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
  • F16L59/00—Thermal insulation in general
  • F16L59/14—Arrangements for the insulation of pipes or pipe systems
  • F16L59/16—Arrangements specially adapted to local requirements at flanges, junctions, valves or the like
  • F16L59/21—Arrangements specially adapted to local requirements at flanges, junctions, valves or the like adapted for expansion-compensation devices

Definitions

• This invention relates to axial compensators for pipe lines and insulation therefor.
• the invention provides a prefabricated insulated expansion element combined with an axial compensator having pipe ends directed in opposite directions and intended to be mounted in a culvert, characterized in that the expansion element comprises a pair of skid pipes, each arranged surrounding a pipe end and spaced therefrom, the spaces being filled with a flexible heat insulation material, the said skid pipes each being slidable in a common guide pipe, which surrounds the axial compensator and is spaced therefrom, each end of the guide pipe having a seal sliding on the skid pipe so that the said skid pipes are movable relative to the guide pipe, a protective pipe secured around the guide pipe and spaced therefrom, the space being filled with a heat insulation material.
• the prefabricated expansion elerrent is assembled on the axial compensator before they are mounted together in the pipe line, so avoiding the site work referred to above.
• Figure 1 is a longitudinal section of an expansion element and a side view (partly cut away) of an axial compensator in the expansion element
• Figure 2 is a longitudinal section through the right-hand portion of the expansion element of a modified design
• Figure 3 is a side view of the expansion element and of a prestressing means engaging therewith.
• the expansion element shown in Figure 1 comprises a pair of skid pipes
• skid pipes (1) and (2) having a central axis in common and arranged in spaced apart relationship.
• the remote ends of the skid pipes each have an end wall (3) and (4). Their ends facing each other are open and project into a guide pipe (5) which has sealing rings (6) and (7) and scraping edges (5') and (5") located around the respective skid pipe (1, 2) and sliding thereon.
• a protective pipe (8) is attached rigidly to the guide pipe, so that a closed intermediate space (9) is formed around the guide pipe over a substantial part of its length.
• the items (1 - 5) and (8) preferably are made of a stable plastics material.
• the guide pipe (5) extends round an axial compensator (10) spaced therefrom, and the skid pipes (1, 2) each surround a pipe end (13, 14) in spaced relationship thereto leaving spaces (11, 12) communicating wit the space inside the guide pipe.
• the pipe ends extend through central openings (15) and (16) in end walls (3, 4) of the skid pipes.
• the diameter of the said openings is equal to the outer diameter of the pipe ends (13, 14).
• Flexible seals (17) and (18) are attached adjacent the outside of the openings (15, 16) and about the pipe ends.
• the axial compensator (10) preferably is of the type described in U.K. Patent No. 1,531,792, which as appears from Figure 1 comprises two pipe connecting pieces (13' , 14') which are axially movable relative each other, their remote ends being connected to the pipe ends (13, 14).
• the ends of said connecting pieces facing toward each other are connected by means of a bellows (19), the ends of which are sealingly attached to the connecting pieces (13' , 14').
• the bellows (19) and the adjacent ends of the connecting pieces are surrounded by a guide sleeve (20) which is spaced from the guide pipe (5) to leave the space continuous with spaces (11, 12).
• the axial compensator (10) is provided with a stroke limiter (21), which prevents undesired change in length of the bellows (19), as described in U.K. Patent No. 1,531,792.
• the intermediate spaces (11, 12) and the communicating space at least up to the guide sleeve (20), are filled with flexible or compressible heat insulation material, for example mineral wool, and the intermediate space (9) also is filled with heat insulation material, which need not be flexible or compressible.
• a prestressing means is provided, which according to Figure 3 consists of two pipe clamp (22, 23) detachably attached on the pipe ends (13, 14). Two rods (24, 25) are attached to extend between the pipe clamps (22, 23).
• each rod is welded to the pipe clamp (22) while the other end is threaded and extends through a hole in the second pipe clamp (23) and supports a pair of lock nuts (26).
• the distance apart of the rods exceeds slightly the outer diameter of the protective pipe (8), and the length of the rods is slightly greater than the distance between the outer ends of the skid pipes (1, 2) so that they are located outside the expansion element as shown in Figure 3.
• the axial compensator (10) When the axial compensator (10) is to be mounted in the expansion element, the axial compensator (10) first is prestressed in known manner, which state is maintained by means of a fixture or the like engaging with the pipe ends (13, 14) so that the axial compensator is held prestressed, and extended. Its total length will then decrease when the axial compensator is subjected to compressing pressure due to an increase in temperature of the conduit in which it is situated. Thereafter the expansion element is secured around the axial compensator. The prestressing means (22 - 26) is attached to the pipe ends (13, 14) to replace the fixture, which is then removed, the prestressing means maintaining the pipe ends (13, 14) in their positions set relative to each other.
• the prestressing means (22 - 26) can alternatively be replaced by four pipe clamps (28 - 31 ) as indicated by dash-dotted lines in Figure 3. Two of the clamps (28, 29) are attached to the pipe ends (13, 14) and rest against the ends of the skid pipes (1, 2) while the other two of the clamps (30, 31) are attached to the skid pipes (1, 2) and rest against the ends of the guide pipe (5) , whereby the pipe ends (13, 14) are held prestressed by the guide pipe and skid ' pipes instead of by the aforesaid rods (24, 25).
• the prefabricated expansion element thus, .is provided with the prestressing means when the element is delivered to the place of installation.
• the expansion element thereafter is mounted, with the prestressing means remaining thereon, in a culvert, the pipe ends (13, 14) are connected by welding to the opposed pipe ends of a conduit in the culvert, whereafter the prestressing means is removed and the skid pipes (1, 2) are connected to the protective pipe of the culvert ⁇ preferably by means of a plastic sleeve (27) as indicated by dash-dotted lines in Figure 1, with insulation material inside the plastic sleeve.
• Figure 2 shows a modification, in which the ends of the guide pipe (5), of which only one end is shown, are provided with an additional seal (32) and scraping edge (33) thereon in order to improve the resistance to the penetration of water or other particles into the skid pipes.
• the central portion of the guide pipe in this case is formed by a sheet metal pipe secured by welding, as shown in Figure 2.
• the guide pipe for example, and the walls of the protective pipe connected thereto, may have another longitudinal section shape.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Thermal Insulation (AREA)
• Rigid Pipes And Flexible Pipes (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20339075

Family Applications (1)

Country Status (3)

Cited By (8)

Families Citing this family (1)

Citations (7)

• 1979
  • 1979-10-17 SE SE7908587A patent/SE438022B/sv unknown
• 1980
  • 1980-10-15 EP EP80901946A patent/EP0047242A1/en not_active Withdrawn
  • 1980-10-15 WO PCT/GB1980/000165 patent/WO1981001184A1/en active Application Filing

Patent Citations (7)

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