FR2729210A1 - Pipe insulation element - Google Patents

Abstract

Pipe-insulating assembly is formed by insulating elements (1) surrounding a pipe, each having joint surfaces with opt., interengaging male and female assembly parts (7, 8) which are homologous extending along their lengths. Each element has an external covering (2) of metal or plastic sheet curved in the shape of a channel and terminating in flanged edges (4, 5) and corresp. at least to a portion of the periphery of the structure to be produced, the channel receiving an insulating rigid foam (3) so as to leave a depression (6) shaped and dimensioned like the pipe to be insulated. The joint surface is provided with a layer of flexible foam (4) and the closing of an insulating element on itself or the joining of insulating elements to one another is effected face to face by the layers of flexible foam. Also claimed is a process for mfg. the pipe-insulating element by taking a sheet (62) as wide as the periphery of the pipe insulation structure to be produced and folding it partially in a template (60, 61) corresp. to a semi-circle. A diametral partition (65) is placed inside the channel thus produced, the side edges of the sheet are closed to form a complete casing and the curvature is locked by means of complementary templates (63, 64), the bent edges (70, 71) of the sheet forming the wall meeting against the partition (66) which carries a tube (66) in its central position forming a moulding core constituting the depression of the pipe to be insulated. The foam is injected into the mould thus formed after covering the partition and the pipe with a sheet of foam which subsequently becomes integral with the injected foam and after placing a sheet (21) longitudinally forming a hinge enabling the two halves of the insulating element to be opened, an adhesive strip (27) on the internal surface of the sheet not being adhesive with respect to the foam.

Description

t Pipe insulation assembly formed of elements and method of manufacturing such elements
The present invention relates to a pipe insulation assembly formed of insulating elements and to a method for manufacturing such elements.

 There are currently various techniques for insulating pipes in which a hot or cold fluid circulates to be maintained at a certain temperature.

 These different insulation techniques consisting either in winding around the pipe a strip loaded with an insulator, or in making a kind of formwork generally formed from two sheet metal half-shells, each corresponding to a half-cylinder of circular section, then to inject in the meantime the foam are relatively delicate and long operations.

 The present invention proposes to considerably simplify the insulation techniques by creating insulating elements, manufactured in the factory and the mounting of which on the pipes to be insulated is particularly simple, rapid and effective and which is also impervious to runoff fluids which can fall on the insulation.

To this end, the invention is characterized in that - each insulation element comprises an outer wall
curved in the shape of a chute, consisting of a sheet
relatively rigid ending with folded edges
and corresponding at least to a fraction of the periphery
of the insulation to be produced, the trough receiving a portion
insulating leaving a shape and dimen reservation
sions corresponding to those of the pipe to be insulated, this
insulating part forming the limited junction surfaces
by the folded edges, - the closing of an insulation element on itself or
the assembly of insulation elements to each other is
going side by side.

 As the characteristics of the insulation assembly are predefined as a function of the diameter of the tube, the temperature and the efficiency of the insulation to be produced and as we know the layout of the piping to be insulated, it is easy to prefabricate insulation elements which will simply be assembled on site around the pipes.

 This makes it possible to considerably increase the efficiency of the insulation work to go from a custom stage to an industrial stage.

 The different features of a pipe can be taken into account by an on-site adaptation, for example for tappings and other accessories that can equip a pipe.

 Particularly advantageously, the outer wall is a sheet of sheet metal or plastic.

 According to another advantageous characteristic, the edges of the sheet are folded in the junction plane.

 In all cases, whether the insulating element corresponds to half of the insulation or to a different fraction, it is bordered by two joining surfaces, against which the other element or elements will be joined and the folded edges of the sheet forming the wall are each located in the junction plane.

 According to another characteristic, the junction planes comprise male / female assembly parts, homologous, extending over the entire length of an insulation element.

 These assembly parts facilitate the joining of the elements to complete the surround of a pipe while creating a baffle.

 The longitudinal meeting is advantageously carried out thanks to the ends of each element which are provided, on one side, with a groove and on the other side with a domed crown, to allow fitting.

 According to another advantageous characteristic, the insulating element consists of a curved sheet corresponding substantially to the periphery of the insulating element to be produced, and the longitudinal edges of which are curved at right angles, this sheet carrying two parts of corresponding foam. each has one half of all the insulation, bordered on one side by the respective folded edge of the wall, the middle of this wall constituting a longitudinal articulation making it possible to open at least partially the two halves to surround a pipe.

 It is also possible to give the outer wall the shape of a toroidal trough receiving the insulation so as to produce an insulating element for a pipe bend.

The invention also relates to a method of manufacturing an insulating element, this method being characterized in that - a sheet of width corresponding to the length is taken
peripheral heat of the insulation element to be produced and
we fold, at right angles, the longitudinal edges of this
sheet, - place the sheet in a bending template for
sea a chute corresponding to at least a fraction of
the periphery of the insulating element to be produced, - the cover is covered with a cover carrying a horn tube
corresponding to the dimensions and position of the pipe which
must receive the insulation, - foam is injected into the mold thus formed to
the foam sticks to the inside of the sheet
curved and blocks its bending.

 According to another characteristic, we take a sheet of width corresponding to the periphery of the insulation of the pipe to be produced, we fold this sheet, partially in a template corresponding to a semicircle, then we place inside the chute thus produced with the sheet, a diametrical partition, the lateral edges of the sheet are closed to form a complete envelope and the bending thus produced is blocked using complementary templates, the curved edges of the sheet forming the wall joining against the partition , the partition carrying a tube in the central position to form the molding core constituting the reservation of the pipe to be insulated, then the foam is injected into the mold thus formed.

 It is particularly interesting that, in the case of a single insulating element surrounding the pipe, the hinge, formed in the wall, is very free and for this, according to the method, in the longitudinal zone of the sheet, forming the hinge allowing open the two halves of the insulation element, place an adhesive strip on the inside of the sheet, the outside surface of this strip not being adhesive for the foam of the insulation element, then the foam is injected so as to allow the foam to take off from the inner surface of the sheet at the area forming the joint.

To make an insulating element to wrap an elbow: - we make a piece in the shape of a torus cut according to
diametral plane, - a cover fitted with sub-flanges is put in place
radial sion and an O-ring for the reservation of the
pipe, - we introduce the foam, and we cut the whole after
lifting of the cover along shelves and according to
angular arcs desired for the elbows.

 In general, the method according to the invention, whether it is to produce straight insulating elements, in one or more parts to surround a pipe segment or whether it is insulating elements to surround a bend, is implemented in a particularly simple and effective manner, allowing very advanced standardization of manufacturing, according to the different diameters of pipes or insulation to be produced.

The present invention will be described below in more detail with the aid of the accompanying drawings in which
FIG. 1 is a schematic perspective view of a first embodiment of an insulating element according to the invention,
FIG. 2 is a sectional view showing the assembly of two insulating elements according to FIG. 1,
FIG. 3 is a sectional view showing the assembly of a variant of insulating elements according to the invention,
FIG. 4 is a sectional view of another variant of insulating elements according to the invention,
FIGS. 5A, 5B, 5C show three stages of manufacturing and shaping of a sheet constituting the external wall of an insulating element according to FIG. 1,
FIG. 6 is a schematic perspective view of a template for the manufacture of an insulating element according to FIG. 1,
FIG. 7 is a schematic view of a cover for the jig of FIG. 6,
FIG. 8 is a sectional view of an assembly of several templates and of a partition used to manufacture an insulating element according to FIG. 4,
FIG. 9 is a partial view of a partition of adjustable diameter for use in a mold and jig according to FIG. 8,
FIG. 10 is a schematic view of an end flange of an insulating element according to the invention,
- Figure 11 shows a mold part.

FIG. 12A is a half-section showing the placing of two insulation elements end to end before they are joined,
FIG. 12B shows in half-section the union of the two insulation elements according to FIG. 12A,
FIG. 13 is a perspective view of a variant of insulation elements according to the invention,
FIG. 14 is a detailed view of the junction of two insulation elements according to FIG. 1 on a pipe,
FIG. 15 is a perspective view of an external wall used to simultaneously manufacture four insulation elements for 900 bends of insulation installations,
FIG. 16 is a perspective view of the template which is placed inside the part forming the external wall according to FIG. 15.

 In general, the invention relates to a pipe insulation assembly, formed of insulation elements placed on a pipe or a set of pipes traversed by a hot or cold fluid.

 According to the example of FIG. 1, this insulation element 1, which corresponds for example to half of the periphery of the complete insulation assembly, is in the form of a shell, the outer wall 2 of which is consisting of a sheet, for example of sheet metal or plastic. This sheet surrounds a foam part 3.

The edges 4, 5 of the sheet 2 are folded at right angles they are used to assemble two elements (1) to each other or to close an insulation element on itself as will be seen later; this assembly is done in the longitudinal direction, that is to say the direction of the pipe.

 The edges 4, 5 lie in the junction plane. The junction plane is formed by the flat face of the element which, in the position shown, is the face turned upwards.

 In the junction plane, the foam part 3 appears with a longitudinal reservation 6 of shape adapted to that of the pipe for which this insulation element 1 is intended; it is for example a form of semi-cylinder of circular section. The face of the junction plane also includes male / female assembly parts 7, 8 in relief and recessed with respect to the junction plane and having identical sections, in homologous positions with respect to the axis of the reservation 6 of the pipe.

These assembly parts 7, 8 extend over the entire length of the insulation element 1.

 According to the invention, such elements 1 are assembled around the pipe to be insulated so that the male / female assembly parts 7, 8 overlap and form baffles in the junction plane. These baffles improve sealing and insulation and give the assembly some blockage. At the time of assembly, the folded edges 4, 5 of the outer wall 2 come to bear against one another under the effect of assembly members not shown, such as for example pliers.

 In this example, the edges 4, 5 of the sheet constituting the outer wall are folded inwards. In some cases it may be advantageous for the assembly edges to be folded outwards.

 Most frequently, the insulation elements correspond to half of a complete insulation around a pipe and the junction of two elements is done in the diametrical plane passing through the pipe. Other embodiments are possible such as for example those of a quarter of a circle or a third of a circle or even of a complete circle.

 Figure 2 shows the meeting and assembly of two elements 1 on a pipe 9. The nesting of the male / female assembly parts as well as the coming against one another of the folded edges, appear clearly.

Only the liaison bodies were not represented.

As elements 1 are identical, they can fit together. Because of this form identity, the drawings use the same references to designate the same parts of the elements.

 FIG. 3 shows a variant of an insulation installation comprising four elements 10 each corresponding to a quarter of the periphery. These elements 10 are assembled by their folded edges 11, 12 in the junction planes of each element 10.

 In this example, each element 10 is delimited by two radial junction planes making an angle of 900 between them. Such a decomposition of the insulation assembly into more than two elements may be advantageous, or even necessary in certain cases, when the piping includes, for example, different branches or tapping.

 Nevertheless, as far as possible, such fragmentation of the insulation assembly is avoided since this increases the manufacturing cost and that of the installation.

 FIG. 4 shows another example of an insulating element 20 according to the invention. This element is unique.

It actually consists of two pseudo-parts, joined by a link having to some extent an articulation effect and the manufacture of which will be described later. This element 20 consists of a single outer wall 21 with two folded edges 22, 23 and integrally carrying two circular half-cylinders 24, 25 of insulating expanded material, fixed to the wall and retaining its curved shape.

 In the middle 26 of the wall 21 of this element, the parts 24, 25 of insulating foam, substantially corresponding to the halves, are separated from the interior surface of the wall to facilitate the opening of this zone 26 forming a joint. For this, before introducing the foam, a strip 27 is applied to the inner face of the wall, along the zone 26 forming the hinge, the upper face of which is not adherent for the foam of the parts 24, 25 .

 The articulation 26 formed by the outer wall 21 allows the partial opening of the insulating element 20, sufficient to introduce the pipe 9 to be insulated and pass it through its reservation (28, 29) formed in half by cavities 28, 29 in each of the parts 24, 25.

 For the same reasons as above, the opposite faces of the two parts 24, 25 of the element 20 also comprise male / female assembly parts 30, 31, 32, 33 also forming a baffle for sealing and locking.

 The insulation element 20 is closed as in the other previous cases, by joining the folded parts edge to edge 22, 23 and blocking them by connecting members, not shown.

 In the various examples of the insulation elements 1, 10, 20 described above, the junction surfaces are provided with male / female assembly parts 7, 8, 30, 31, 32, 33 with triangular section; other forms are possible and the number of such parts may be different from that of the examples above.

 FIGS. 5A-6 show an example of a procedure for manufacturing insulating elements such as that of FIG. 1.

 According to FIG. SA, starting from a sheet 40 of sheet metal or of plastic, the edges 41, 42 of which are or will be folded square, possibly with complete folding to have a double thickness 43 according to FIG. 5B, uses the elasticity of the sheet to give it the shape of a half-cylinder (Figure 5C) and we block this shape in a corresponding template 43 (Figure 6). Depending on the length of the insulating element to be produced, a certain number of templates is distributed along the length.

 The mold thus formed by the curved sheet 40 is completed by a cover 44 provided with a tubular middle part 45 forming the molding core constituting the reservation intended for the pipe to be insulated.

 This cover 44 has the shapes 46, 47 of the assembly parts. It consists of a plate reinforced by crosspieces 48, for example in line with the templates 43.

 When the mold is thus formed, the insulating foam 49 is injected which clings to the wall 40 and blocks its curved shape. However, this foam does not adhere to the cover 44.

 The assembly is assembled by removable assembly means to facilitate the opening and demolding of the insulation element, such as those represented in FIG. 11.

 The length of the insulation element can be standardized or made to order. It suffices to use a sheet 44 of appropriate length and to adapt the templates 43 and the covers 44. The ends of the insulation element are made so as to facilitate the longitudinal junction, giving it insulation characteristics. and mechanical strength.

 FIG. 7 shows an example of a cover 50 formed of a tube 51 at the outside dimension of the reservation for the pipe. This tube 51 integrally carries longitudinal bars 52, 53, for example welded; these bars 52, 53 are located above the median plane 54 of the tube 51. The bars 52, 53 removably carry wings 54, 55 whose shape corresponds to that of the junction surfaces to be produced.

 The templates make it possible to manufacture the insulation elements of defined diameter as a function of physical parameters, according to the insulation characteristics to be obtained.

 For the same template, different covers can be chosen according to the section or shape of the pipe to be insulated and the shape of the assembly parts to be molded.

 FIG. 8 shows in section the production of an insulating element such as that of FIG. 4. For this, a lower template 60 is used having a semicircular cavity 61 to receive the part of the sheet 62 which forms half of the wall of the insulating element. This lower template 60 is completed after the establishment of the sheet 62 by two upper templates 63, 64 each time corresponding substantially to a quarter of a circle. Inside the sheet 61, placed in the lower template 60, a partition 65 is placed, arranged along a preferably vertical diameter for the vent holes in the upper part. This partition wall 65 is formed by a tube 66 of section corresponding to that of the pipe which will receive the insulating element. This tube carries two wings 67, 68 similar to those of the cover of FIG. 7. Depending on the case, the tube is in one piece and the wings are welded; it is also possible to have a tube divided into two halves attached to the wings which are then in one piece. This partition projects from above 69 of the closed tube formed by the sheet with folded edges 70, 71.

 After injection of the insulating foam forming the parts 72, 73, the insulation element thus manufactured is removed as shown in FIG. 8, by removing the upper templates 63, 64 then slight opening of the element to extract the partition 65 .

 As the wings 67, 68 have a certain thickness and in the case of a complete sheet for the entire periphery of the insulation, after molding there will remain a gap between the insulating parts that this gap of zero thickness at the folded edges 70, 71 increases to the thickness of the plate of the wings, at the other end, diametrically opposite that of the edges 70, 71.

 However, such an interval is inconvenient for the effectiveness of the insulation, so it is provided according to the invention, not to simply inject into the mold but to coat beforehand the surface of the wings and of the half-pipe with sheet of flexible foam and then injecting the actual insulating material 72, 73 so as to obtain insulating elements whose assembly surface will be formed by the sheets of foam. This will compensate for certain irregularities, particularly on the surface of the pipe (extra thicknesses due to weld seams, etc.).

 During the injection the insulating material sticks or clings to the sheet of foam, the latter not adhering to the walls of the mold.

 It should be noted that the sheet of foam is crushed at the time of injection in order to expand again after release from the mold and to be able to fill the gap elastically when the insulating element is placed around the pipe.

 The foam sheet may be an Armoflex (registered trademark) sheet.

 FIG. 9 shows an alternative embodiment of a partition 80 with adjustable wings 81, 82. They are slid into the diametric slots 83, 84 of a tube 85, between two guide plates 86, 87 and the assembly is locked at the chosen dimension with nuts 88.

 Figure 10 shows the establishment of an end flange 100 on the tube 101 of a mold, so as to achieve the end clearance for the assembly of two insulation elements in the extension one the other. This flange 100 is fixed against the wing 102 shown in a vertical position, using a fixing ring 103.

 The installation of this flange is the same if the wing is in a horizontal position.

 FIG. 11 shows a detail of the assembly of a mold comprising, in addition to the pipe 66 and the wings 68, an outer envelope 73 which surrounds the sheet 62 with folded edge 70. This FIG. 11 also shows the sheet of foam 75 covering the pipe 66 and the wing 68.

 The edge 76 of the envelope 73 is folded and bears against the top 69 of the wing 68.

 The envelope 73 is provided with a tab 77 for assembly to close the mold. Holes 78 in the envelope 73 allow the evacuation of the gases which appear during the injection through the vents 74 of the sheet 62.

 FIG. 12A is a half-section showing an alternative embodiment of the ends 122, 123 to be joined of two insulation elements 120, 121 mounted on a pipe 124.

 The end 123 of the left element 121 according to FIG. 12A comprises a flange 125 held by a peripheral groove 126 produced in the wall of the element 121 while the end 122 of the right element 120 comprises a peripheral bulge 127 and a flange 128.

 The relative elasticity of the insulating foam makes it possible to push the end and the flange 125 of the left element 121 into that 122 of the right element 120 by pushing the corresponding flange 128 which is not retained by the wall. The assembly produced is presented as indicated by the half-section of FIG. 12B.

 FIG. 13 shows an insulation element 130, the two ends 131, 132 of which are extended by the wall. The elements meet end to end on the pipe 133, as shown in FIG. 15 and in the interval 134 between the two elements 130 foam is injected to complete the insulation; externally, the junction is closed by a ferrule 135.

 Figures 15 and 16 show a possible embodiment of the insulation elements intended for an elbow.

 For this, a part 140 in the form of a torus cut along its diametrical plane (in the form of a cake pan) is produced by pushing back; this part will constitute the outer wall of several insulation elements 141, 142, 143, 144 in particular of four insulation elements each corresponding to an elbow of 900 and forming a total of 3600.

 In each sector of 900, the inner edge 144-147 and the outer edge 148, 149, 150, 151 of the sheet 140 are folded.

 This part 140 receives a cover 152 (FIG. 16) with flanges 153, 154, 155, 156 of radial subdivision and an O-ring core 157 forming the reservation for the pipe bend to be insulated. The insulation foam is then injected into this mold. The foam sticks to the pushed back piece but not to the cover. For demolding, the cover and its O-ring core are removed. We obtain a set of four insulation elements for elbows at 900.

 It suffices to cut or saw this piece along the four spokes. In the most frequent case one cuts according to arcs of angles of 900 but other usual angles are possible, for example 450 or 1350, according to the needs.

 The assembly of the elbow insulation elements is done like the assembly of the straight elements, by an edge-to-edge mounting using assembly members such as pliers.

Claims (12)

CLAIMS 1 ") Insulation assembly for a pipe, formed of insulating elements surrounding the pipe, assembly characterized in that - each insulation element (1) comprises an external wall (2) curved in the form of a trough, constituted a relatively rigid sheet ending in folded edges (4, 5) and corresponding at least to a fraction of the periphery of the insulation to be produced, trough receiving an insulating part (3) leaving a reservation (6) of shape and dimensions corresponding to those of the pipe to be insulated, this insulating part (3) forming the joining surfaces bounded by the folded edges (4,  5), - the closing of an insulation element (1) on itself or  the assembly of insulation elements to each other is  edge to edge (4, 5).  20) An assembly according to claim 1, characterized in that the outer wall (2) is a sheet of sheet metal or plastic.  30) An assembly according to claim 1, characterized in that the edges (4, 5) of the sheet are folded in the junction plane.  40) An assembly according to claim 1, characterized in that the junction planes comprise male / female assembly parts (7, 8), homologous, extending over the entire length of an insulation element (1) .  50) An assembly according to claim 1, characterized in that the ends of the sheet forming the outer wall of the elements (100) are provided one with a groove (126) and the other with a domed crown (127) of section corresponding to that of the groove (126) to allow the end-to-end fitting of the elements.  60) An assembly according to claim 1, characterized in that the insulating element consists of a curved sheet (21) corresponding substantially to the periphery of the insulating element to be produced, and whose longitudinal edges (22, 23) are curved at right angles, this sheet (21) carrying two parts of foam (24, 25) each corresponding to one half of all the insulation, bordered on one side by the respective edge (22, 23) folded down from the wall (21), the middle of this wall (21) constituting a longitudinal articulation (26) making it possible to at least partially open the two halves to surround a pipe.  70) An assembly according to claim 1, characterized in that the outer wall (140) is in the form of a toroidal neck receiving an insulating part with a reservation also in toric form.  80) A method of manufacturing a pipe insulating element according to any one of claims 1 to 5, characterized in that - a sheet (40) of width corresponding to the  peripheral length of the insulation element to be produced  and the longitudinal edges (41,  42) of this sheet (40), - the sheet is placed in a bending jig (43) to  form a chute corresponding to at least a fraction  from the periphery of the insulating element to be produced, - the cover is covered with a cover (44) carrying a tube  (45) corresponding to the dimensions and the position of the  pipe which must receive the insulation, - foam (49) is injected into the mold thus formed  so that the foam sticks to the inside of the  curved sheet (40) and blocks its bending.  90) A method of manufacturing a pipe insulation element according to claim 8, characterized in that one takes a sheet (62) of width corresponding to the periphery of the insulation of the pipe to be produced, this sheet is folded , partially in a template (60, 61) corresponding to a semicircle, then a diametral partition (65) is placed inside the trough thus produced with the sheet, the lateral edges of the sheet are closed to form a complete envelope and the bending thus produced is blocked using complementary templates (63, 64), the curved edges (70, 71) of the sheet forming the wall joining against the partition (65), the partition (65 ) carrying a tube (66) in the central position to form the molding core constituting the reservation of the pipe to be insulated, then the foam is injected into the mold thus formed, after having if necessary coated the pipe 66 and the partition with a sheet of foam which will bond to injected foam.  100) Method according to claim 9, characterized in that in the longitudinal region (26) of the sheet (21), forming the hinge for opening the two halves of the insulation element, an adhesive strip is placed ( 27) on the inner face of the sheet, the outer surface of this strip not being adhesive for the foam of the insulation element, then the foam is injected so as to allow the foam to peel off from the inner surface of the leaf at the level of the area forming the joint.  110) Method for manufacturing an insulating element for wrapping an elbow, according to claim 7, characterized in that - a part (140) in the form of a torus cut according to one is produced  its diametral plane, - a cover (152) fitted with flanges of  radial subdivision (153-156) and an O-ring (157)  for the reservation of the pipe, - we inject the foam, and we cut the assembly after removing  cover covering along shelves and arcs  angular wanted for the elbows.