RU2530985C2 - Assembly of heat insulation for process pipelines - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to pipe covering. Foamed rubber tubes or reels are used for covering process pipelines pipes and parts subject to pipe diameter to be laid in several plies subject to pipe covering. Heat insulation of connectors is composed of segments or section parts while zinc-plated steel case is used as protection shell. The latter is designed to be made for every part and part diameter separately with due allowance for geometrical sizes and coveting depth. Case is secured with the help of tapping screws while case tightness is ensured by foamed rubber.

EFFECT: reliable application of covering.

7 cl, 2 dwg, 2 tbl

Description

The invention relates to thermal insulation of technological pipelines mainly to thermal insulation of pipes and fittings of above-ground and underground laying.

The invention is known "Method of applying foam insulation" (see application RU No. 93009955/04, published July 20, 1996, IPC В29С 67/20), in which to heat the pipelines with foamed polymeric materials, the pipe is installed into the mold, the foam polymer composition is filled, the mold is closed foaming. The curing of the foam polymer mass is carried out with the activation of heat removal from the forming shell by supplying air to the technological zone with a given temperature.

The disadvantage of this method is the need for positive temperatures for its implementation.

The invention is known "Method of thermal insulation of a pipeline" (see application RU No. 2002131172/06, published June 10, 2004, IPC F16L 59/06, F16L 59/08), which proposes a method of thermal insulation of a pipeline by attenuating radiant heat exchange and eliminating convection between the pipeline and environment, including the installation of support rings, to which the shells of reflective heat-conducting material are attached, one above the other with a gap creating air cavities.

The disadvantage of this method is the difficulty of its practical implementation in the field.

The invention is known "A method of applying thermal insulation to pipes with filler grades of polyurethane foam for air surface and underground laying" (see application RU No. 2009100548/06, published July 20, 2010, IPC F16L 59/00), including a thin sheet section concentrically mounted on the pipe, which is also a form and shell; filling the annular cavity through the upper longitudinal joint of the shell of the annular cavity with “filling” polyurethane foam grades and holding the time for its structuring; characterized in that the proposed method allows thermal insulation of pipes (pipelines) using the chain method, not only in the factory (using prefabricated polyethylene or spiral sheaths of sheet metal to a standard pipe length) and with limited use of polyurethane foam grades, and in any non-equipped place (using sections of thin-sheet shells of arbitrary length) and the use of "pouring" grades of polyurethane foam with vapor-waterproof properties.

The disadvantage of this method is that it is not applicable in the field at low temperatures, because the use of polyurethane foam filler grades requires positive temperatures.

The invention is known "Method of implementation of a collapsible heat-insulating coating of the pipeline" (see patent RU No. 2343340, application No. 2007120773/06, published January 10, 2009, IPC F16L 59/00, F16L 59/02).

The invention relates to the field of industrial and civil engineering and relates to a method for the implementation of a collapsible heat-insulating coating of a pipeline with a temperature of the transported agent from minus 180 ° C to plus 170 ° C. In the method, which includes installing composite shells as a coating along the length of the pipeline, fastening them with bandages and protecting the joint seams, the composite shells use a monolithic modular element of full factory readiness with two heat-insulating layers and a protective cover, the inner layer facing the pipeline made of rigid polyisocyanurate foam having a softening temperature of 170 ° C, and the outer layer is made of molded polyurethane foam with a mutual displacement of the layers each other, ensuring the presence of elements of thermal locking joints of the protrusion-trough type along the entire contour of the modular element, the shells are installed by stitching them around the perimeter and in length using transverse and longitudinal thermal locking joints and with the displacement of transverse seams by half the length of the shell, and the seams seal. This method is used only on straight sections of steel pipelines.

The disadvantage of this method is the impossibility of its application for the connecting parts of process pipelines.

Closest to the proposed method is a method of installing insulation, described in the "Installation Instructions Aeroflex" (LLC "Management company" Alfa-Invest, 2010, p.1-20), which is adopted as a prototype of the invention.

The disadvantage of this method is the use as a protective shell of a coating layer consisting of fiberglass, which does not protect the thermal insulation from environmental influences and mechanical damage.

The objective of the invention is to provide thermal insulation of technological pipelines, including their connecting parts.

The technical result that can be obtained by implementing the present invention is to maintain the temperature of the transported raw materials and the possibility of applying the proposed method of installing thermal insulation not only in straight sections of steel pipelines, but also for their connecting parts.

The technical result is achieved by the use of composite shells as heat insulation of technological pipelines - segments of foamed rubber in the form of tubes or rolls, which are installed if necessary in several layers. The number of layers is determined depending on the required thickness of the insulation. For the insulation of the connecting parts, foam rubber segments are used in the form of sections glued with glue, and a galvanized steel casing is used as a protective sheath, which is individually designed and manufactured for each pipe and connecting piece diameter, taking into account their geometric dimensions and thermal insulation thickness. The casing is secured using self-tapping screws, and the tightness of the casing connection is ensured by the use of foam rubber segments.

Installation of thermal insulation of technological pipelines includes preparing the surface of the pipeline and applying foam rubber segments in the field: for pipes and fittings with a diameter of less than 159 mm - in the form of tubes, for pipes and fittings with a diameter of more than 159 mm - in the form of rolls (sheets). Shells are made from tubes and rolls.

The width, thickness and length of the segments depends on the specific characteristics of the pipes and fittings of the process pipelines. Depending on the calculated thickness of the thermal insulation, foam rubber segments in the form of rolls (sheets) can be applied with a second and third layer. Installation of the second and third layer should be done with overlapping seams of the previous layer. When installing thermal insulation, all joints of thermal insulation are glued with glue. The edges of the shell should be glued to the pipe (connecting part) and to the thermal insulation of the previous section of the insulated pipeline.

A galvanized steel casing is applied to the insulation. The use of a casing of two halves of a sheet of galvanized steel is allowed, while the longitudinal edges of the upper half of the casing must be superimposed over the edges of the lower half. Stainless steel self-tapping screws are used to secure the casing. Screws are installed every 70-100 mm, the distance from the overlap edge is at least 10 mm.

Before installing thermal insulation, the surface of the pipeline is dried, cleaned of dirt, dust, ice, moisture and other contaminants.

For the thermal insulation of connecting parts in the form of transitions, factory-made foam rubber segments in the form of tubes or rolls are used, taking into account the thickness of the anti-corrosion coating of the transition.

The invention is illustrated by drawings of Fig.1-Fig.6.

Figure 1-2 shows the insulation of the segments of foam rubber on the pipe in two layers, figure 3-4 is the insulation of the segments of foam rubber at the outlet in one layer, figure 5 - the insulation of the segments of foam rubber on equal pass tee in one layer, Fig.6 - thermal insulation from segments of foam rubber at the transition to a single layer, Fig.7 is an example of fastening the casing.

Process pipelines include steel pipes and fittings for above-ground and underground installation.

Installation of thermal insulation on the pipeline is carried out after the positive results of hydraulic tests of the pipeline or pipeline section and corrosion protection of welded joints with the use of coatings based on heat-shrinkable polymer tapes of a multilayer construction.

Composite shell-segments made of foam rubber are used as thermal insulation of pipes and connecting parts of technological pipelines.

Segments can be made in the form of tubes and rolls (sheets) with a thickness of 25 and 50 mm. Depending on the required thickness, the thermal insulation is laid in one or more layers.

Work.

Before installing thermal insulation, the surface of the pipeline is dried, cleaned of dirt, dust, ice, moisture and other contaminants.

The thermal insulation material must be dry and without damage before installation.

The seams of shells, segments and sections of foamed rubber (longitudinal and transverse) 1 (Fig.1-8) are glued with glue based on polychloroprene rubber.

Segments of foamed rubber 2 (Fig.1-8) for thermal insulation of pipes and fittings of technological pipelines with a diameter of less than 159 mm are used in the form of tubes, for large diameters - in the form of rolls (sheets).

If the required thickness of the insulation exceeds the thickness provided by the nomenclature of tubes, rolls (sheets), the insulation from the rolls (sheets) is laid in the second and third layer.

Installation of the second, third layer of thermal insulation on the pipe (connecting part) is performed with overlapping seams of the previous layer, the distance between the seams is at least 50 mm.

For thermal insulation of pipe bends, equal bore tees, transitions, foam rubber segments are used in the form of sections cut from tubes or rolls (sheets). The number of sections and their sizes are determined depending on the angle and radius of the pipe outlet. When installing the sections, the edges of the sections are glued to the branch (tee, transition) and to the previous section of the insulated pipeline.

When installing foam rubber segments, the sizing of the joints and the position of the joints relative to each other are checked. The offset of the joints (transverse and longitudinal) on the pipes relative to each other should be at least 50 mm.

As a protective shell, a casing made of galvanized steel 3 (Figs. 1-8) or of two halves of a sheet of galvanized steel is used. The casing is designed and manufactured individually for each diameter of the pipe and connecting piece, taking into account the geometric dimensions of the pipe and connecting piece, as well as the thickness of the thermal insulation.

The overlap value of the casing sheet is performed in accordance with table 1.

Table 1 Overlap Pipe diameter The size of the overlap, mm up to 273 mm incl. from 20 to 50 over 273 to 530 mm incl. from 30 to 70 over 530 to 820 mm incl. from 40 to 80 over 820 mm from 50 to 100

The longitudinal seams of the overlap of the pipe casing made of two halves of a galvanized steel sheet should be located in the position corresponding to 3 and 9 hours, while the top sheet should go to the bottom. The position must be presented along the process pipeline according to the clock hands.

The longitudinal seams of the overlap of the casing of the connecting parts, made of two halves of a galvanized steel sheet, should be located in the position corresponding to 12 and 6 hours. The position must be presented along the process pipeline according to the clock hands.

The casing is fixed in the overlapping zones every 70-100 mm. For fastening the casing, self-tapping screws made of stainless steel 4 are used (Figs. 7-8). The distance from the edge of the overlap is at least 10 mm.

The tightness of the casing connection is ensured by the use of foam rubber segments.

When installing a casing, consisting of two halves of a sheet of galvanized steel, the length of one half of the casing is determined by the formula

L = (π · D) / 2 + N,

where D is the outer diameter of the installed pipe insulation, mm,

N is the value of the overlap, determined according to table 1, mm

When installing a casing made of a single sheet, the length of the casing sheet is determined by the formula

L = πD + N

where D is the outer diameter of the installed pipe insulation, mm;

N is the value of the overlap, determined according to table 1, mm

The width of the sheet of the casing of the connecting part is determined individually for each type of part.

The casing must be free of mechanical damage (dents, scratches to the metal), without gaps in the zinc coating.

The technical result of the invention is the provision of installation of thermal insulation of pipes and fittings of technological pipelines for above-ground and underground installation in the field, including difficult climatic conditions, and ensuring the preservation of the temperature of the pumped raw materials.

The invention allows to improve the installation technology of thermal insulation on process pipelines, which, in turn, reduces the cost of its installation and increases productivity.

Claims (7)

1. The method of installation of thermal insulation of technological pipelines, including the installation of composite shells as a coating on pipes and connecting parts, fastening them with bandages and protecting the joint seams, characterized in that foamed rubber in the form of tubes or rolls is used as thermal insulation of pipes and parts of technological pipelines, which is installed in several layers depending on the required thickness of the thermal insulation, while segments or sections, seams are used for thermal insulation of the connecting parts thermal insulation is glued with glue, and a galvanized steel casing is used as a protective sheath, while the casing is fixed using self-tapping screws. 2. The method according to claim 1, characterized in that before installing the insulation the surface of the pipeline is dried, cleaned of dirt, dust, ice, moisture and other contaminants. 3. The method according to claim 1, characterized in that the segments of foamed rubber can be in the form of tubes for pipes and fittings with a diameter of less than 159 mm, in the form of rolls (sheets) for pipes and fittings with a diameter of more than 159 mm. 4. The method according to claim 1, characterized in that the foamed rubber in the form of rolls (sheets) can be applied to the process pipe in the second and third layer, depending on the estimated thickness of the thermal insulation. 5. The method according to claim 1, characterized in that during the installation of thermal insulation all joints of composite shells of foamed rubber are glued with glue, the edges are glued to the pipe (connecting part) and to the thermal insulation of the previous section of the insulated pipeline. 6. The method according to claim 1, characterized in that a galvanized steel casing or two halves of a galvanized iron sheet is applied to the foam rubber insulation, while the edges of the upper half must be superimposed over the edges of the lower half. 7. The method according to claim 1, characterized in that for fastening the casing, self-tapping screws made of stainless steel are used.

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