necessarily address p[.]
Scope
This recommended practice (RP) offers essential guidance on the performance, qualification, application, quality control, handling, and storage of wet and dry thermal insulation for subsea applications in the petroleum and gas industries It addresses the inspection and repair of insulation defects and encompasses various installation methods for flowlines, including S-lay, J-lay, and reel-lay Additionally, the guideline considers the design and structural handling of subsea trees, manifolds, pipeline end terminations (PLETs), and flowline jumpers, ensuring the integrity of insulation construction through proper placement of structures, sacrificial anodes, and handling appurtenances.
Annex A specifies the minimum requirements for the performance qualification testing and inspection testing requirements for wet insulation systems (insulations in direct contact with seawater)
Annex B specifies the minimum requirements for the performance qualification testing and inspection testing requirements for dry insulation systems (insulations not in direct contact with seawater)
This document is not intended to address either installation procedures or proprietary fabrication of any particular insulation type.
Applicability
This RP is applicable to the following systems and components:
— christmas tree, valve block, and piping;
The referenced documents are essential for the application of this document For dated references, only the specified edition is applicable, while for undated references, the most recent edition, including any amendments, is relevant.
API Recommended Practice 5L1, Recommended Practice for Railroad Transportation of Line Pipe
API Recommended Practice 5LW, Recommended Practice for Transportation of Line Pipe on Barges and
ASTM C518 1 , Standard Test Method for Steady State Thermal Transmission Properties by Means of Heat
ASTM C1511, Standard Test Method for Determining the Water Retention (Repellency) Characteristics of
ASTM D412, Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension
ASTM D575, Standard Test Methods for Rubber Properties in Compression
ASTM D638, Standard Test Method for Tensile Properties of Plastics
ASTM D695, Standard Test Method for Compressive Properties of Rigid Plastics
ASTM D696, Standard Test Method for Coefficient of Linear Thermal Expansion of Plastics Between −30°C and 30°C With a Vitreous Silica Dilatometer
ASTM D792, Standard Test Method for Density and Specific Gravity (Relative Density) of Plastics by
ASTM D1621, Standard Test Method for Compressive Properties of Rigid Cellular Plastics
ASTM D2240, Standard Test Method for Rubber Property—Durometer Hardness
ASTM D2842, Standard Test Method for Water Absorption of Rigid Cellular Plastics
ASTM D4060, Standard Test Method for Abrasion Resistance of Organic Coatings by the Taber Abraser
ASTM E228, Standard Test Method for Linear Thermal Expansion of Solid Materials with a Push-Rod
ASTM E831, Standard Test Method for Linear Thermal Expansion of Solid Materials by Thermomechanical
ASTM E1269, Determining Specific Heat Capacity by Differential Scanning Calorimetry
SSPC-SP-5 2 /NACE No 1 3 , Joint Surface Preparation Standard: White Metal Blast Cleaning
General
For the purposes of this document, the following terms and definitions apply
Silica aerogel material used for pipe-in-pipe (PiP) insulation
Person or team in charge of applying insulation material in equipment
1 ASTM International, 100 Barr Harbor Drive, West Conshohocken, Pennsylvania 19428, www.astm.org
2 The Society for Protective Coatings, 40 24th Street, Sixth Floor, Pittsburgh, Pennsylvania 15222, www.sspc.org
3 NACE International, 1440 South Creek Drive, Houston, Texas 77084, www.nace.org
Quantity of insulation material produced in a single manufacturing run with identical processing parameters
Certificate of conformity issued by the manufacturer
Layer or layers of material(s) applied on the surface of pipeline and other subsea pressure-containing equipment for mechanical and corrosion protection, thermal insulation, weight control, or other purpose
Organization that possesses ownership of supplied equipment
Any self-contained part of a larger entity
Organization responsible to purchaser for the insulation application
Time taken for a fluid contained within a pipeline to reach a predetermined temperature from a specified start temperature when fluid flow is stopped
Length of pipe left uncoated at each end for joining purposes (e.g welding)
Maximum and/or minimum temperature specified for the purpose of design
Overall physical component or assembly envelope dimensions (length × width × height)
Insulation system not in direct contact with seawater
Reference to a parameter of interest at the end of the specified field lifetime based on conditions given in tender documents
Technical, operational, and environmental parameters characterizing the design and use of equipment
Termination of the ability of an item to perform a required function
Uncoated area that results when two pipe sections or a pipe section and a fitting with coating cutbacks are assembled, by welding or other means, in the field
A purchaser or third-party inspector is permitted to observe specific manufacturing steps scheduled for a particular date, resulting in a temporary halt of the manufacturing process around the designated "hold start date."
A hold in the manufacturing process requires sign-off and approval from the inspection party for the witness point and observed manufacturing steps Production cannot proceed until the inspection has arrived and provided the necessary sign-off.
Discontinuity in a protective anticorrosion coating that exposes unprotected metal surface to the environment
Minimum requirement of the activities for quality control and inspection agreed prior to commencement of work
Any combinations of pretreatment, anticorrosion coating, insulation, and/or protective outer sheath as applicable to achieve the corrosion protection and insulation properties as described in this RP
Any part, component, device, assembly, subsystem, functional unit, equipment, or system that can be individually considered
Thermal conductivity coefficient of heat transmission that measures the heating or loss rate of insulation per surface area
Formulation of materials used by the applicator to build up the insulation system
Specific number of units of insulation elements (such as packages or sheets) used on insulation systems
Organization responsible for the manufacture of insulation material(s)
Document containing data regarding the physical and mechanical properties of a particular material used in the insulation process and guidelines and recommendations for its processing and use
This document outlines essential procedures for safely handling materials, providing critical information for workers and emergency personnel It includes vital physical data such as flash point, toxicity levels, and first aid measures.
NOTE The MSDSs are usually issued in accordance with the applicable regulatory body
Purchasers or third-party inspectors are permitted to observe the manufacturing process at any stage, ensuring that the manufacturing schedule and procedures remain uninterrupted, without the need for approval of the observed steps.
Maximum and/or minimum temperature experienced during installation and operation of the equipment
Company, corporation, enterprise, or part thereof that possesses ownership of supplied equipment
Requirements from the end user dealing with overall operating conditions of the insulation system
3.1.34 precast and half shell insulation
Insulation that is preformed and subsequently affixed to the equipment
Testing conducted at the beginning of production to verify that the manufacturing procedure specification can be successfully followed onsite
Qualification intended to demonstrate the suitability of the insulation system and method of application
Owner organiztion or the authorized agency that purchases the insulation system
Process of confirming by examination, testing, or some other defining evidence that the insulation system meets specified requirements for the intended use as mutually agreed between the parties
Organization that provides based material used on insulation system
Specified maximum period of time the insulation system is in service
Specified maximum period of time the insulation is to be stored prior to installation under prescribed storage requirements
Document in which the functional, performance, operating characteristics, and limits of an item required by customer are stated
Organization that provides and is responsible for insulation material
Local quantity of heat that passes in unit time through unit area of a plate with a unit temperature variation along the path of heat flux
NOTE This is also called the overall heat transfer coefficient
Confirmation that the operational requirements for a specific use or application have been fulfilled, through the provision of objective evidence
NOTE Validation could be achieved by qualification testing and/or system integration testing
Confirmation that specified design requirements have been fulfilled, through the provision of objective evidence
NOTE Verification could be achieved by calculations, design reviews, and hydrostatic testing
Item’s gross weight in air
Insulation systems in direct contact with seawater
A purchaser or third-party inspector is permitted to observe specific manufacturing steps scheduled for a designated date, resulting in a 24-hour pause in the manufacturing process surrounding the announced "witness start date."
The inspection party must sign off on witness points and approve the observed manufacturing steps If the inspection does not arrive within the scheduled time or within 24 hours thereafter, manufacturing may continue without delay.
Abbreviations
For the purposes of this RP, the following abbreviations apply
ITP inspection and test plan
Performance Requirements
It is recommended that the purchaser specify the performance requirements to the supplier as applicable for the insulation system and minimally include the following
When considering insulation requirements, it is essential to address several key factors: the U-value, specifying whether it is based on inner or outer diameter; the necessary cooldown time; and storage conditions Additionally, the design and operating temperature ranges, including maximum and minimum limits, as well as the design water depth, must be defined Understanding the production fluid properties, such as density, thermal conductivity, heat capacity, and flow rates, is crucial, along with the seawater temperatures at both the surface and bottom Other important considerations include the expected service life, environmental conditions during storage and handling, details of corrosion protection coatings, and the maximum dry and wet service temperatures Finally, the method of insulation application should also be specified.
Flowline, Riser, and Pipeline Requirements
When insulating flowlines, risers, and pipelines, it is essential to consider several key factors: the length and wall thickness of the pipe, its internal diameter (ID), and the material from which it is made Additionally, the installation method, whether the application is dynamic or static, and the anticorrosion coating field joint cutback length must be taken into account Furthermore, the design specifications for line pipe insulation cutback length and geometry, as well as the compatible field joint insulation type and geometry, are crucial for effective insulation.
Insulation requirements should include but not be limited to dimensional drawings, the details of the components to be insulated, and the insulation to be applied
Unless specified by the purchaser, items including subsea lifting points, pad-eyes, closure bolting, structural bolting, electronic sensors, ROV access, override, hydraulic stab locations, and other specialty hardware should remain uninsulated, ensuring that access to these areas and features is preserved.
When installing insulation near specific equipment, it is essential for the installer to collaborate with equipment vendors or purchasers to establish the required minimum setback distances and clearances.
NOTE Simple sketches and/or guidance instructions to the installer may suffice for this purpose.
Design Life Requirements
When selecting insulation coatings, it is essential to ensure they are appropriate for the intended application and the system's design life The coatings must meet specific design life requirements, including suitability for long-term use, the ability to maintain acceptable insulation properties at the maximum specified water depth, and the capacity to withstand external water pressure corresponding to that depth.
The specified maximum water depth must be calculated by multiplying the actual water depth by the company's required safety factor Additionally, the production process should ensure the integrity of the anticorrosion layer is preserved, and the materials used must be compatible with cathodic protection The design must accommodate ambient temperatures and allow for thermal expansion and contraction of the pipeline, flowline, riser, and equipment Furthermore, the installation method proposed should be feasible, and the materials should minimize biological oxygen demand through direct degradation or leachant release Lastly, the design must facilitate the specified cooldown period during a shut-in condition, starting from the initial shut-in temperature to the final shut-in temperature, assuming that the internal bores and voids of components are gas-filled, and it should be suitable for application on all relevant surfaces and shapes.
Insulation coating qualification matrices and inspection test frequencies for wet and dry insulations are detailed in Annex A and Annex B, respectively.
Material Requirements
Insulation materials must be clearly labeled with essential details, including the supplier's name, material identification, batch number, date of manufacture, quantity, and compliance with manufacturing requirements Additionally, labels should specify shelf life and storage conditions, safety data, lot number if applicable, and a waste disposal plan.
Contractors should obtain the latest technical data sheets from suppliers, detailing product performance, safety, environmental considerations, and application requirements It is also advisable for suppliers to provide certification for each batch of product used Key material characteristics and performance metrics to consider include density, thermal conductivity, temperature limitations, tensile strength, elongation at break, compression strength, hardness, abrasion resistance, fluid permeability, and aging tests with service life estimations.
The insulation material's performance is defined by specific criteria set by the manufacturer and approved by the company Key factors include thermal diffusivity, ultraviolet (UV) resistance, hydrostatic crush strength, maximum exposure to direct sunlight, fracture toughness (which varies by insulation type), and specific heat.
Acceptable insulation raw materials must be in the supplier's original, unopened, and undamaged containers, stored in a dry and clean location within the recommended temperature range They should meet product quality control test results and be applied within the supplier's specified shelf life Additionally, recertification should only be conducted by the raw material supplier, if feasible, and with mutual agreement from all parties involved.
Field Joints Requirements
Field joints are critical points that can lead to issues with both wet and dry insulation, as they may contribute to heat loss and affect cathodic shielding It is essential for the supplier, operator, and applicator of the insulation system to establish a clear application and installation procedure for field joints before starting the work.
5 Application Process and Quality Control
General
It is recommended that the contractor demonstrates that the insulation system and method of application will fulfill the specific project requirements
Quality Control of Raw Materials
The contractor should obtain from the insulation supplier a certification for each batch or lot of raw material
The certification must include essential details such as the product name, designation, batch number, and/or lot number, along with the quality control test results for each corresponding batch and lot Alternatively, a certificate of conformance (COC) can be provided in place of the test results.
It is advisable to conduct at least one test per batch of material after it has been shipped to the manufacturing facility or contractor work site, where the product is mixed, molded, or fabricated into the required geometric shapes This testing is essential to confirm that the raw materials meet the specified insulation properties before application, unless otherwise approved by the company.
Finally, field joints, precast components, and half shells are of particular concern, and care should be taken during the coating process.
Procedure Qualification Test
A procedure qualification test (PQT) is intended to demonstrate the suitability of the insulation system and methods of application
Test methods, acceptance criteria, and testing frequencies for the PQT should be specified in the inspection and test plan (ITP)
The PQT should be carried out on geometries components or applications similar to those of the project
Previously documented PQT reports may be used for design validation, as mutually agreed between parties
The PQT must incorporate tests to validate the integrity of the proposed repair techniques, including essential assessments of adhesion, density, and hardness It is crucial that all repair materials are appropriate for service and proven to be fully compatible with the original insulation material.
The PQT should be performed on field joints reporting the same data as PQTs and preproduction tests
The contractor must submit qualification documentation as part of the PQT, which includes a detailed description of the insulation system and its necessary thickness to meet the company's thermal performance requirements, along with relevant design data Additionally, the submission should include test data for both the insulation material and the insulation system qualifications, as well as qualification data for the application process.
The PQT data tests and qualifications must verify essential factors including water absorption, creep or compression set, and heat transfer coefficient A full-size thermal insulation performance test is necessary to assess the applied product's thermal performance and facilitate comparison with theoretical cooldown analysis Additionally, it is crucial to evaluate differential temperature effects between external seawater and internal fluid temperatures, thermal expansion effects, and compressibility The adhesion between insulation coating systems, bonding systems, and anti-corrosion coatings should also be tested, along with accelerated aging tests for all materials and their combinations Finally, mechanical strength tests (tensile, compression, bending, etc.) and compatibility assessments of materials with cathodic protection systems, particularly for systems lacking anticorrosion coatings beneath the insulation, are imperative.
Manufacturing Procedure Specification
A manufacturing procedure specification (MPS) should be qualified by a PQT The manufacturing operation should be performed by the applicator in accordance with the MPS
The MPS must include essential documentation such as the scope of the project, a comprehensive step-by-step description of the manufacturing process, and details on PPT inspection and ITP Additionally, it should outline critical process parameters that influence material properties, incorporate acceptance criteria within the ITP, and specify handling and storage procedures.
During production, it is essential to implement all critical parameters recorded during the PQT Strict adherence to applicable storage, mixing, application procedures, and potting and curing times is necessary for insulation systems Surfaces intended for permanent coating must be prepared according to the insulation manufacturers' recommendations to ensure optimal adhesion Components that should not be insulated to maintain their functionality must be properly masked and protected during the insulation application Additionally, areas like threads, nuts, and flange interfaces that may need disassembly for repairs should be treated with a suitable release compound, if feasible, before applying the insulation coating to facilitate easier removal later.
When applying insulation systems that generate heat during mixing, it is crucial to prevent cracking of the coating due to differential cooling, especially when applying a thick coating to a cold surface Regular measurement of the insulating coating thickness is essential, utilizing appropriate methods such as magnetic induction, eddy current, or ultrasonic techniques on all coated components.
Inspection and Test Plan
The contractor must prepare the Inspection and Test Plan (ITP), which requires approval from the company It is advisable to present the ITP as a flowchart that highlights the inspection points and their positions within the process, indicating where conformance of characteristics is necessary Additionally, the ITP should clearly outline all inspection activities and tests.
(including frequency and acceptance criteria) The contractor should include additional inspection points for the contractor's own verification of quality, which will be subject to approval
A column for the company to identify the following inspection points is recommended to be included on the
The Inspection Test Plan (ITP) outlines key inspection points and defines the roles of M (monitor), W (witness), and H (hold) regarding notification requirements For domestic locations, notifications for W or H points must be provided at least 10 calendar days in advance, while for foreign locations, a minimum of 15 calendar days' notice is required.
Operators Certification
The contractor should ensure that the personnel involved in the insulation operation are trained and qualified
The qualification training program and training records should be available for company review.
Preproduction Test
A Production Performance Test (PPT) should be conducted at the production site to verify the Product Quality Test (PQT) at the start of production The PPT initiation point is designated as M, W, or H for the purchaser or third-party inspector It is essential that the PPT occurs in the presence of a purchaser representative and adheres to the Inspection and Test Plan (ITP) The PPT may involve a series of nondestructive or destructive quality control tests, and if destructive tests are necessary, it is advisable for the purchaser to increase the total quantity of insulation to be acquired.
Production Tests
The contractor should conduct inspection and testing during production in accordance with an ITP to verify the surface preparation and insulation application A COC may be substituted for test results.
Test Failure
In the event that a parameter measured fails to meet the acceptance criteria for a specified test, the parameter may be reevaluated and/or rechecked.
Process Certification
The contractor should ensure that process equipment/methods are consistent with PQT All equipment should be operable with maintenance records
General
Handling, storage, and transportation procedures should be according to supplier’s recommendation This information should be included in supplier’s fabrication package specification
The supplier should provide effective packaging for fabricated insulation in order to prevent damage during normal storage and shipment via road trailer or sea container.
Purchaser Free Issued Materials
When unloading piping, it is essential to input the pipe identification, including the mill and heat number, into the contractor's pipe tracking system This system must provide a comprehensive audit trail that tracks the pipe from receipt through the insulation process to shipping.
During the storage and insulation application, the pipe should be handled in a way to prevent damage to the pipe body and ends.
Insulation Materials Handling
When handling and storing insulation materials, it is essential to follow safety regulations and the recommendations provided by the supplier Materials should not be utilized past their expiration date unless they have been recertified by the manufacturer and approved by the buyer Any insulation with damaged packaging, an expired shelf life, lack of traceability, or signs of contamination or deterioration must be rejected.
Final Product Handling and Storage
When handling insulated parts, it is essential to follow the supplier's recommendations and use wide soft slings, padded end hooks, or padded lift forks to prevent damage Ensure that handling devices are free from sharp pointed components like bolts or rivets Additionally, be mindful that exposure to sunlight and environmental factors can impact material performance, which should be taken into account during storage.
To ensure the integrity of insulated parts during temporary storage and handling, it is crucial to protect them from damage When loading pipes, adherence to API 5L1 or API 5LW standards is essential Additionally, any alternative transport methods must comply with relevant standards and government regulations.
Documentation Prior to Commencement of Work
Documentation prior to commencement of work should include the following: a) quality plan and ITP, b) project-specific MPS (including handling and storage procedures),
Other project-specific MPS documentation may encompass essential elements such as environmental controls, insulation procedure qualifications, and personnel qualifications Additionally, it includes insulation material and system qualification reports, PQT, material certificates, piping and equipment tracking systems, and PPT results.
Documentation at Delivery of Work
At the time of delivery, documentation must include approved copies of the documents specified in section 7.1, a unique identification number for each coated equipment or pipe, and production testing results alongside individual test results.
Documentation Submittal Schedule
A documentation submittal schedule, as presented in Table 1, is recommended
As-built manufacturing data book
Marking
Suppliers must provide and agree upon general marking requirements with the company It is essential for suppliers to maintain comprehensive documentation for each production run of raw materials, which should include batch numbers and production run dates.
Each insulation package must feature clearly visible labels that stand out against the background color of the insulation material These labels should include the supplier part number, the supplier name, and, if relevant, the orientation for installation, such as "This Side Up."
Recommended Performance Qualification Testing and Inspection
Testing Requirements for Wet Insulation Systems
This annex includes recommendations for performance qualification testing and inspection testing requirements for wet insulation systems
A.2 Performance Qualification Testing for Wet Insulation Systems
This section identifies the minimum recommendations for performance qualification testing to be used for wet insulation systems Table A.1 identifies the recommended performance qualification matrix for wet insulation systems
Table A.1—Performance Qualification Matrix for Wet Insulation Systems
Material Property Test Specification c Room
Water absorption ASTM D575 and/or D2842 x x x
Tensile properties ASTM D638 and/or D412 x x x x
Compressive strength ASTM D695 or D575 or D1621 x x x x
Coefficient of thermal expansion ASTM E228, E831, and/or D696 x x
Weathering and UV resistance See A.2.3 x
Fatigue testing See A.2.5 x a See A.2.2 b If agreed between parties a test procedure based on ASTM C351 (withdrawn) could be used c Alternative test specifications may be proposed by the supplier for approval
The aging test aims to assess and forecast the long-term properties of insulation materials, ensuring they meet the expected thermal insulation performance Contractors are responsible for implementing appropriate material and system aging test procedures that accurately reflect the design life of insulation systems in subsea environments.
Real-time weathering and UV resistance data can be accepted The procedure should be mutually agreed between the parties
A.2.4 Bend Test (Flowlines and Risers)
A bend test must be performed on a full-size, production-quality sample, including a field joint, to ensure proper bonding and integrity between the field joint, the parent material, and the anticorrosion coating.
The qualification process must encompass bending and straightening trials to ensure the system's effectiveness for S-lay, reel-lay, and J-lay installation methods A full-scale bending test setup should accurately replicate the reeling and straightening cycles experienced by a pipeline during installation Additionally, the guiding shoe's radius of curvature must be equal to or less than the installation vessel's reel hub radius, which should be established when selecting the installation contractor.
The test pipe sample should be cooled to approximately 4 °C (40 °F) prior to start of bending and the test sample should be left on the reel in the bent position overnight
The field joint must be positioned so that its interface with the parent material aligns with the maximum strain point To accurately replicate the strain on the pipe during its passage through the straightener, the test string should undergo reverse straining to a curvature that ensures the pipe remains straight when unloaded This bend-straighten process should be executed four times.
After bending, it is essential to visually inspect the coating and field joints for any visible cracks There should be no disbondment between the anticorrosion coating and the insulation material, as well as between the field joint and the parent insulation material To ensure integrity, field joint sections must be cut and sectioned to check for any internal cracks.
A.2.5 Fatigue Testing (Optional for Risers)
Dynamic fatigue testing is essential for assessing the integrity of insulation systems The test sample must be at least 6 meters (20 feet) long and include the proposed field joint Key testing parameters include a strain of 0.2%, 1,000,000 cycles at a frequency not exceeding 10 Hz, and conditions of ambient temperature and atmospheric pressure.
The acceptance criteria should be that there is no cracking or disbondment of the insulation upon visual inspection
Adhesion between all interfaces of the insulation system, including field joint and precast and half shell insulation, should be verified Testing should be performed as agreed between the parties
The test procedure should be submitted to purchaser for approval
A.3 Inspection Recommendations for Wet Insulation Systems
This section identifies the minimum recommendations for inspection of wet insulation systems Table A.2 identifies the recommended inspection frequency and acceptance criteria for wet insulation systems
Table A.2—Inspection Frequency and Acceptance Criteria for Wet Insulation Systems
Property Inspection Frequency Acceptance Criteria
Environmental conditions Once per hour >3 °C (5 °F) above dew point
Surface condition before preparation Each pipe/component Free of holidays, damage oil, and grease deposits Surface condition after abrasion a Each pipe/component Uniform abrasion
Primer ratio a Each mix +2 % of coating supplied stated ratio
Primer application Each pipe/component Supplier to advise recommendation
Preheat temperature Each pipe/component Supplier to advise recommendation
Sample for gel time and mixture quality a Each shift Supplier to advise
Cutback length Each pipe/component Company to advise
Mold temperature Each pipe/component Supplier to advise
Mold removing time a Each pipe/component Supplier to advise
Visual examination Each pipe/component Per A.3.3
Thickness examination Each pipe/component
As per ITP agreed with purchaser/company (e.g target thickness +5 % nominal: >1 % target thickness)
Hardness examination Each pipe/component Supplier to advise
Sounding a Each pipe/component No audible change in tone
Adhesion Once per shift Supplier to advise
Density Once per shift Supplier to advise
Cross section examination Twice per shift
As per agreements with client on ITP (e.g free of delamination, disbondment, porosity, voids, or blisters), samples to come from first and last specimens
Thermal conductivity a 1 in 400 pipes and/or material batch Company to advise Measure concentricity at the pipe ends Each pipe/component Company to advise a Requirement based on type of insulation
A comprehensive visual inspection (100%) must be conducted on every insulated component The coating should be devoid of blisters, frosting, holidays, scratches, voids, porosity, or any other defects that could compromise its insulation function, and it should exhibit a consistent color throughout.
There should be no visual evidence of disbondment between the anticorrosion coating and the steel and between the anticorrosion coating and the insulation layer
Recommended Performance Qualification Testing and Inspection
Testing Requirements for Dry Insulation Systems
This annex includes recommendations for performance qualification testing and inspection testing requirements for dry insulation systems
B.2 Performance Qualification Testing for Dry Insulation Systems
This section identifies the minimum recommendations for performance qualification testing to be used for dry insulation systems Table B.1 identifies the recommended performance qualification matrix for dry insulation systems
Table B.1—Performance Qualification Matrix for Dry Insulation Systems Material Property Test Specification e Room Temp Max Temp Min Temp Aged Values a
Tensile properties ASTM D638 and/or D412 x x x x
Bend test See B.2.7 x a See B.2.2 b See B.2.4 c If agreed between parties, a test procedure based on ASTM C351 (withdrawn) could be used d See B.2.3 e Alternative suitable methods may be proposed by supplier
Dry insulation density testing is conducted depending on the dry insulation type The supplier should advise on the type of insulation density testing to be used
Thermal conductivity testing should be performed in accordance with ASTM C518 or an equivalent test to be proposed by the supplier and approved by the company
The k-value of insulation must be assessed for each individual ply, if relevant It is essential to take two measurements for every batch of insulation materials produced All measurements should be conducted and documented for every manufactured lot.
Dry insulation diameter measurements should be based on diameter of reference pipe (OD of internal pipe for PiP systems) The thickness is to be within ±5 % of nominal
If applicable, a hydrophobicity testing procedure should be advised by the supplier
Each lot of manufactured insulation materials must undergo two measurements, which should be performed and documented for all lots The testing process involves spraying a small stream of water onto the insulation surface and assessing the bead geometry Successful beading of the water indicates a pass.
B.2.7 Bend Test (Flowlines and Risers)
B.3 Inspection Recommendations for Dry Insulation Systems
This section identifies the minimum recommendations for inspection of dry insulation systems Table B.2 identifies the recommended Inspection frequency and acceptance criteria for dry insulation systems
A comprehensive visual examination (100%) is essential to identify gaps in insulation, assess spacer requirements, and evaluate other components of the dry insulation system It is important for the supplier to offer guidance on the minimum standards for visual inspections.
Table B.2—Inspection Frequency and Acceptance Criteria for Dry Insulation Systems
Property Inspection Frequency Acceptance Criteria
Thickness on assembled package Per lot Supplier to advise
Thermal conductivity Per lot Supplier to advise
Hydrophobicity a b Per lot Water must bead
Density Per lot Supplier to advise
Width and length a Twice per shift (beginning and end) Supplier to advise
Overall dimension before installation a Per shift See B.3.4
Overall dimension after installation a Per shift See B.3.5 a If applicable b AEROGEL only
To ensure complete coverage of the flowline, insulation plies should be precisely cut to size when using insulation prepackages or assembled layers Automated ply cutting requires validation of accuracy at the start and end of each shift, necessitating the measurement and recording of individual ply dimensions Additionally, all plies must undergo visual inspection using assembly tooling to maintain quality standards.
The supplier should advise the individual ply dimensions and tolerances
To ensure the effectiveness of insulation systems made from prepackaged materials, it is essential to verify the total thickness of the assembled thermal insulation package using a reference probe Measurements should be conducted with the package laid flat on a table, and at least one thickness measurement should be taken from each assembled panel It is advisable to document the thickness of the first and last panels produced during each manufacturing shift.
The supplier should provide recommendations for the assembled package thickness and tolerances
[1] API Specification Q1, Specification for Quality Management System Requirements for Manufacturing
Organizations for the Petroleum and Natural Gas Industry
[2] API Specification 5L, Specification for Line Pipe, 44th Edition
[3] API Specification 17D, Design and Operation of Subsea Production Systems—Subsea Wellhead and
[4] API Recommended Practice 17Q, Subsea Equipment Qualification—Standardized Process for
[5] ASTM D3418 4 , Standard Test Method for Transition Temperatures and Enthalpies of Fusion and Crystallization of Polymers by Differential Scanning Calorimetry
[6] ASTM E228, Standard Test Method for Linear Thermal Expansion of Solid Materials With a Push-Rod Dilatometer
[7] ISO 9000 5 , Quality Management and Quality Assurance Standards
[8] NACE SP0274 6 , High Voltage Electrical Inspection of Pipeline Coatings Prior to Installation
[9] NACE RP0287, Field Measurement of Surface Profile of Abrasive Blast Cleaned Steel Surfaces Using a Replica Tape
[10] NACE RP0394, Application, Performance, and Quality Control of Plant-Applied, Fusion Bonded Epoxy External Pipe Coating
[12] SSPC-SP-10/NACE No 2, Near-White Blast Cleaning
4 ASTM International, 100 Barr Harbor Drive, West Conshohocken, Pennsylvania 19428, www.astm.org
5 International Organization for Standardization, 1, ch de la Voie-Creuse, Case postale 56, CH-1211 Geneva 20, Switzerland, www.iso.org
6 NACE International, 1440 South Creek Drive, Houston, Texas 77084, www.nace.org
7 The Society for Protective Coatings, 40 24th Street, Sixth Floor, Pittsburgh, Pennsylvania 15222, www.sspc.org.