HK1129919B - Pre-applied protective jacketing construction for pipe and block insulation - Google Patents

Description

Pre-applied protective jacket construction for tubular and block insulation

Related U.S. application information

This application claims priority from united states provisional application No. 60/887,892, filed 2/2007, according to 35 u.s.c. § 119 (e).

Technical Field

The present invention relates to improvements in jacked pipe insulation and equipment insulation that help provide weather protection, secure insulation to the pipe or equipment, and protect the insulation from physical damage and corrosion. The present invention also provides a pre-applied jacketed insulation that is superior in installation to the prior art.

Background

Insulation is commonly used in many industries to prevent the loss or absorption of heat from pipes and equipment. When insulation on pipe and equipment is exposed to the external environment, the insulation becomes wet, resulting in physical degradation, reduced thermal efficiency, and corrosion of the pipe or equipment it is insulating. Therefore, an additional outer layer, commonly referred to as a protective jacketing (sometimes also referred to as a sheath or cladding), is installed over the insulation to protect it from weather and physical damage. There is a lack in the insulation art of protective jacketing construction that allows for a protective jacketing to be pre-applied to insulation and then shipped to an industrial site so that it can be installed on pipe and/or equipment easily, quickly, and efficiently.

The protective sleeve material comprises a metal sheet, a plastic sheet, a metal foil/plastic laminate or a metal foil/glass fiber cloth laminate. The insulation is generally not adhered to the industrial insulation at the factory prior to shipping it to the industrial site. Instead, the insulation is first shipped to the industrial site, installed on the pipe and/or equipment, and then the jacketing is installed separately on the surface of the insulation and simply secured or tied together. The reason for this is that most industrial insulation surfaces are dusty and fibrous. This surface feature does not allow direct bonding of the insulation to the protective sleeve. This method of installation in the industrial field thus requires much time and labor. According to this method of installation, the protective jacketing must be installed and sealed separately after the insulation is installed and secured with tape or rope or tie.

The actual installation method of the thermal insulation industry is as follows: the insulation and protective jacketing are shipped to the industrial site, then the insulation is installed on the pipe or equipment, secured in place with tape, rope or tie, and finally the protective jacketing is installed separately. A disadvantage of this approach is that when the insulation and protective jacketing are secured together, there is a slight gap between the various tiers where the jacketing overlaps or where the jacketing surrounds the round tubular insulation. Movement of the protective sleeve relative to the insulating material and surfaces insulated thereby, due to movement of the pipe or equipment and/or differences in thermal expansion and contraction, destroys the integrity of the seal. Such seal imperfections can allow water or other electrolyte to enter the insulation and be absorbed or condensed onto the insulation, resulting in CUI. The present invention overcomes the above-described deficiencies by first providing an industrial insulation adapted to be directly bonded to a protective jacketing.

It is desirable to provide insulation that is suitable for uniform bonding or adhesion to protective jacketing. Such an insulation base would eliminate the possibility of movement of the insulation jacket after the insulation-jacket construction is installed on the pipe or equipment. This allows the protective sleeve to be applied in a factory setting, thereby greatly reducing installation time (and cost) in the field (e.g., by reducing the tools, labor, and materials used). Before the present invention emerged, protective jacketing had to be installed manually on the insulation at the site of the pipe or equipment requiring the insulation, since most insulation materials were brittle. This protective jacketing-insulation composite construction serves to protect the protective jacketing-insulation bond from typical industry factors. The present invention is directed to meeting these needs as well as others.

Corrosion of metal pipes or equipment that occurs under insulating conditions is known as Corrosion Under Insulation (CUI), which is a major problem for most process industries including, but not limited to, petroleum, chemical, food, and paper. Typically, corrosion of the tubular and/or equipment is not discovered until a system failure occurs. Pipe or equipment leaks, disasters caused by leaks, long downtime, and high maintenance costs are all caused by CUI.

While corrosion can be easily detected by viewing the outer surface of the pipe or equipment, the insulation and protective jacketing on the outer surface of the pipe or equipment insulation prevents viewing of the pipe or equipment. Since water intrusion into insulation is unpredictable, and CUI is unpredictable, a complete check of the entire insulation system will be effective. It is difficult and costly to find the particular portion of the pipe or piece of equipment that is corroded.

For corrosion to occur on metal pipes or equipment, it is necessary to have: (1) an anode; (2) a cathode; (3) an electrical circuit created by the potential difference of the anode and cathode; and (4) an electrolyte. All metals are themselves anodes, cathodes and circuits (i.e., the metal surfaces of the pipe or equipment). The rate and frequency of electron migration between the anode and cathode is related to the tendency of the pipe or equipment to corrode and varies with the pipe or equipment material, its contents, and the operating temperature of the system, among other things. Although CUI can be partially prevented by the choice of the insulating substrate in the early days, CUI can easily occur if the electrolyte enters through the moist insulation. From a cost perspective, it is not appropriate to replace existing pipe or equipment, so the substrate cannot always be selected. It is therefore particularly desirable to limit the contact of the electrolyte (in most cases water) with the insulation surrounding the pipe and equipment, as well as with the pipe and equipment itself, by insulating the insulation from the outside environment. The present invention has been developed in order to satisfy this need.

There are methods to detect CUI before system failure, such as removing insulation and then inspecting the pipe or equipment with a hygrometer and infrared detection. These methods are not only time consuming and costly, but often also require downtime. The use of a composite structure of insulation and protective jacketing can reduce inspection labor. If properly implemented (i.e., having a uniform interface between the protective sheath and the insulating material), the CUI inspection cost of the industrial system is reduced because no vapor is trapped between the protective sheath and the insulating material. Existing methods of providing a protective sheath allow the sheath to move and do not provide a seal with the outside environment. For example, metal tape has been used to join an aluminum protective jacketing to a tubular insulating material, which constrains the insulating material and the metal protective jacketing to the pipe, but does not prevent water ingress at the joints where the protective jacketing material overlaps itself or with adjacent parts. This approach leaves a gap between at least the outer surface of the thermal insulation and the protective jacketing, which in turn allows movement of the protective jacketing and water ingress.

Disclosure of Invention

One aspect of the invention relates to a method of inhibiting corrosion of a pipe, comprising the steps of: forming the porous heat-insulating body into a slender arc shape; applying a copolymer-sodium silicate solution layer to the insulation and at least partially within the pores of the insulation; allowing a threshold amount to be set for the copolymer-sodium silicate layer; after the threshold amount setting is completed, adhering the protective sleeve to the copolymer-sodium silicate solution layer; installing a protective jacketing-insulation composite structure on the outer surface of a pipe or piece of equipment; and sealing all exposed gaps or seams that may exist between multiple installed objects.

In another aspect, the sodium in the copolymer-sodium silicate solution layer is replaced by another metal of similar nature, such as potassium.

In another aspect, the porous insulation can be comprised of calcium silicate, mineral fiber, rock wool, slag wool, perlite, fiberglass, or a combination of these materials.

In yet another aspect, the insulation and protective jacketing can be joined together with a pressure sensitive adhesive or a contact adhesive.

In yet another aspect, the present invention relates to a coated insulation disposed on an exterior surface of a pipe adapted for adhesion of a protective jacketing. The coated insulation includes an elongated arcuate and apertured insulation having an outer surface with apertures and an inner surface sized to complement the outer surface of the pipe. The copolymer-sodium silicate layer is disposed on at least the outer surface of the insulation and within the pores.

In another aspect, the present invention relates to a method of preventing corrosion of a pipe, comprising the steps of: disposing a perforated insulating material around the pipe; applying a copolymer-sodium silicate layer as a coating to the insulation and at least partially into the pores of the insulation; and adhering an outer protective jacketing to the sodium silicate solution layer.

In a further aspect of the invention, there is provided a protective jacketing-insulation composite structure for an outer surface of a pipe or piece of equipment, wherein an elongated arcuate insulation is made of a porous material and has an inner surface and an outer surface, the inner surface being sized to fit over the outer surface of the pipe; the structure also includes a copolymer-sodium silicate layer located on the outer surface of the insulation and located in the pores of the insulation; and an outer protective sheath continuously joined with the copolymer-sodium silicate layer.

In yet another aspect, the insulation of the present invention is formed from first and second elongated arcuate insulation members capable of being joined together to form a tube that conforms to the pipe elements.

In yet another aspect, the protective jacketing includes a release layer of pressure sensitive adhesive for joining two insulating material members together.

In yet another aspect of the invention, a kit is provided that includes a protective jacketing comprising a release layer of pressure sensitive adhesive joining two arcuate insulation members that are capable of being joined together to form a tubular shape conforming to a pipe fitting. The insulation member includes a copolymer-sodium silicate layer disposed on an outer surface of the member and at least partially disposed in the pores of the outer surface. The kit also includes a contact adhesive that seals any cracks or edges between adjacent protective sleeves.

Drawings

Fig. 1A is a schematic view thereof showing a composite structure of a protective sheath and an insulating material according to an embodiment of the present invention, wherein the composite structure is installed around a pipe.

FIG. 1B is a schematic representation of one embodiment of the present invention showing a rectangular block of insulation coated with a copolymer-sodium silicate composition.

Figure 2 is a cross section of one embodiment of the invention installed around a pipe.

FIG. 3 is a schematic representation of one embodiment of the present invention showing an elongated arcuate insulation coated with a copolymer-sodium silicate composition.

Fig. 4 is a cross-section of a jacketed insulation material as one embodiment of the present invention.

Fig. 5 is a detailed view of a portion of the cross-section of fig. 4.

Fig. 6 is a graph of the thermal conductivity of a calcium silicate insulation.

The flow chart shown in fig. 7 includes steps for manufacturing a jacketed insulation material according to one method of the present invention.

Detailed Description

Industries such as petroleum, chemical and food processing require systems that operate over a wide temperature range. During system operation, it is desirable to keep energy consumption to a minimum while keeping efficiency to a maximum by surrounding the pipe and equipment with insulation. Such insulation also protects operators who access the pipe and equipment from burns and skin damage. Insulation for a wide range of applications should be able to withstand high temperatures and must have high structural strength.

The high mechanical strength and high temperature capability of the insulation (fibrous and porous structure) also makes the insulation surface brittle over a large area (i.e., with dust and loose fibers), thereby preventing the adhesive bond between the protective jacketing and the insulation from providing the desired jacketing-insulation construction.

In accordance with the present invention, insulation bonded to protective jacketing can provide weather protection and physical damage protection with high structural strength, and can prevent pipe or equipment corrosion from occurring between the outer surface of the pipe or equipment and its insulation. Protective jacketing-insulation composite structures are used to improve installation efficiency on pipe and equipment, thereby reducing installation time and cost.

FIG. 1A generally illustrates a jacketed insulation (also referred to herein as a "composite structure") according to one embodiment of the invention. FIG. 1A shows a jacketed tubular insulation 120 pre-applied with a protective jacket, which is placed around a conventional pipe 20. The insulation 120 has an inner surface 10 and an outer surface 30 and includes two apertured arcuate insulation members 50, each insulation member 50 having an inner surface 40 and an outer surface 60. According to one embodiment of the present invention, the insulation has a copolymer-sodium silicate solution 70 disposed on the exterior surface 60 and in the pores thereof. After the coating is applied, the protective jacketing 90 is adhered directly to the coated insulation 75, with the protective jacketing 90 being bonded to the coating by the adhesive contact agent 80 (see FIG. 2). Such adhesive contact agents may be pressure sensitive or contact sensitive. The two arcuate insulating members 50 are joined together by a pressure sensitive adhesive 100. These parts will be explained in turn below.

Preferably, the insulation 50 comprises a substrate having a copolymer-sodium silicate coating with a smooth surface free of dust and loose fibers. In certain embodiments, the substrate is a calcium silicate insulation composed of: greater than or equal to 93% calcium silicate (CAS #1344-95-2), 0 to 2% man-made glass fiber (CAS # 65997-17-3), 0 to 6% sodium silicate (CAS #1344-09-8), 0 to 2% cellulose fiber (CAS # 9004-34-6), and less than 1% iron-based pigment (CAS # 51274-00-1).

In another embodiment, the insulation is comprised of rigid expanded perlite insulation and mineral fiber insulation or a combination of both. The mineral fibers consist of rock wool, slag wool or glass fiber products or a combination of these mineral fibers.

The properties (e.g., physical properties, dimensional tolerances, and quality requirements such as compressive strength and heat transfer rate) of the Block and arc Insulation provided herein meet or exceed American Society for Testing and Materials (ASTM) requirements (ASTM Specification C533: "Standard and tubular Insulation Standard Specification for Calcium Silicate Block and Pipe Insulation"), Specification C610: "Standard and tubular Insulation Standard Specification for Molded Expanded Perlite Block and Pipe Insulation", Specification C547: "Standard and Standard Fiber tubular Insulation" and Specification C612 "Standard and Standard Fiber Standard and plate Insulation" for Mineral Fiber tubular Insulation ". The thermal conductivity of the insulation was determined using ASTM test methods C335, C177 and C518. Figure 6 shows the thermal conductivity ("k") versus average temperature for a preferred arcuate composite insulation, i.e., a calcium silicate insulation having a sodium silicate solution layer disposed on the surface thereof.

In one embodiment, shown in FIG. 1B, the insulation 50' may be in the form of a block (e.g., a parallelogram) having a thickness of, for example, from about 25mm to about 114 mm. Such block insulation can be rectangular and have a grooved inner surface 40' and then can be formed into the desired shape to fit around the target structure. For example, if the block insulation 50 'is wrapped around a tubular structure, with the narrow grooves on the inner surface 40' facing the pipe, the grooves shrink tightly together as the block insulation is bent around the pipe. The exterior surface 60 'of the insulation 50' can be provided with a copolymer-sodium silicate solution layer 70 such that when the insulation is formed into a desired shape, the copolymer-sodium silicate solution layer 70 is contained therein. In this manner, the outer surface is continuously coated (not shown in FIG. 1B) to provide a smooth, uniform and flat surface for the protective casing to be applied. The resulting flat outer surface is polygonal. In certain embodiments, bulk insulation is used to surround a large diameter cylindrical surface.

In certain embodiments, the exterior surface 60 'of the insulation 50' is provided with a pre-applied copolymer-sodium silicate solution layer 70 such that the copolymer-sodium silicate solution layer 70 is contained therein when the insulation is formed into a desired shape. In other embodiments, the copolymer-sodium silicate solution is applied to the exterior surface of the insulation after the block insulation is formed into the desired shape. In certain embodiments, a copolymer-sodium silicate solution layer is applied to each surface of the block of insulation (e.g., by immersing the insulation in such a solution).

As shown in fig. 1A and 3, the insulation can also be provided as an elongated arcuate member 50 having an inner surface 40 shaped to conform closely to the outer surface 30 of the pipe or equipment. For example, two elongated arcuate insulation members can be provided to completely surround the outer surface 30 (FIG. 1A) of the pipe 20. The end user can specify the dimensions of the tubular insulation. In some embodiments, the tubular insulation is about 914mm (about 3 feet) in length and between about 25mm and about 152mm in thickness, for example. However, the insulation can have other thicknesses for a given situation.

To provide a protective sleeve for a pipe or piece of equipment, the protective sleeve applied over the insulating members 50 and 50' comprises a laminate of metal foil, plastic film and/or fiberglass cloth, or another protective sleeve material such as metal sheet. However, the apertured insulation 50 and 50' itself is not suitable for bonding to the protective jacketing 90 due to its fragility and dustiness. If the protective jacketing is applied directly to the insulation, the protective jacketing 90 will still allow electrolyte (i.e., water) to enter the insulation. Because the insulation has voids and/or fibers, the contact cement or pressure sensitive adhesive used to bond the protective jacketing to the insulation will not provide a uniform interface between the protective jacketing 90 and the insulation exterior surfaces 60 and 60'.

Referring to fig. 1A, a sodium silicate polymer solution having a suitable viscosity is applied on an outer surface 60 of the insulation material 50. Although sodium silicate polymer solution is used herein, in certain embodiments, other metals (e.g., another main group metal) having properties similar to sodium can be substituted for sodium. The particular coating provides a continuous and uniform bond of the outer surface of the insulation to the protective jacketing, while the coating is able to at least partially enter the pores of the insulation. The selected solution, when disposed on the insulation material, will at least partially enter the pores without substantially (e.g., significantly) affecting the insulation properties of the unaltered insulation. For the insulating members 50 and 50', the coating can be a liquid composition based on a copolymer of sodium silicate. In certain embodiments, the liquid composition based on copolymer of sodium silicateComprising 7.5% to about 15% sodium silicate (CAS # 1344-09-08). In the present invention, the other ingredients of the sodium silicate copolymer-based liquid composition may include any of the following: potassium hydroxide, sodium nitrite, methyl cellulose calcium carbonate, glycerol, elastic copolymer, acrylic ester, sodium polyacrylate, sodium polystyrene sulfonate, ethylene-vinyl acetate, ethylene-methyl acrylate, titanium dioxide and copper sulfate. In one embodiment, the sodium silicate composition is RainKote diluted in water at a rate of 50%^TM，RainKote^TMIs a product of Industrial Insulation Group ("IIG") company, Inc. of Delelix, Georgia, the web site of IIG company is International Insulation.

The viscosity of the solution may vary when it is applied to the substrate, depending on the composition and porosity of the insulation. In addition, each base layer is adapted to a certain solution viscosity range according to its characteristics. If the solution is too viscous, it will not enter the pores of the insulating member and thus provide a flat smooth surface for lamination applications, but this may result in delamination. At the other extreme, if the solution is not sufficiently viscous, it can penetrate into the pores of the insulation, thereby affecting the insulation properties and failing to provide a uniform contact surface (i.e., the surface area of the coated insulation is comparable to the surface area of the uncoated insulation). A solution with an intermediate viscosity will at least partially sink into the pores and provide a substantially flat surface that is substantially chemically uniform.

A solution of suitable viscosity will be at least partially imbibed into the upper surface (including the pores) after application to form a substantially chemically uniform (homogeneous) layer, thereby preventing gaps between the coated insulation and the protective jacketing layer.

It will be clear to one of ordinary skill in the art how to select an appropriate viscosity for application of the solution to a particular substrate. The viscosity of the solution will vary depending on the specific properties of the insulation, such as the size of the pores and the spacing of the pores. Testing is one way to obtain the preferred viscosity of the silicate solution. First, a base layer is selected for the application solution. The copolymer-sodium silicate solution (or the sodium silicate can be replaced by a metal silicate having similar chemical and functional properties to sodium silicate) is then continuously (or in another way) diluted and the resulting solution applied to the insulating member or portion thereof. Depending on the ease of application, the nature of the coating (e.g., thickness, uniformity, smoothness, etc.), and whether a protective jacketing can be attached, it will be apparent to one skilled in the art what solution viscosity to use is to provide the desired base for applying the protective jacketing.

Table 1 provides examples of how solutions of various viscosities can be prepared for use on calcium silicate insulation. Mixing the RainKote^TMThe solution was serially diluted (column 1 of table 1) and applied to calcium silicate insulation (substrate). In each case of the test, the solution can be sprayed using a Wagner paintSprayer Pro spray gun. The sprayed substrate is suitable for laminated applications. As can be seen from Table 1, a determinable viscosity from 80,000 centipoise (cP) to 323 centipoise (cP) is sufficiently sprayable and applicable when applying the copolymer-sodium silicate solution to calcium silicate insulation.

The copolymer-sodium silicate liquid composition disposed on the base layer is generally referred to as a "copolymer-sodium silicate solution layer" or an "elastomeric copolymer-sodium silicate layer".

The function of the elastomeric copolymer-sodium silicate layer 70 in the jacketing-insulation construction 120 is to fill the voids in the voided insulation 50 and 50' to form a uniform surface on the insulation for application of the jacketing 90 with a pressure sensitive adhesive or contact adhesive between the insulation and the jacketing.

After the copolymer-sodium silicate solution 70 is applied to at least the outer surface 60 of the insulation 50, it may be set to a threshold amount, optionally under controlled conditions of temperature, pressure and humidity. Thereafter, as shown in the cross-section of FIG. 2, a protective jacketing 90 is applied to copolymer-sodium silicate layer 70 by circumferentially surrounding pipe 20 with a pressure sensitive acrylic adhesive 80 (described below).

However, the protective jacketing 90 can be pre-adhered to the insulation 50 prior to shipment to the industrial site, allowing for a one-step direct installation on a pipe or piece of equipment (see fig. 3 and 4). Thus, the end user can adhere the protective jacketing 90 directly to the coated insulation 75, such as by an acrylic adhesive or contact adhesive 80, or can pre-apply the protective jacketing 90 to the coated insulation 75 at the factory level and provide it to the end user. Alternatively, a pressure sensitive adhesive can be used in combination with another adhesive to bond the protective sleeve to the coated surface. For example, the seam and exposed edge can be sealed using a pressure sensitive adhesive (see fig. 3 and 4).

Applying the protective sleeve at the factory stage reduces costs associated with field installation. When the protective jacketing-insulation composite structure is installed in the field by one-step installation, materials, tools and labor are reduced. Reusability after maintenance is also an option of the present invention. The composite structure of the present invention can maintain a half-shell structure after being detached from the pipe, and thus can be repeatedly installed after maintenance. Insulation without a pre-applied protective jacketing generally cannot be reused due to excessive damage when the insulation is removed.

The present invention can also be used to inform the user when the composite insulation is being applied. The copolymer-sodium silicate solution can be dyed (e.g., blue) or marked (e.g., using nanostructures or other markers in the sodium silicate solution) to distinguish the coated insulation from other insulations. So that the authenticity of the protective sleeve-insulating material structure can be distinguished by visual inspection or measurement inspection.

In the exemplary embodiment shown in FIG. 3, the protective jacketing 90 has been adhered to the coated insulation 75, which is made of aluminum foil, nylon cloth, or nylon cloth, while being transported to the job siteA laminate 190 of fiberglass cloth, an adhesive 195, and a release layer 200 beneath the adhesive. The release layer 200 serves to protect the adhesive 195 and is released after the protective sleeve is installed around the pipe. The protective sleeve is typically a multi-layer metal foil/plastic film laminate, such as VENTURCALAD from Venture Tape, Rockland, Mass^TM1577 (five layers) or 1579 (thirteen layers) series aluminum foil/polyester film laminate protective sleeve. However, any protective jacketing capable of being bonded to an insulation can be used in the present invention, so long as the insulation comprises the coating described herein. Each VENTURECLAD^TMThe protective jacketing comprises a pressure sensitive adhesive layer and can be applied directly to the coated insulating member 75 without an intermediate layer. If desired, the applied protective jacketing can be flattened using a roller, such as a paint roller, to ensure a strong and uniform bond between the coated insulation and the protective jacketing.

When the jacketed tubular insulating material member 300 is in the form of an elongated arc, it may be joined by a protective sleeve sheet 190, the sheet 190 having a release layer 200 comprising a pressure sensitive adhesive. Two or more jacketed insulating members 300 can be joined by: as shown in fig. 3, the member 300 is wrapped around a pipe or piece of equipment; removing the release layer 200 to expose the pressure sensitive adhesive sheet 190; the pressure sensitive adhesive sheet 190 of one member is bonded to the other member. Alternatively, as shown in fig. 1A and 2, the apertured insulating members 50 can also be adhered to each other by a pressure sensitive adhesive 100 protected by a release layer 105.

In fig. 4, a cross-sectional view of two insulating members 300 is shown, the sheets 190 of the two insulating members 300 being attached to each other. As previously described, insulation member 300 is disposed about pipe 20 and includes insulation members 50 and 50 ', copolymer-sodium silicate layers 70 and 70', adhesive 80, and protective jacketing 90 (see FIG. 5). Preferably, the member 300 is arranged around the tube 20 such that the two tabs 190 face opposite sides of the tube, respectively. After removal of the release layer 200, the adhesive 195 will be exposed and the adhesive 195 can be contacted or crimped together with the outer surface 92 of the protective cover 90.

FIG. 7 illustrates steps for manufacturing a composite sock-insulation structure according to certain aspects of the present invention. An insulation 50 is provided at step 710. Prior to further processing, the insulation 50 can be formed or formed into an elongated arcuate member or other shape suitable for mounting to an exterior surface of a structure, as shown in block 750. The insulation 50 can also be pre-formed into a desired shape. The specific shape of the insulation will depend on the diameter of the pipe 20 or the shape of the structure to be covered. In step 720, a copolymer-sodium silicate-based liquid composition is applied to the insulation member 50 before or after it is formed into a desired shape.

In one preparation method, the copolymer-sodium silicate composition can be applied to the exterior surface 60 of the insulation 50 with a brush. Alternatively, the copolymer-sodium silicate composition is applied to the exterior surface of the insulation 50 by low pressure spraying. In yet another embodiment, the copolymer-sodium silicate coating 70 can be applied over the entire insulating member 50 by immersing the insulating material 50 in the copolymer-sodium silicate composition. In various embodiments, sodium is replaced with another main group metal or a metal that has similar chemical and functional properties to sodium. In certain embodiments, such metal is selected from alkali metals, such as sodium, potassium, lithium, cesium, or francium. In other embodiments, such metals are alkaline earth metals, which are similar to basic metals in terms of basic properties (as opposed to acidic) and high activity.

After the coating 70 is applied to at least the outer surface 60 of the insulation 50, a threshold amount can be set, as shown at step 730, by drying in a humid environment (passive drying) for a period of time or in an oven at 150 ℃ to 175 ℃ for a period of time (active drying). Alternatively, the coating can be dried using methods known in the art, such as vacuum methods. The insulation with the pre-applied protective jacketing can then be provided to the end user for installation on the pipe or equipment (fig. 3 and 4).

One or a combination of these coating methods may be selected depending on the desired thickness of the sodium silicate layer 70, the shape of the insulation 50, and the uniformity requirements for the elastomeric copolymer-sodium silicate layer 70. For example, the edges of the composite insulation may not be coated by spraying, but the portions of the insulation exterior surface 60 that cannot be sprayed can be coated by brushing.

In step 740, the protective jacketing 90 can be applied to the coated insulation member 75 by pressure adhesive or contact adhesive. In the embodiment shown in FIG. 3, the protective jacketing comprises an adhesive contact layer 80 and is applied to the coated insulation 75 by peeling away a protective release layer 200. Forcing the air bubbles out, for example, with a paint roller or the like, removes any air bubbles between the adhesive contact layer 80 and the coated insulation 75. If the insulation has not been shaped to conform to the structure to be surrounded, then this is done in step 750. The structure can be enclosed on site with insulation as previously described, as shown in step 760. According to various embodiments, these components may include a coated insulating material component 75 or an insulating component 300.

As shown in step 770, a transverse (i.e., radial) connection between the two components can be achieved using a protective sheath 90, adhesive 80, and release layer 200 made from the materials described above.

As can be seen from the cross-sectional view, the (possibly fully coated) elastomeric copolymer-sodium silicate layer 70 provides a uniform surface for bonding the protective jacketing 90 to the exterior surface 60 of the insulation 50. The uniform interface holds the protective jacketing 90 in place and allows no gaps to be created between the protective jacketing 90 and the insulation 50, or where the insulation overlaps itself or with adjacent insulation. The gaps formed between (1) the pipe outer surface 30 and the insulation inner surface 40, or (2) the insulation outer surface 60 and the protective jacketing 90, can allow moisture to enter the structure and create condensation of water, which in turn can lead to the generation of CUI.

Any existing coating can be applied to the outer surface of the pipe element according to the invention. The primary coating can help seal the pipe surface, but it is easily damaged during handling and does not always adhere completely to the pipe outer surface. The present invention provides additional resistance to corrosion and can be used as a supplement to the primary coating.

The present invention has been described in detail by way of exemplary embodiments, but the present invention is not limited thereto. The claims should be construed broadly to include other embodiments of the invention which can be made by those skilled in the art.

Claims (18)

1. A method of preventing corrosion of a tubular, comprising the steps of:

providing a composite pre-jacketed insulation product manufactured at a factory by:

(a) forming the porous insulation into an elongated arc;

(b) applying a copolymer-sodium silicate solution layer at least on the exterior surface of the insulation and at least partially within the pores of the insulation;

(c) allowing a threshold amount to be set for the copolymer-sodium silicate solution layer; and

(d) after the threshold amount setting is completed, adhering an outer protective sleeve on the sodium silicate copolymer solution layer;

installing the composite pre-covered insulation product on the outer surface of a pipe fitting at a working site; and

sealing any gaps or seams exposed between adjacent installed composite pre-jacketed insulation products or between laminates of the protective jacketing.

2. The method of claim 1, wherein the insulation is comprised of calcium silicate, mineral fiber, perlite, or a combination thereof.

3. The method of claim 1, wherein the step of affixing comprises affixing a continuous outer protective jacketing to the copolymer-sodium silicate solution layer without the use of any intermediate layer.

4. The method of claim 1, wherein the forming step comprises forming the first and second elongated arcuate-shaped insulation members to be combinable to define a tubular body.

5. The method of claim 4, wherein the first and second elongated insulation members are at least partially interconnected by an outer protective jacketing.

6. The method of claim 4, further comprising the step of bonding the first and second elongated insulation members to one another along a contact surface.

7. The method of claim 6, wherein the first and second elongated insulation components each have respective first and second edges, and the bonding step bonds the respective first and second edges to one another, wherein each edge extends the length of the insulation component and extends through the thickness of the insulation component.

8. The method of claim 6, wherein said bonding step comprises bonding said respective first and second edges together with a glue comprised of a copolymer-sodium silicate solution.

9. The method of claim 1, wherein the applying step comprises brushing the copolymer-sodium silicate solution onto the insulation.

10. The method of claim 1, wherein the applying step comprises spraying the copolymer-sodium silicate solution onto the insulation.

11. The method of claim 5, wherein the protective sleeve comprises a multilayer laminate of foil, plastic film, and optionally fiberglass cloth.

12. A composite structure for an outer surface of a pipe element, comprising first and second arcuate elongated portions spaced apart from one another, each of the first and second arcuate elongated portions comprising:

(a) an elongated arcuate insulation body of a voided material having an inner surface and an outer surface, the inner surface being sized to fit over the outer surface of the pipe element;

(b) a copolymer-sodium silicate layer formed from a copolymer-sodium silicate solution on the exterior surface of the insulation and in the pores of the insulation;

(c) an outer protective sheath joined to the copolymer-sodium silicate layer to define a unitary pre-bonded composite structure for one-step direct installation on the outer surface of the pipe,

wherein each of the first and second arcuate elongated portions has a first edge and a second edge such that when the first and second arcuate elongated portions are mated together, the first edge of the first arcuate elongated portion is mated with the first edge of the second arcuate elongated portion and the second edge of the first arcuate elongated portion is mated with the second edge of the second arcuate elongated portion, the outer protective sheath of the first arcuate elongated portion has a first sheet portion extending beyond the first edge of the first arcuate elongated portion, the outer protective sheath of the second arcuate elongated portion has a second sheet portion extending beyond the second edge of the second arcuate elongated portion, the first sheet portion has a pressure sensitive adhesive applied to the opposing first arcuate elongated portion along an inner surface thereon and the second sheet portion has a pressure sensitive adhesive applied to the opposing second arcuate elongated portion along an inner surface thereon An adhesive to allow the first and second arcuate elongated portions to fit together around the outer surface of the pipe elements, wherein the outer protective jacket comprises a laminate structure comprising at least one foil, the outer protective jacket being capable of bending to allow the first and second sheet portions to bend and conform to the arcuate shape of the first and second arcuate elongated portions.

13. The composite structure of claim 12, wherein the porous insulation is comprised of calcium silicate, mineral fiber, perlite, or a combination thereof.

14. The composite structure of claim 12, wherein the copolymer-sodium silicate layer is disposed directly on the exterior surface of the insulation without any intervening layer.

15. The composite structure of claim 12, wherein the copolymer-sodium silicate solution bonded to the exterior surface of the insulation comprises 7.5% to 15% sodium silicate, and further comprising an elastomeric copolymer.

16. The composite structure of claim 12, wherein the outer protective sheath is comprised of a laminate of a metal foil, a plastic film, and optionally a fiberglass cloth.

17. The composite structure of claim 12, wherein the copolymer-sodium silicate solution has a viscosity between 57cP and 80,000 cP.

18. The composite structure of claim 12, wherein the copolymer-sodium silicate solution has a viscosity sufficient to diffuse into the pores of the insulation.