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FRP Vessels - A Supplier's Perspective
Abstract
In the world of chemical processing, many customers are faced with a dilemma when choosing the proper material for equipment used to store or process their corrosive materials, as well as how well the equipment will stand up to its external environment. For over 50 years, FRP, or fiberglass reinforced plastic, has been used as an excellent choice of material for corrosion resistant equipment in many industries.
FRP composite materials have been used with much success in multiple industries for storage and processing of acid and acid chlorides at elevated temperatures. In services where large amounts of SO2 and SO3 are being released, many FRP composites have proven their reliability when used in equipment designed to scrub sulfur oxides and convert them to sulfuric acid. Naturally, these processes create a very harsh environment, especially when hot or wet flue gases are introduced with high concentrations of the aforementioned sulfur oxides. As with acids, FRP is also an excellent choice for environments such as MgOH, NaCL, NaOCL, FeCl3 and similar chemicals used in the wastewater treatment industry and ClO2 bleach pulp in the pulp and paper industry.
When viewing composites as an engineering material, FRP remains superior in corrosive environments, not only because of its resistance to corrosion attack, but also its excellent strength to weight ratio. For example, an FRP laminate can be 1/6th to 1/3rd the weight of steel, while providing up to a 32,000 PSI ultimate tensile strength in contact molded laminates and up to 60,000 PSI ultimate hoop tensile strength in filament wound applications. In addition, FRP material is naturally non-conductive and does not require cathodic protection or corrosion inhibitors like many
other materials. Where these are required, operational and maintenance costs are often increased.
While FRP is not an entirely maintenance free material, it will often times significantly reduce maintenance costs when compared to other materials. FRP does not rust and provides excellent protection from exterior elements. With proper inspection and preventive maintenance, along with the proper operational controls, FRP equipment will far exceed the lifespan of many other materials. Additionally, due to the inclusion of the corrosion barrier in its construction, FRP does not usually require additional coatings or linings that will fail over time.
Determining Suitability
How do you know if an FRP composite laminate is right for your application? There are many factors that each need to be carefully considered before choosing FRP as a material of construction. Most of which relate directly to the process conditions and operational/design parameters. In order for any FRP laminate to provide the desired performance and maximum service life, the type of resin used in the manufacture of the laminate must be compatible with the chemical/s being processed or stored. While temperature can certainly be a limiting factor, with the use of alternative dual laminates and high temperature resins such as Furan, many times these limitations can be overcome. Additionally, dual laminate construction now allows FRP to be used in ultra-high acid and caustic concentration applications where previously it was not suitable. Along with our industry-leading material suppliers, we will help you determine the best solution for your particular application.
Choosing a Supplier
If you have concluded that FRP may provide your corrosion solution, the next step is to wade through the sea of suppliers that claim to offer these materials. This can be a daunting task for the inexperienced buyer or engineer, as not all suppliers are created equal. Choosing a supplier can be done in a variety of ways, but the most important step is to ensure the supplier you choose has experience in your application, as well as the support from materials experts to properly design a laminate
Winning Together
The Strand Composites team remains committed to helping your company find the right solution to store or process your commodity, while providing you with the safest, most cost-effective and most maintenance free equipment possible. From your very first encounter with one of our sales team members to the time your product is delivered, everyone is focused on your needs. Once you have our products in place, that level of commitment does not end. Strand offers round the clock field service, industry leading engineers, inspectors and FRP experts that are all just a call away.
Benefits of Choosing an ASME Accredited Fabricator
When choosing an FRP supplier with ASME accreditation, you will receive the following:
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Design by a professional engineer
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Manufacturing in accordance with written procedures by certified craftsmen
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Manufacturing with certified materials,
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Detailed quality control documentation
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Final inspection report
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Designated inspectors report
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Fabricator’s data report certifying compliance, allowing full traceability of all materials and full transparency during the fabrication process
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Third party verification, by ASME, of fabricator’s strict adherence to all codes and standards
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Codes and standards enforced by ASME and law
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to meet your expectations and provide the longest service life possible.
Suppliers can also be sorted by their quality standards. ASME offers accreditations to shops that can properly execute their high standards and maintain that environment on a day-to-day basis. ASME RTP-1 is considered by many to be the best available control technology for FRP design, fabrication and testing. This covers designs for tanks and process vessels from +/-15 psig design pressure. When vessels require additional design pressure, ASME offers Section X Class II authorizations to cover vessels from full vacuum to +250 psig design pressure.
Strand Composites possesses both aforementioned ASME capabilities and was the first company to possess both accreditations. We maintain a vigorous quality control program that is unparalleled in the industry and maintain close relations with industry experts to help you choose the right materials. No equipment is too small and we can provide vessels and equipment up to 57’ in diameter using our patented ring-oblation process, with almost endless possibilities on height.
Field-Erected Vessels and Equipment
Diameter is not an issue for Strand Composites. In 1978, we patented our custom ring-oblation process. This process allows Strand to fabricate all major components of a large diameter FRP vessel in our shop and deliver them to the project site in easily shippable dimensions. Once on site, the components are removed from the shipping crates and erected in a fraction of the time it takes to build a traditional alloy vessel. All work is performed very close to ground level and requires no hot work. This, of course, drastically reduces safety concerns. As with shop vessels, field erected vessels are built to the same high quality standard and can be stamped as ASME RTP-1 certified.