FAQ

General Composites

• How long have composites or FRPs 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.

• 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.

• 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

• 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

• 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.

• 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.

• 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.