the increased utilization and acceptance of composite ... · in the up and down stream sectors for...

The increased utilization and acceptance of composite technology for piping and pipelines repairs

in the up and down stream sectors for maintaining asset integrity. visit www.clockspring.com of 11

The increased utilization and acceptance of composite technology for piping and pipelines repairs in the up, mid and

downstream sectors for maintaining asset integrity.

DimasSatyaLesmanaS.T.1

1Regional Manager (Asia Pacific), Clock Spring Company L.P. USA, E-mail: [email protected]

Abstract

Composite repairs are categorized as a recent innovation when it comes to repairing and rehabilitating piping & pipelines with an increasing number of applications now in service. The use of composite technologies for repairing steel pipe has gained a large amount of support and acceptance as a viable option for owners/operators. This acceptance has come because of composite repair system manufacturers completing thorough testing programs to qualify and validate various composite repair systems and composite architecture. This paper is to address the increased utilization and acceptance of composite technology for the up, mid and downstream operator and the benefits of using composite materials as a methodology for temporary and permanently repairing piping and pipelines especially where harsh environment has been damaging the piping and pipeline and affecting its integrity. Composite Repair Technology When considering a repair for piping and pipelines, composite repair may be one of the engineer repairs of choice. This technology can

be a cost-effective method of improving safety while keeping maintenance cost down. Clock Spring Company is also aware that not all composites are of equal character and pedigree and that only Clock Spring meets the engineering and testing guidelines established in recent code revisions. The distinctions between different types of composites used for pipeline repair are important, and must be understood to ensure the composite repair selected will meet the rigorous specifications demanded by sound engineering. There are many different types of composite pipe repair available on the market all of which are extremely different and have undergone different levels of testing, research and onward development. On the market, today there is a great deal of confusion as to which type of composite repair should be used on piping or pipelines with many choices of fiber, architecture and resin available. Composite Sleeve type repairs are accepted in the ASME B31.4 and B31.8 codes as being suitable for the repair of high pressure gas and fluid pipelines but with the introduction of the ISO TS 24817 and ASME PCC 2 article 4.1 guidelines many composite wrap type repairs have entered the market.



Application Consideration Two application techniques are available for the repair of pipelines using composites: first is the Composite wraps (wet applied cloth) and second is the Composite Sleeve (full-cure) system. Composite Wraps - Wet Applied Cloth (Wet Wrap) This repair takes the form of a flexible cloth, woven from e-glass, which is impregnated with resin at the repair site. The e-glass provides the strength needed in the repair and the resin provides the bonding matrix to hold the repair in place and protect the glass from long-term effects of the environment. The disadvantages are obvious. The ratio of resin to glass, the degree of resin saturation, the alignment of the glass and consistency of tension in the repair are difficult to control. Even the number of wraps is a variable that can be changed in the field. All mechanical properties are variable and can be influenced by the installation process. Woven cloth can allow moisture to 'wick' into the composite and weaken the repair. Effectiveness and long-term performance are unpredictable. The advantage is that this repair technique can be used on irregular shapes and fittings.

Wet wrap is an effective repair for pipelines operating at less than 500 psi (3.5 MPa) and for repairing fittings and irregular shapes. It is most often applied in the downstream sector such as plants and refineries where operating pressures are limited. Composite Sleeve Application (Full cure) Clock Spring eliminates all the variables of the wet wrap process. The composite sleeve is

manufactured under controlled conditions. The fully cured composite sleeve is taken to the repair location and secured to the pipe using adhesive. To ensure proper load transfer all defects and voids under the composite sleeve are filled with a high compressive strength filler material. The ratio of glass to resin is accurately controlled and monitored. The unidirectional glass strands are carefully positioned and aligned to maximize strength in the hoop direction. The composite is squeezed, dried, heat-treated and cured and shipped as a completed unit to the repair location. All design variables are controlled. The mechanical properties of the composite sleeve are consistent and well defined. The Clock Spring composite laminate layers are nominally 0.065-inches thick and have a glass fiber content ranging from 65 to 75 percent by weight (45 to 55 percent by volume). The Clock Spring composite sleeve material exhibits linear elastic behavior up to the point of failure in tension, typically 1.5 to 2 percent strain. Typical values of the elastic modulus are 5 x 106 psi in the fiber direction and 1.4 x 106 psi in the transverse direction. Tensile strength is typically 75-100 ksi. The coefficient of thermal expansion is 6.0 x 10-6 inch/inch/°F in the fiber direction and 3.2 x 10-5 inch/inch/°F in the transverse direction. A completed repair will contain 8 wraps of composite. The adhesive has a lap shear strength of 1200 psi and the filler a compressive strength of 8000 psi. Because all variables are well controlled the performance of the Clock Spring repair can be predicted. Without this predictable performance, long-term durability would be questionable. The full-cure composite sleeve (Clock Spring) is designed and tested to ensure a minimum fifty-year life under worst-case environmental conditions of fully saturated soil.



Code and Standard Review on Composite Repair Technology Engineer mostly refer piping repair system to API 570 / ASME B31.3 and pipelines repair system into ASME B31.4 (for liquid) or B31.8 (for gas). Both of API and ASME has establish code for composite or nonmetallic repair for piping or pipelines. Other supporting code is ISO and PRCI (Pipeline Repair Council International). Composite repairs have been successfully utilized by up, mid and downstream operators from a small, medium to a large diameter piping and pipeline to effectively return the integrity of the pipe using both Composite Sleeve and Composite Wrap Repair System. Below is a table guideline for code and standard reference for composite repairs for piping and pipelines:

Type Code Section Type of

Defect

Type of

Repair

Composite Type

Piping API 570 Piping Inspection Code

Section 8.1.5 – Non-welding Repairs (On-Stream).

External Corrosion

Temporary Repair Only

Composite Wrap / Sleeve

Pressure Equipment and Piping

ASME PCC 2

Article 4.1 Nonmetallic Composite Repair Systems for Piping and Pipework: High-Risk

External and Internal Corrosion

Temporary and/or Permanent


Applications

Piping ISO 24817

All Section


Temporary and/or Permanent


Pipelines ASME B31.4 (Liquid and Slurry)

Table 451.6.2.9-1 Acceptable Pipeline Repair Methods

External corrosion ≤ 80% wall loss and Non-Leaking Only

Permanent up to 80% wall loss

Composite Sleeve

Pipelines ASME B31.8 (Gas Transmission)

Table 7.1-1 Acceptable Threat Prevention and Repair Methods

External Corrosion

Permanent up to 80% wall loss

Composite Sleeve

Pipelines Pipeline Research Council International (PRCI) REV 6

3.4 – Defect Repair Using Composite Reinforcement Sleeves Table 1. Summary of repair options for various types of defects.


Permanent Repair up to 80% wall loss

Composite Sleeve

Table 1. Code and Standard Review and comparison

The above code and standards have made significant influence in the acceptance of composite repair for piping and pipelines



operator around the globe. Engineer have options to refer to the code and standards to justified the use of composite technology as an alternative repair within their asset integrity management system. Case Study Application Upstream Case Study #1: Offshore 42” Skim Pile Leak Repair – Temporary Repair External corrosion due to harsh sea environment caused a leak on a 42” skim pile at the splash zone area and in needs of temporary repair as per related code and standard to maintain the integrity. The platform is in the Natuna Block. Following grit blasting and surface preparation in accordance to industry standard guidelines a full cured composite laminate repair was applied to seal the leak and reinforce the general corrosion area. The repair was completed within 1 day.

Figure 1. Completed 42” Skim Pile repair

Upstream Case Study #2: Deck Plate Corrosion Problems – Permanent Repair Offshore operations throughout the world have facing many issue, and corrosion is always a big concern in daily asset integrity issue. The salty atmosphere around is ideal for

corrosion took place and causing problems at any ferrous metal in the offshore platform. One of common issue that took place is corrosion within pipeline and it’s supporting area like deck plate. In some instance, corrosion at deck plate might migrated to any pipeline or piping system that is not well protected. In some case, main riser or main piping system that is goes through a deck plate may have severe corrosion issue. Repair method at this pipeline defect will requires an engineered critical assessment (ECA) which must be done online without the need to shut down the system to avoid potential loss in daily oil and gas lifting target.

Fig 2. Corrosion at deck plate area

Following engineering design in accordance to ISO TS 24827,tThe obstacle at the repair zone (i.e. deck plate steel floor) needs to be removed by any means to allow the technician to do the repair application. The repair will require 6 layers to maintain the integrity with assumption 100% wall loss. Following the removal of the deck plate and cleaning of the 16” pipe, the Clock Spring composite wrap system is installed over the defect zone to provide structural reinforcement on the pipeline.



Fig 3. Clock Spring Contour installed

The pipeline now has been restored and rehabilitated back to its pristine conditions to maintain the integrity without interrupting the production operations. Midstream Case Study #1: 32” Mechanical Damage Repairs – Permanent Repair An external defect suspected due to mechanical damage by backhoe loader during pipeline installation was found after MFL inspection for a main 32” gas transmission line supplying gas from Sumatera to Java – Indonesia an in needs of online permanent repair accepted by ASME B31.8 code to maintain the integrity.

Figure 4. Defect in the 32” pipeline also affecting the seam weld

Following excavation and manual surface preparation in accordance to industry standard guidelines a composite repair sleeve was applied to reinforce the damaged area.

Figure 5. Installation of the 32” seam sleeve

The repair was completed under the supervision of a Clock Spring installer within 1 day. Midstream Case Study #2: High Pressure Gas Transmission Line Repair - Mechanical Defect During routine excavation the excavator accidentally hit a 28" main gas transmission line situated at in the middle of the Perawang jungle in Pekanbaru – Riau, Indonesia. The excavator had "caught" the pipeline causing a significant mechanical defect with 8 meters of the pipeline being damaged. As the pipeline is the main supply to a local power station and also to Singapore, it was critical the pipeline remained in operation, it was mid Summer with temperatures in excess of 39 oC and a peak period for electricity supply. A large number of studies have been conducted concerning the suitability of full cure laminate composite sleeves for the



permanent repair of mechanical damage and third party interference. The results of these studies have shown that Composite Sleeve repairs are acceptable as per ASME B31.8 Table 7.1-1 Acceptable Threat Prevention and Repair Methods.

Figure 6. Completed composite sleeve repair

Downstream Case Study #1: Complex Geometry Repairs – Temporary Repair This repair considers the reinforcement of 60 meters of multi Diameter - 36” to 72” pipe which involved geometry complex such as tee, bend, clamp, flanges, valve, bolt and nuts. The lines are suffering from internal and external corrosion and require a pressure containing composite repair to contain pressure when the internal corrosion goes through wall, lifetimes of 20 years are considered by the operator. This repair required using composite wraps technology in accordance to the guidelines of ISO TS 24817. The repair has been designed to the design pressure of the lines (11 Barg pressure). The repairs is completed using Clock Spring Contour’s (CSC) bi-axial and quad-axial fiber glass and epoxy resin which has undergone

extensive testing at Oxford Brookes University in accordance with ISO 24817. The repair will only perform as designed if adequate surface preparation is completed. It is recommended that good sections of pipe are blasted to a finish equivalent to SA 2 ½ (the axial extent and taper), poorer sections of the pipe are cleaned by power brush to ST3. As much of the pipe as possible is cleaned to SA 2 ½ or equivalent as possible.

Figure 4. Leaking Sea Water Line in need of repair Assessment of the Repairs and Derivations of Thickness Required Based on ISO TS 24817 The assessment has been undertaken based on guidance contained in ISO TS 24817. The repair designed is based on a pressure of 11 Barg and a temperature of +35°C for a 20 years lifetime. The design has been based on the composite carrying circumferential (hoop) and axial loadings, and has also been calculated for the capacity to handle leaks through holes. The calculations completed are presented and discussed below. The repair design was performed in accordance with section 6.5.7 Design of repairs for through wall defects (defect type B) of the ISO 24817 2006 document. The calculations used to establish the t (minimum thickness of



repair laminate required) value were equation 11 which is for circular of near circular defects and equation 12 for circumferential slot type defects. Equation 11 and 12 are to be partnered with Equation 6 and Equation 7 of the ISO 24817 document and the highest value of the 4 equations is the minimum thickness which should be applied as a repair. Copies of equations 11, 12, 6 and 7 are shown below: Equation 11:

Equation 12:

Equation 6 & 7:

This solution considers a temperature range between -0 and +35°C and a maximum pressure of 11 Barg. The repair thickness should be the higher value of all the outputs from equations 11, 12, 6 and 7. Based on the calculation, a minimum repair thickness of 16.8 mm is required (8 layers) for a 20 year lifetime. A total of 9 layers should also be applied at bends location to conform with the ISO TS 24817 guidelines. The Composite Repair Application

Proper surface preparation is essential for the repair to perform as required. As much of the pipe is reasonably practicable should be cleaned to SA 2 ½ (grit blasting), with the full axial extent and taper prepared to Sa 2.5 with a roughness of 50 microns. Clock Spring advise that inspection should carry out further inspections of the pipe and highlight areas which can and cannot be cleaned by blasting. Areas too thin for blasting but thick enough for preparation should be cleaned by power-brush to ST3, areas which are excessively thin should be protected during the cleaning of the line. Clock Spring Contour (CSC) is the latest advanced composite repair technique from the Clock Spring Company. It is ideal for the repair of elbows, tees, reducers, nozzles and other pipe components. The flexible repair technique allows materials to be tailored on-site to enable repair of complex geometrical shapes commonly found in pipe systems. CSC has been developed and is an engineered repair; each application is designed in accordance with industry standards (e.g. ISO TS 24817 and ASME PCC-2 R&T Article 4.1). The Contour system provides a highly durable repair with excellent chemical resistance. Based on high-performance, non-woven glass fiber fabrics and epoxy resin, Contour can provide protection from external and internal corrosion, replacement of strength for damaged pipes and can seal leaking defects. Only installers who have been trained and certified by a Clock Spring trainer are permitted to install any Clock Spring Contour product, in line with section 7 of ISO 24817. The application must follow the method statement of section 7.4 of ISO 24817 which describes the main procedures to be carried out prior to and during the repair system application.



The repair of substrates using composite repair systems differs considerably from other repair techniques and the quality of the installation depends strongly on satisfactory craftsmanship. Annex I of ISO 24817 outlines the basic skills and experience required to install the repair. The sea water line repair installation was completed by Twenty (20) mans crew under the supervision of a Clock Spring installer within 21 days.

Figure 5. First 4 layers being installed

Figure 6. Completed repair at third week

Downstream Case Study #2: Leaking Oil line – Temporary Repair A major downstream refinery is having a 24” leaking crude oil pipeline. Following ASME B31.4 standard, a temporary repair was being taken by applying composite sleeve repair for a temporary 2 years lifetime. Following surface preparation by grit blasting, the leak was plugged using rubber plug and patched using plastic steel putty.

Figure 7. Pinhole leak plugged using rubber plug

The repair then apply 8 layers of Clock Spring composite sleeve repair kit was applied to reinforce the defect area. The installation was completed by three (3) mans crew under the supervision of a Clock Spring installer within 2 day.



Figure 8. Completed repairs Discussion Both composite wraps (wet applied cloth) and composite sleeve (full-cure) system have a place in both piping and pipeline maintenance. Engineer mostly refer piping repair system to API 570 / ASME B31.3 and pipelines repair system into ASME B31.4 (for liquid) or B31.8 (for gas). Both of API and ASME has establish code for composite or nonmetallic repair for piping or pipelines. Other supporting code is ISO and PRCI (Pipeline Repair Council International). The composite wrap process is less suited to high-pressure repairs but has the advantage of being flexible and suitable for repairing irregular shapes. The mechanical properties of the full cure composite sleeve can be controlled and thus provide predictable performance and long-term durability. Composite Sleeve is the most appropriate composite repair for high-pressure pipelines. It is important to understand the design requirements of an effective composite repair and the installation variables that can influence long-term performance. The mechanical properties of the composite, its architecture and the method of installation can greatly affect the integrity and life of the repair. Each repair must be tested and validated independently. Defects such as internal and external corrosion, dents, and gouges are regularly found in both upstream and downstream sector. In the majority of cases these defects are minor and have no impact on the integrity and safety of the pipeline. But in some cases they can be significant and a repair is necessary.

Consequently, a reliable way of identifying defects that are critical, and need repair is required. The twin requirements of security of supply, and operating efficiency, mean that repairs should not be carried out if they are not required; hence, any method of identifying and assessing critical defects must be accurate and not excessively conservative. Furthermore, to ensure long term integrity, an appropriate repair must be selected. Selecting the appropriate repair technique is an important decision which requires an understanding of the risks and rewards associated with each composite repair alternative and material architecture selected. Safety, permanency and effectiveness are the primary drivers of this decision but cost can become an important issue. Composites, like Clock Spring, compete with older, more widely accepted welded repair techniques. These new repair options offer advantages over the more traditional repairs and are both more cost effective and are also the safest repair alternative. Nowaday, engineer have more repair alternative compared to the old times back at the 80’s. Composite repair technology is becoming more and more reliable and developed under tight code and standards. The ISO TS 24817 and ASME PCC-2 R&T article 4.1 is the main source for designing the best composite repair. Please notice that all wet wrap composite repairs have to be designed spesifically as per pipeline operating and design parameter which also consider the defect associated. The above case study application showed how we must carefully consider the code and



design and calculation involved with the repairs. This will also become an advantage in the future for the engineer as the design and calculation supplied by the composite vendor will be the reliable source if there is any failure at the repair system in the future. Conclusions Composite repairs may not be the right repair option every time but they are an important alternative that can be very effective in most repair cases and they are now increased and

utilized for piping and pipelines repairs in the up, mid and downstream sectors for maintaining asset integrity.

The above case study application showed how we must carefully consider the design and calculation involved with the composite repairs and choose the proper code and standard applied. Defects found in piping and pipeline systems at up, mid and downstream sector can be temporarily or permanently repaired safely, quickly and economically by using composite repair technology. Proper surface preparation is essential for the repair to perform as required. The repair of substrates using composite repair systems differs considerably from other repair techniques and the quality of the installation depends strongly on satisfactory craftsmanship. As such, only installers who have been trained and certified are permitted to install. BIOGRAPHY

Dimas Satya Lesmana is a Chemical Engineer which is currently working as Regional Manager for Asia Pacific region at Clock Spring Company L.P. USA and based in Indonesia. He was also a certified applicator and the only one certified composite repairs trainer for Clock Spring Company L.P. in the region.

References

API 570 - Piping Inspection Code: In-service Inspection, Repair, and Alteration of Piping Systems, Fourth Edition, American Petroleum Institute, 2016 Addendum 1, May 2017.

ASME B31.4 - Pipeline Transportation Systems

for Liquids and Slurries. Table 51.6.2.9-1 Acceptable Pipeline Repair Methods, 2016.

ASME B31.8 - Gas Transmission and

Distribution Piping Systems. Table 7.1-1 Acceptable Threat Prevention and Repair Methods, 2016.

ASME PCC2 - Repair of Pressure Equipment and

Piping - Article 4.1 Nonmetallic Composite Repair Systems for Piping and Pipework: High-Risk Applications, 2015.

Lesmana, D.S. - High Pressure Gas Transmission

Pipeline Repair using Clock Spring® Composite Sleeve in Indonesia, Petromin Pipeliner Magazine, Jul-Sept 2010 Edition.

Lesmana D.S. - Use of Clock Spring® as a

permanent means of pipeline repair. Rehabilitation of Pipelines Using Fiber-reinforced Polymer (FRP) Composites. Vistasp M. Karbhari, Elsevier Books Publishing USA, May 23, 2015.



ISO/TS 24817 - Petroleum, Petrochemical, and Natural Gas Industries: Composite Repairs for Pipework - Qualification and Design, Installation, Testing and Inspection, 2006.

Pipeline Research Council International (PRCI)

Updated Pipeline Repair Manual, Rev 6 – Defect Repair Using Composite Reinforcement Sleeves Table 1. Summary of repair options for various types of defects, 2006.

The Gas Research Institute. GRI-97/0413

Evaluation of a Composite System for Repair of Mechanical Damage in Gas Transmission Lines. Gas Research Institute, 1998.

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