Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L57/00—Protection of pipes or objects of similar shape against external or internal damage or wear
  • F16L57/04—Protection of pipes or objects of similar shape against external or internal damage or wear against fire or other external sources of extreme heat

Definitions

• the present application relates to a protection structure for explosion vulnerable and combustible, elongated members like hawsers, hoses, cables, pipes and similar.
• fibre hawsers constitute a much better solution than e.g. steel chains.
• One obvious reason is the specific weight of steel chains as compared to the specific weight of a correspondingly strong fibre hawser.
• steel in maritime surroundings is rather heavily exposed to corrosion.
• fibre hawsers may often be a favourable replacement.
• the invention is constituted by an articulated structure surrounding and protecting the hawser, while still providing full hawser ovability.
• the protecting structure in accordance with the invention may, depending on dimensions, provide protection against a hydrocarbon fire for two or four hours, and will thus fulfil the normally set requirements for safety regarding this type of fire in oil platforms and similar.
• a fire protected system is achieved which is equally strong as steel, but which weighs only one fifth of a steel system.
• the hawser together with its fire protection structure can be moved in all directions, and also a rotating movement can be imparted thereto.
• the protecting structure resists fire, does not corrode, is shock resistant, resistant to sea water and oil, is a low weight structure, is non-magnetic, electrically non ⁇ conducting and cannot cause sparking.
• the protecting structure can be used not only for fibre hawsers, but as indicated in the introduction, also as a protection around cables, pipes and hoses.
• the protecting structure consists of successive sections connected to each other by joints .in such a manner that the sections together form a movable, flexible and stretchable tube around the hawser to be protected.
• the material from which said sections are manufactured is in reality the so-called "Viking Fire Stop” material, i.e. a special rubber compound with excellent fire preventing and heat insulating characteristics.
• the material itself is not of paramount importance, since it is the section-wise construction which primarily constitutes the present invention.
• the single sections may display a substantially cylindrical exterior, but the expression "substantially cylindrical” shall in this context also comprise a conical shape or for instance an undulated outer contour.
• the assembly of many sections each of which deviating to a certain degree from a cylindrical shape, will nevertheless result in a substantially cylindrical shape when the hawser including its envelope is stretched out in a straight line.
• a double system i.e. the hawser to be protected runs in an inner bore and is surrounded by a first protecting structure, which itself is located in a bore in a second protecting structure. Both protecting structures utilize ball-and-socket joints, where the geometrical relations are adapted. Such a double protection system may prove very favourable.
• Fig. 5 shows the end pieces of the system, where the hawser is suspended in/strapped to outside constructions, and the end sections of the system are adapted around the suspension points.
• Fig. 6 shows typical dimensions of the system in connection with a parameter table
• fig. 7 shows how the tensile strength of a fibre hawser changes with temperature and time.
• the protecting structure consists of a number of joints, preferentially but not necessarily of the ball-and-socket type.
• a ball-and-socket connection provides very good possibilities for the joint to follow the hawser in all directions, and very small bend radii can be achieved.
• the ball-and-socket joint provides the axial movement necessary in order to follow the longitudinal extension of the hawser when it is exposed to a strain.
• the protecting system By constructing the joints connections as approximate spheres or balls, and snapping these into each other, the protecting system will maintain its radial strength at all times, and thereby render the system shock and explosion safe in all joint deflection positions.
• the joint deflection is adapted in such a manner that the system simultaneously works as a bend safety means for cables, pipes, hoses, wires, chains and similar. This is a substantial advantage, safeguarding against a bend overload for the object to be protected, which object always has a smallest allowed bend radius. This feature also increases the general system safety, and reduces the need for inspection.
• joint connections of the type mentioned provide a spring-like tensile connection, i.e. the articulate protection sleeve will pull itself together after a situation with a tensile load.
• joint connections are previsously known, also ball-and-socket connections, however an articulate protection system of the type mentioned above, is supposedly novel.
• the ability to achieve free movability, torsion, bending and extension and at the same time maintaining the radial stiffness and position (impact resistance) imply sufficient advantages to support a presumption that the system is a substantial improvement in relation to previously known products for fire and explosion protection.
• the Catcher system consists of 2 flexible layers of Viking Firestop, which cover a webbed Twaron fibre rope, which has two slings for connection to both riser and the frame. See drawing no. 26-372-303. On the end of the flexible layer there is a split end cover which fits into the flexible other layer of the Viking Firestop protection, and to the Chartec III fire protection cover which is specified used on the riser.
• the Viking Firestop layer consists of a number of joints, which are fitted together with a ball-and- socket joint connection, which gives sufficient movement for the joints to follow the rope/catcher in all directions and specified bending radiuses ( in. 1 ) .
• the ball and socket joint also gives the necessary axial movement to follow the elongation on the rope which takes place.
• the whole catcher cover is locked between the two connection slings on both sides of the rope (see drawing) , and will therefore always be kept together and in a right and safe position.
• the end protection consists of a split cover which is kept together with clamping rings, and has to be adapted to the Chartec III configuration.
• the dimension of the Chartec III protection cover is not shown in the drawing, therefore this end cover has to be adapted directly on the Chartec III body.
• the Twaron webbed fibre rope is a well tested rope offshore, and gives many advantages compared to steel products.
• the rope is delivered with Lloyds or Veritas certificate and with all relevant data sheets. See enclosed data sheet and pamphlet.
• advantages in item 3.1.4 for the use of rope, there are other features:
• a Twaron webbed fibre rope has a relatively slow percentage loss of strength with influence of high termperature, ses enclosed diagram for 340° from 4 to 5 hours.
• a Twaron webbed fibre rope will also, because of its ela ⁇ tical property, have a suitable and important ability to withstand impact forces, for pulse

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Earth Drilling (AREA)
• Protection Of Pipes Against Damage, Friction, And Corrosion (AREA)
• Laying Of Electric Cables Or Lines Outside (AREA)
• Details Of Indoor Wiring (AREA)

Priority Applications (1)

Applications Claiming Priority (1)

Publications (1)

Family

ID=19894130

Family Applications (1)

Country Status (3)

Cited By (42)

Citations (1)

• 1991
  • 1991-05-06 NO NO911773A patent/NO174683C/no unknown
• 1992
  • 1992-06-18 WO PCT/NO1992/000110 patent/WO1993025839A1/en not_active Ceased
  • 1992-06-18 AU AU20218/92A patent/AU2021892A/en not_active Abandoned

Patent Citations (1)

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