FAQs

General Composites FAQs

PRT Aquawrap® / Moisture Cured Urethane (MCU) / Pre-Impregnated (Pre-Preg) Composite FAQs

PRT PowerSleeve® / Field-Wetted / Wet-Layup Composite FAQs

PRT Project Design FAQs

How long have composites been in use and what are some of the advantages?

Composite materials, also known as FRPs (Fiber Reinforced Polymers), have been in use for decades. They have been developed extensively for use in aviation and aerospace applications where high strength and low weight are a necessity. Over time, stronger fabrics (substrates) combined with higher performance resins (matrices) have evolved to make some composite materials stronger than steel. In addition to being strong and lightweight, composites can conform to any shape, are chemical and corrosion resistant and can operate over a wide temperature range. These qualities combine to make composites desirable for many applications.

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Why are composites more widely used in recent years?

In addition to the strength, weight and conformability advantages, composites are more widely used now because they have been field proven and are cost effective.

As a repair or reinforcement, composites can cost much less to install when compared to traditional welded sleeve or replacement methods. In piping or infrastructure repairs, costs associated with downtime, fabrication and installation can be tremendous. In most cases composites can be installed with no downtime, no hot work, less manpower and can be designed as a permanent repair.

Introduction of standardized testing and regulatory compliance guidelines have also made the composite repairs a more viable alternative. Manufacturers that perform testing in accordance to these exacting standards can provide more accurate data used to engineer effective composite repairs.

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What types of industries use composites?

Composite uses can be found in numerous industries. The following are some that commonly use composite materials.

  • Chemical plants
  • Pipeline companies
  • Food processing plants
  • Port authorities
  • Marine industry
  • Public utilities
  • Military
  • Pulp/paper plants
  • Nuclear power plants
  • Refineries
  • Offshore facilities
  • Water treatment plants

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What regulatory compliance standards are PRT composites in compliance with or validated to?

  • ASME B31G
  • ASME B31.1
  • ASME B31.3
  • ASME B31.4
  • ASME B31.8
  • DOT 49 CFR Parts 192 and 195
  • ASME PCC-2
  • ISO/TS 24817
  • NSF/ANSI Standard 61

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Are the PRT composite materials difficult to use?

Not at all. In fact, PRT composites are designed to be very user friendly. The PRT Aquawrap® material is pre-impregnated with the proper amount of resin at the factory. The PRT PowerSleeve® field-wetted material comes in diameter specific kits that have the pre-measured amounts of resin and include all the materials you need for a successful installation. Even the epoxy sticks and the epoxy basecoat resins are factory measured, easy to mix and easy to apply.

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Can my personnel be trained and certified to perform PRT composite installations?

Yes. The training and certification of your personnel can be arranged at our office or yours. As user friendly as the PRT composite products are, we believe that proper training is the most important part of the process. The training demonstrates proper surface preparation, hands-on application techniques and an overall understanding of how composite repair systems work. These must all be in place to assure the highest quality installations and successful projects.

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I’ve seen composite repair systems referred to by many different names. What are the categories and differences?

There are three categories of composite repair systems:

  1. Pre-Impregnated (Pre-Preg) Moisture Cured Urethane (MCU) system
  2. Field-Wetted (Wet Layup) system
  3. Pre-Formed (Pre-Cured) system

The first type of composite repair system is the Pre-Preg / MCU. This type is a roll of fiberglass or carbon fiber fabric substrate that is pre-impregnated during manufacturing with the appropriate amount of resin and individually sealed in airtight bags. These require no measuring or mixing and are activated by simply adding water. They can conform to complex shapes such as tees, reducers, elbows and manifolds. They are capable of continuous, uniform installations regardless of the length of the repair area. Pre-Preg / MCU composite systems such as PRT Aquawrap® offer outstanding structural reinforcement, fast curing times, ease of application and can be installed underwater.

The second type is the Field-Wetted or Wet-Layup composite repair system. These also consist of a fiberglass or carbon fiber fabric substrate. The resin, however, is an epoxy that is mixed and applied to the substrate on-site. While Field-Wetted composites take longer to prepare and apply, they have advantages in certain applications. They are preferable for highly technical, curved and complex surfaces. The pieces can be measured and cut to fit before being wetted and can also be used for flat surface applications. The 100% solids epoxy resin cures to form an impermeable barrier. They are also capable of continuous, uniform installations regardless of the length of the repair area. Field-Wetted composite systems such as Kevlar® reinforced PRT PowerSleeve® offer exceptional strength, adhesion, conformability and chemical resistance.

The third type is the Pre-Formed or Pre-Cured composite repair system. The substrate and resin are formed and cured in rigid layers or coils during the manufacturing process and produced for repairs on specific pipe diameters. During installation, an adhesive component is applied between the layers of the coil as it is wrapped around the pipe. For repairs longer than the width of one coil, they are placed side by side in segments. The rigid Pre-Formed composites are not practical for use on tees, reducers or elbows. Applications are often limited to shorter, straight run repairs with generous working access. Because of the adaptability and many advantages of the PRT Aquawrap® and PRT PowerSleeve® composite repair systems, we do not offer a Pre-Formed composite system.

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PRT Aquawrap® FAQs

How long does PRT Aquawrap® take to cure?

Once the airtight bag is opened, the PRT Aquawrap® has a total working time of approximately 60 minutes at 77F (25C). Even the slight moisture in the air will begin the curing process, so it is important to have the surface prepared and work area ready before opening. When the installation begins, it is necessary to apply water to fully activate the material. The cure time is approximately 30 minutes after water is applied. Curing will occur more slowly at lower temperatures and faster at higher temperatures. Full cure properties for PRT Aquawrap® are at 24 hours.

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What sizes does the PRT Aquawrap® come in?

The standard PRT Aquawrap® comes in widths of 2,3,4,6,10 and 12 inches. The material ranges in length from 5 feet to 30 feet in the smaller width materials and lengths up to 150 feet in the wider materials. Custom sizes can be accommodated for specific needs on large projects.

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What materials can PRT Aquawrap® be installed on and how do the surfaces need to be prepared?

The PRT Aquawrap® can be installed on almost any material with very few exceptions. The ideal surface preparation is a NACE No. 2 / SSPC-SP10, near-white metal, blast cleaning. This 2.5 - 4 mil (63 - 101 micron) anchor profile is the most desirable surface preparation. If media blasting could further damage the defect being repaired, it is recommended to isolate that area and proceed with ideal preparation surrounding the defect. This will provide good landing areas for the composite repair to adhere and encapsulate the defect. If the ideal surface preparation is not allowed due to permits or overall pipe condition, it must be best possible. Better surface preparation equals a higher quality installation. The following are some of the materials on which PRT Aquawrap® can be used:

  • Aluminum
  • GRE
  • Carbon steel
  • PVC
  • Cast iron
  • Polyethylene
  • Concrete
  • Polypropylene
  • Copper
  • Stainless steel
  • Fiberglass
  • Titanium

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What are some of the strength properties of PRT Aquawrap®?

The PRT Aquawrap® is available with several types of substrates or fabrics for different applications. As a brief summary, these have mechanical properties up to 123,000 psi Tensile Strength, 28,500 psi Compressive Strength, 3,465 psi Interlaminar Shear and 1,000 psi Adhesion (Lap Shear). These values have been determined by ASTM testing procedures performed and certified by independent testing laboratories. The PRT Aquawrap® is simply the most thoroughly tested and proven Pre-Preg composite available.

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What types of repairs is PRT Aquawrap® best suited for?

The PRT Aquawrap is best suited for structural reinforcement applications. It can replace hoop and axial strength to piping restoring its original capabilities. It is effectively used to reinforce infrastructure such as piers and supports for concrete remediation projects. It is also remains the product of choice when installing in wet or underwater conditions.

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PRT PowerSleeve® FAQs

How long does PRT PowerSleeve® take to cure?

The 100% solids epoxy resin for the PRT PowerSleeve is a two component mixture. Once mixed, the cure time (dry to the touch) is approximately 30 minutes at 77F (25C). It has a very high percentage of its fully cured properties at 8 hours and is fully cured at 24 hours.

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What sizes does the PRT PowerSleeve® come in?

The PRT PowerSleeve kits come in pipe specific sizes from 6 inch diameter all the way through 108 inch diameter applications. Each kit comes complete with installation supplies and the appropriate amount of materials to apply 4 layers over a 12 inch wide repair. In addition to the pipe specific sizes, custom bulk kit quantities can be supplied for large projects.

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What materials can PRT PowerSleeve® be installed on and how do they need to be prepared?

Like the Pre-Preg material, the PRT PowerSleeve can be successfully installed on almost any material. The ideal surface preparation is a NACE No. 2 / SSPC-SP10, near-white metal, blast cleaning. This 2.5 - 4 mil (63 - 101 micron) anchor profile is the most desirable surface preparation. If media blasting could further damage the defect being repaired, it is recommended to isolate that area and proceed with ideal preparation surrounding the defect. This will provide good landing areas for the composite repair to adhere and encapsulate the defect. If the ideal surface preparation is not allowed due to permits or overall pipe condition, it must be best possible. Better surface preparation equals a higher quality installation. The following are some of the materials on which PRT PoweSleeve® can be used:

  • Aluminum
  • GRE
  • Carbon steel
  • PVC
  • Cast iron
  • Polyethylene
  • Concrete
  • Polypropylene
  • Copper
  • Stainless steel
  • Fiberglass
  • Titanium

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What are some of the strength properties of PRT PowerSleeve®?

The PRT PowerSleeve® substrate is a hybrid fabric of high grade E-glass and Kevlar® reinforcement fibers. When combined with the 100% solids epoxy resin, it forms a high strength, high adhesion, impermeable barrier. A brief summary of the mechanical properties are 75,400 psi Tensile Strength, 29,400 psi Compressive Strength and 4,580 psi Interlaminar Shear. These values have been determined by ASTM testing procedures performed and certified by independent testing laboratories.

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What types of repairs is PRT PowerSleeve® best suited for?

The PRT PowerSleeve® has several key applications. First, it is well suited for technical, complex and curved surfaces that would be difficult to wrap around with a Pre-Preg material. Because of the high level of adhesion, it is also very effective for flat surface repairs. Another advantage is the impermeability of the 100% solids epoxy resin matrix. This makes it the product of choice for encapsulations and containment repairs of future through wall internal defects.

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PRT Project Design FAQs

How long will PRT composite repairs last?

This depends upon the specific design requirements of the client. By making adjustments to the number of layers and combination of materials used, the PRT composite repairs can easily be designed to last in excess of 20 years.

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Up to what temperatures and pressures can PRT composites be used?

The PRT Aquawrap® can be used in applications with a sustained temperature up to 288F (142C). With the use of our high temperature resin, the PRT PowerSleeve® material can be used with a sustained temperature of 525F (273C).

With regard to pressures, the PRT composite system can be designed for applications in excess of 150 Bar (2200 psi) and has been tested in excess of 300 Bar (4400 psi).

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Can PRT composites be applied over an active leak?

No. If the pipe or vessel has an active leak, it must temporarily be shut down. The defect can then be repaired using the appropriate PRT composite system. Because of the rapid installation and cure times the line can be brought back into service very quickly.

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Can solutions be designed for internal corrosion/erosion situations?

Absolutely. We frequently design solutions for internal defects. These must address both product and pressure containment in anticipation of future through wall conditions. This requires a proper assessment of the compatibility of the composite material to be used and the product contained in the line. The impermeability and high adhesion level of our 100% solids epoxy resin creates the containment barrier. Depending upon the calculations, additional layers of either the PRT PowerSleeve® or the PRT Aquawrap® would provide the needed pressure reinforcement to complete the repair.

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How does my company proceed with a composite installation once we have identified a potential repair?

When a potential repair is identified, PRT works directly with you to determine the project details, project design, material requirements and installation procedures. Depending upon the size and complexity of the installation we can also provide on-site supervision to oversee the project through completion.

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What information needs to be provided to PRT to design an appropriate repair?

When we are working with you to design a repair, we will gather information on a project assessment form. Specific details will include pipe diameter, material grade, design pressure, design temperature, wall thickness, maximum and minimum operating pressures and temperatures and size and type of anomalies. Applying this data, we use our Design Calculation software to determine the type of material and number of layers needed to safely restore the integrity of the system. Other factors such as internal erosion/corrosion, type of product contained in the system and design life of the repair will affect the final design parameters.

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What types of composite repair solutions does PRT design?

We design repair solutions that fall into two broad categories which are structural enhancement and corrosion mitigation. Repair solutions for most projects address aspects of both categories to restore strength and to halt or encapsulate future corrosion. The following are some specific types of repairs that can be performed using PRT composites.

  • Abrasion/wear resistance
  • Full hoop/axial strength replacement
  • Bend repairs
  • Isolation/Insulation
  • Corrosion mitigation
  • Leak repair (special applications)
  • Cracks
  • Manufacturing/fabrication defects
  • Dents/gouges
  • Structural reinforcement
  • Encapsulation
  • Underwater repair capability
  • Erosion
  • Weld joint/HAZ reinforcement

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What other types of products does PRT offer?

The remaining segment of the PRT product line is epoxy coatings and adhesives. These epoxies are industrial grade, extreme service products that we use as an integral part our composite wrapping systems.

Since our specialty is knowing what products to use on a given repair design, we have epoxies with differing capabilities. We have specialized formulations for high temperatures, high chemical resistance, underwater applications and even a system that can be applied in the presence of hydrocarbons. In addition, the cure times for our epoxies can be adjusted from several hours to as little as 5 minutes to suit the application.

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  • Hydrocarbons? No Problem

    PRT now has a 100% solids epoxy product that adheres in the presence of hydrocarbons such as diesel or gasoline. It actually displaces them from the wetted surface to form a permanent bond.
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  • Why Composites?

    There are more great reasons than ever to consider composite repair systems for your piping and infrastructure remediation needs. No downtime and no hot work are at the top of the list.
    Continue Reading >>

What Types of Repairs?

Modern composite repair systems are extremely versatile and adaptable. They can be customized for specific tasks and have impressive capabilities that make them attractive options to traditional repair or replacement methods.
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ASME PCC-2 Spool Test Summary

Testing was recently performed on our PowerSleeve® composite system. The 80% wall loss repair was pressurized to 8200 psi (565 bar). It performed as calculated and was a complete success.
Continue reading »

Gallery

Bridge Column Before Completed 20 Inch Clamp Enc 36 x 24 Inch Double Eccentric Reducing Tee Bridge Column During