PDF Publication Title:
Text from PDF Page: 009
J. Mar. Sci. Eng. 2020, 8, 26 9 of 28 Fiberspar Line PipeTM and composite reinforced linear tube (CRLP) represent two relatively new types of composite tubes used in the transport of natural gas. CRLP consists of steel tubes coated or wrapped in a shell of continuous composite material which adds strength and protection to the steel [2]. Fiberspar Line PipeTM is a glass fiber reinforced epoxy laminated tube. This tube is currently made in diameters from 1-1/4 to 4 inches and pressure values ranging from 750 to 3000 psi (approximately from 50 to 200 bar) [22,23]. Steel pipes used to transport oil and gas are highly sensitive to corrosion and subsequent failure. Hydroxides and chloride ions in submerged conditions and in seawater environment accelerate processes leading to metal leaks, cracks, and breakage. Damage evolution is then accentuated by the considerable pressure acting on this kind of component. Being corrosion and loss of metals the main cause for damage in offshore pipes, their repairing is of paramount relevance to the oil and gas industry. As a consequence, intensive study has been devoted to this topic during the past decades all over the world. Conventional repairing techniques for a damaged pipe consist of removing the damaged portion (or the entire pipe) and replacing it with a new one. As an alternative, the damaged region is covered using a layer of welded steel. In other words, external steel sleeves are welded or fixed to the outer surface of the tubes. Welding steel is a cumbersome process especially when it is performed underground or underwater. So, a significant effort has been directed toward the identification of effective and safe repair solutions. The costs and technical issues for repairing and maintenance strategies increase considerably with the operating pressure and the position of the tube damage. Therefore, relatively lighter and more easily applicable alternative materials are desirable. Reinforced fiber composites have been proposed as an optimal alternative solution for the repairing of these tubular structures [21,24], due to their lightness, high strength and stiffness, good corrosion resistance and excellent properties when subjected to fatigue loading conditions. Currently, composite materials commonly adopted for such interventions include E-glass, aramid or carbon fiber as reinforcement and thermosetting resin (polyesters, polyurethanes, phenolics, vinyl esters or epoxies) as matrix material. Depending on the specific pipe repairing method, the aim is to prevent the further extension of the corroded zone, restore the load-bearing capacity of the damaged pipe, avoid fluid leakage from the damaged area, or a combination of them [24]. Two methods, based on a wet layup or on the usage of pre-cured layers, are generally adopted to repair faulty pipes. Wet layup consists of repairing the damaged area using fibers that are impregnated directly in situ. Special epoxy resins, capable of underwater polymerization, are used as matrices. An alternative method involves the application of epoxy-based resin systems and carbon fibers altogether with a flexible shell. Carbon fibers are circumferentially oriented providing enhanced strengthening to the support steel tube if compared to E-glass reinforcement, assuming the thickness of composite shell as fixed. The pre-cured layer technique consists of using pre-impregnated composites avoiding issues attributable to an underwater resin cure in a restricted and not easily accessible space. This method is mainly applied in case of damage localized on straight pipe sections [24,25]. The aforementioned methods can be combined or hybridized in order to (at least partially) solve the drawbacks affecting them singularly. An example is the use of half-shells of carbon to be impregnated in situ rather than using the classic scheme of overlapping sheets of fiber layer by layer. To date, due to the practical challenges in the application of FRP repairing material, metal sleeves still represent the most adopted solution. The application of FRPs in the offshore sector has been also considered for the production of a variety of primary and secondary structures. Primary or critical structures installed on floating plants include risers and tendons. Secondary structures on floating platforms that can be manufactured from composites include helicopter bridges, piping systems, dwellings, walkways, stairs. Risers and tendons are flexible systems connecting the floating platform to the subsea structure. Such platforms, in case of significant seabed depth, are generally built converting disused oil tankers, due to the reduced realization cost and the possibility to store crude oil [26–28].PDF Image | Marine Application of Fiber Reinforced Composites
PDF Search Title:
Marine Application of Fiber Reinforced CompositesOriginal File Name Searched:
jmse-08-00026.pdfDIY PDF Search: Google It | Yahoo | Bing
Development of a solar powered Electric Ship The Electricship website originally started off as a project to develop a comprehensive renewable, affordable, modular electric ship... More Info
Modular Boat Hull Composite The case for a unsinkable, modular composite hybrid boat hull... More Info
MS Burgenstock Hybrid Electric Catamaran Lake Lucerne Unique shuttle servicing Lucerne to the Burgenstock Resort... More Info
Ground Power Unit GPU Powered by Lithium Ion Batteries The goal of the Ground Power Unit is to provide a readily accessible, modular, ready-to-power solution for remote power... More Info
CONTACT TEL: 608-238-6001 Email: greg@electricship.com (Standard Web Page)