WO1986006148A1

WO1986006148A1 - Divisible watertight protective covering for insulation on pipes and similar

Info

Publication number: WO1986006148A1
Application number: PCT/SE1986/000176
Authority: WO
Inventors: Alvar Wedin
Original assignee: Alvar Wedin
Priority date: 1985-04-16
Filing date: 1986-04-16
Publication date: 1986-10-23
Also published as: AU5771986A; SE8501846D0; SE8501846L

Abstract

Removable watertight protective covering (1) for insulation on a pipe or suchlike, consisting of parts that can be removed and refitted and made of watertight and gastight material, preferably metal, and designed with longitudinal joints (13) and circumferential joints (14), sealed to prevent passage of water. The longitudinal joints are formed as Tee-shaped flanges (6a, 6b) and fit into one another to secure their positions reliably against a seal (12) fixed in one arm of each Tee-shaped flange. The Tee-shaped flanges are held together with clips (7). The ends of the parts of the protective covering are formed with Vee-shaped radial flanges (5a and 5b) that fit one over the other to provide radial and axial attachment of adjacent parts of protective covering and permit expansion movement. The circumferential joints are sealed with circumferential sealing strips (10) which are attached to a tensioning strip (8) with an over-centre catch (9) which, when tensioned and locked, seals the circumferential joint (14). The area between longitudinal and circumferential joints is sealed by a special sealing sheet (11) which is secured by the circumferential sealing strip (10) and a clip (7) on the end of the longitudinal joint.

Description

DIVISIBLE WATERTIGHT PROTECTIVE CC-VEJO G FOR INSULATION ON PIPES

AND SIMILAR j;

This invention is in respect of a removable watertight protective covering for insulation on pipework systems and simi-

5 lar, for which the protective covering consists of parts made of watertight and mechanically strong material that are joined by longitudinal and circumferential cross joints and are sealed against penetration by water and permit expansion movement while retaining their tightness. The protective covering may be removed

10 and refitted.

In the case of pipes placed outdoors and capable of being subjected to rain or low temperatures, and pipes buried under¬ ground and in culverts that may became filled with water, or in otherwise moist or corrosive conditions, it is important that the

-^■-* protective covering be watertight.

Many different systems for fitting and surfacing pipe insula¬ tion are known, but most such protective coverings for pipe insulation are either not watertight or cannot be opened for inspection or be removed without being destroyed. Water that

20 enters a leaky protective covering impairs the insulation, resul¬ ting in heat losses and serious corrosion attack of the insulated pipes, thereby iπplying a major risk for accidents in the event of the pipe containing an inflaπmable or toxic liquid or gas.

Many of the surfacing and protective coverings for insulated

25 pipes used in industry, ships, oil rigs and in other fields, involve the use of materials such as aluminium or galvanized steel sheet, in which the protective covering is produced manually and seam joints are formed, overlapped and held together using Pop rivets, which do not permit expansion movement of the protective

30 covering and which result in certain joints failing and cpening. Without sealing ccmpσund these joints failing and opening. Without sealing compound these joints leak over their entire length. Because water enters the lekaing joints, there is a risk of corrosion of the insulated pipes so that inspection must be

35 carried out at certain intervals. Protective coverings of this type are destroyed when they are opened for inspection of the insulated pipe and the protective covering must therefore be discarded. Another type of protective covering that is used involves overlapping the joints by about 50 mm and holding the ends together with circumferential steel strips which do not provide watertight joints.

It is a wish and demand frcm industry and other users that protective coverings for insulation pipes and suchlike be water¬ tight and removable for inspection and leak detection frαn the pipe and for connection branches or similar. The protective covering shall also be mechanically strong and retain its tight¬ ness against penetration by water even if it becomes deformed and shall also be fire-resistant and resistant to decemposition as a result of any leakage frαn the pipe.

The problem that formed the basis of this invention was to obtain a protective covering for insulation on pipework systems and similar, where the protective covering in the fitted state is watertight and capable of being removed and refitted without any significant part of it being damaged, and it should be resistant and durable against decemposition resulting from any leakage from the pipe and should be mechanically durable against temporary deformation, e.g. as a result of anyone walking on the protective covering. The protective covering should be easy to fit and remove and be designed so that it cannot be incorrectly fitted and should be capable of being fitted without any or very few tools and the manyfacturing cost should be lew.

Characteristic of this invention is that the protective covering is made in two halves, in which the halves divided by longitudinal joints are formed to a Tee-shaped flange, one half of the flange fitting into the other half flange, the bottcm of which contains an elastic seal fitted along the entire length of the flange. The flanges are held together by suitable means, such as clips, so that the two joined halves of the protective covering together form a unit with two sealed longitudinal joints. The shape of the flange is important for its sealing func¬ tion, mechanical strength and stability, and for the joining clips which, using a mounting bar, are formed around the flanges to exert suitable pressure for sealing against the seal. Because the area of the sealing part of the flange against the entire lengt of the seal is small, only a small pressure is required frαn the joining clips to achieve a reliable seal. The two protective covering halves joined with clips form a unit. The circumferential transverse joints are formed to Vee-shaped flanges, so that the flange of one part of the protective sheath fits into the flange of the other part of the protecive sheath forming a joint that permits expansion movement while keeping the parts of the protec¬ tive covering together securely. The transverse joints are sealed by circumferential sealing strips of suitable elastic material which, by means of an over-centre catch, is pressed against the surface of the covering sheath at the same time as the ends of the sealing strip are pressed together and form a seal. In parts at which longitudinal joints meet a transverse joint, the flange of the longitudinal joint is cut short at an angle and sealed with a suitable sealing device, such as sheet steel, formed to fit the end of the longitudinal joint and with self adhesive sealing compound applied to its underside. One end of this sheet to which sealing compound has been applied is attached by a clip on the end of the longitudinal joint and the other end is fastened by the circumferential sealing strip, which presses it, with the sheet to which sealing compound has been applied, against the covering sheath, in doing which the sealing ccmpound is pressed out and seals beween the edges of the sheet and the sealing strip. Further characteristics and advantages of the invention will be made clear by the following detailed description which will refer to the appended drawings.

On the drawings:

Figure 1 shews a small section of an insulated pipework system in which the insulation is enclosed in a covering sheath in accordance with the invention.

Figure 2 shews an enlarged cross section along line II-II in Figure 1, shewing the longitudinal joint. Figure 3 shews an enlarged illustration of the transverse joint shown in Figure 1 and a perspective of a clip and a special sealing device for the area between a longitudinal joint and a transverse one. Figures 1 and 2 shew a section of insulated pipework consis¬ ting of a longitudinal pipe, 3, and a 90 elbow, 4, which are welded together in the normal manner. The pipes are fitted with an insulation, 2, such as mineral wool insulation, and the insulation is enclosed in a protective covering, 1, with a sealing longitudi- nal joint, 13, and sealing circumferential joint, 14. The protec¬ tive covering is made in two halves, la and lb, of any suitable material that is inpenetrable by water, gas, etc and has suffi¬ cient mechanical strenth to be resistant to impact and being walked on, and which is preferably fire-resistant. The material of the protective covering is preferably metal, such as steel with a cotaing of aluminiuπt-zinc alloy, stainless steel, aluminium or similar, with a smooth and heat-reflecting surface.

As may be seen most clearly in Figure 2, the longitudinal edges of each of the covering halves, la and lb, is formed to a part of the Tee-shaped flange, 6a and 6b, so that the flange on one of the parts of the protective covering, 6b, fits into the flange of the other part of the protective covering, 6a, which, in the bottαn of the flange has a fitted elastic seal, 12, to provide a seal. The flanges are held togehter by clipes, 7, which are formed round the flanges, 6a and 6b, using a special mounting bar to exert a suitable pressure against the seal, 12, to provide a seal. The shape of the flanges is important for sealing, mechani¬ cal strength and stability and for the joining clips. Because the area of the sealing part of the flange against the seal is small, only a small pressure is required frcm the joining clips to achieve a reliable seal.

The circumferential transverse joint, 14, is formed to Wee-shaped flanges, 5a and 5b, in which one flange, 5b, fits into the other flange, 5a. The shape and fit of the flanges into one another permits expansion movement while holding the parts of the protective covering together securely. Transverse joints, 14, are sealed with circumferential sealing strips, 10, of suitable elastic material, such as foam rubber or similar with a smooth surface and are sufficintly wide to cover the Vee-shaped flanges, 5a and 5b, and a part of the skin of the protective covering, 1, on each side of the flanges. The thickness of the sealing strip may be about 5 mm and it is secured by an encompassing tensioning strip, 8, which preferably consists of metal shaped to fit outside the flanges of the circumferential joint. At each end of the tensioning strip, 8, there is an over- centre clip, 9, with which to tension the sealing strip, 10, to seal against the surface of the protective covering, 1, and lock the tensioning strip, thereby pressing the ends of the sealing strip together and fo ing a seal.

In the area where a longitudinal joint and a transverse joint meet, the flange of the longitudinal joint is cut short at an angle and sealed with a suitable sealing device, 11, such as sheet steel formed to fit the end of the longitudinal joint and fitted on its underside with self-adhesive sealing cc pc-und, 15. One end of this sheet, 11, fitted with sealing ccmpσund is secured by a clip, 7, on the end of the longitudinal joint and the other end is secured by the circumferential sealing strip, 10, which presses the sheet, 11, with the sealing ccmpσund, 15, against both the angled end of the longitudinal joint and forms a seal, and against the skin of the protective covering, so that the sealing ccmpσund, 15, is pressed out and seals between the edges of the sheet and the sealing strip.

The above description and the drawings only show one form of construction of the invention, but more constructions and modifi¬ cations may occur within the sccpe of the following patent claims.

Claims

STATEMENTUNDERARTICLE 19

The claims have been made broader. The invention can not only be used as a protective covering on an insulation on a pipe but also as a conventional tube for transport of air, grain or such as. The amendments are made within the disclosure in the inter¬ national application as filed. Principally only the words "protec¬ tive covering" are changed to "tube, for instance usable as a protective covering". This change does not have any impact on the drawing.

In the description the words "protective covering" on side 2, line 26, 27 and 32 shall be changed to "tube".

The introduction of the description also shall be changed inte accordance with the new main claim. The title of the invention may be changed to "Easily divisib¬ le removable tight tube, for instance useable as a protective covering for insulation on a pipe or suchlike".