GB2094929A - Device for introducing lining compositions and pipeline pigs into pipelines - Google Patents

Abstract

A device for introducing lining compositions comprises a composition container (1) connectable with the pipeline (14) and provided with a lower outlet opening (11) tightly connectable to a charging opening of the pipeline, an upper charging opening (2) tightly closable by a lid (7), and a compressed-air connection piece (9) arranged in the lid. A bag (12, Fig. 4 not shown) is located adjacent the inner wall of the container (1) and is open to the outlet opening (11) and to the charging opening (2). A pipeline pig (20, Fig. 6 not shown) on a draw cable may be introduced. <IMAGE>

Description

SPECIFICATION Device for introducing lining compositions and pipeline pigs into pipelines The invention relaxes to a device for introducing lining compositions and pipeline pigs into pipelines, the device comprising a composition vessel which is connectible with the pipeline.

It is known to line pipelines with an internal coating consisting of a hardening plastic composition. For this purpose there are preferably used synthetic resin compositions, for example on the basis of epoxy resin and bitumen. This method is used especially in earth-laid pipelines, especially in the case of steel and cast iron pipes. The method is used especially in public gas supply mains and water supply mains in order to seal off and put into order earth-laid defective or leaky pipelines with corrosion damage, leaky junctions and thn like and it is even possible for already existing holes in the pipe wall to be filled and durably sealed. In this way the necessity is avoided of blocking streets, tearing up the road surface at high expense, excavating ditches, laying a completely new pipeline and then repairing the road surface again.

The method is carried out in a manner in which a trench is excavated at the beginning and at the end of the pipeline run to be worked, and a pipe piece is taken out of the exposed pipeline. After the requisite preliminary work, for example cleaning of the pipeline, firstly a draw cable for a device called a pipeline pig is drawn through the pipeline, and the pig is secured to its end. Then the requisite quantity of plastic composition is charged into the same end of the pipeline, and after that the pig is introduced into the pipeline and drawn with the draw cable through the pipeline, in which operation the pig distributes the composition over the circumference and the length of the pipeline, presses it against the internal wall of the pipeline, produces the desired wall thickness of the coating and smooths the surface of the lining.

Here it is known to introduce the plastic composition into the pipeline by means of a pump or worm, in which case for example a flexible pipe connected to the pump or worm is firstly pushed far enough, according to the quantity of composition to be introduced, into the pipeline and can be drawn step by step out of the pipeline during the charging of the composition. However such devices are suitable only for compositions which are water-soluble before hardening, so that immediately after use the devices can be completely cleaned again by careful rinsing out with water. However these devices are completely useful for the above-mentioned non-water-soluble synthetic resin compositions which will be used for preference on account of their manifold advantageous properties.For such compositions therefore devices have been used which consist of a cylindrical composition container with a tapered outlet which is connected with the pipeline. After the charging of the composition a piston is inserted into the composition container and actuated by means of a presser device, for example a spindle, whereby the composition is forced by the piston out of the container into the pipeline. These devices too require immediate extensive, time-consuming and costly cleaning work after use, in order carefully to clean the piston, the cylinder wall and the tapered outlet before the composition hardens. The reason is that hardening composition residues which enter the pipeline with the plastic composition the next time the device is used can cause material defects in the lining to be produced.By way of example even very small composition hardened residues drawn through the pipeline by the pig can cause scratches in a thin-walled, still plastic lining, which is frequently only a few millimetres thick, which scratches then form open, uncoated areas of the pipe wall in the lining.

The invention is based firstly upon the problem of eliminating the above-mentioned dangers and drawbacks and of producing a device for introducing lining compositions which renders possible rapid, trouble-free and absolutely reliable cleaning after use.

This problem is solved by the device as characterised in Claim 1.

By way of example, when a pipeline of 150 m length has to be lined, the necessary quantity of composition to be introduced for this purpose can fill the end of the pipeline over a length of 20 m, so that for the introduction of the composition into the pipeline a correspondingly high pressure is necessary and the opening of the pipeline end must be closed. For this purpose upon the end of the pipeline there was fitted a securing device, for example a clamp ring or a pipe clamp, for a lid which is pressed against the opening of the pipeline and tightly closes the latter. The lid has an introduction opening with which the composition container is connected. Moreover the lid must be provided with a bore through which the draw cable can be conducted out of the pipeline to the exterior.This device has the disadvantage that the bore must be provided with a stuffing box to seal off the draw cable. The device further possesses the disadvantage that the stuffing box must be detached so that the lid can be drawn over the draw cable and removed before the pig is attached to the draw cable and introduced into the pipeline.

Then the further disadvantage arises that the pig is guided exactly centrally in the pipeline and can produce an exact lining only after complete introduction into the pipeline.

The invention is therefore further based upon the problem of eliminating the above-stated drawbacks and disadvantages and of providing a device which renders it possible to introduce the pipeline pig without trouble so exactly into the pipeline that from the outset the pig is drawn exactly coaxially and rectilinearly through the pipeline and that right from the opening of the pipeline onwards a satisfactory lining of the pipeline is guaranteed with uniform wall thickness all round.

This problem is solved by the further development of the device according to the invention with a charging sluice as characterised in Claim 3.

These and further features of the device according to the invention will be described below with reference to the didwing, in which an example of embodiment is illustrated and wherein: Figure 1 shows a composition container in lateral elevation, Figure 2 shows the detail II from Figure 1 on an enlarged scale, Figure 3 shows a plan view of the composition container according to Figure 1, Figure 4 shows a bag for the composition container according to Figure 1, in lateral elevation, Figure 5 shows a charging sluice in lateral elevation, Figure 6 shows the composition container according to Figure 1 in elevation and in connection with the charging sluice according to Figure 5, in longitudinal section.

The composition container 1 of the device (Figures 1 to 3) possesses an upper charging opening 2 with a flange 3 which is provided with bores 4 distributed over the circumference, into which round bolts 5 are inserted and welded. After charging of the composition into the composition container 1 the charging opening 2 is tightly closable by means of a lid 7 which rests on the flange 3 and is provided with bores 8 which engage over the bolts 5. The ends of the bolts 5 protruding from the lid 7 are provided with slots 6 into which there are inserted wedges 10 resting on the lid 7, which can be hammered firmly into the slots 6 and hammered out of the slots 6 again, so that the lid 7 can rapidly and without trouble be secured absolutely firmly and tightly on the composition container 1 and the charging opening 2 can be reopened equally rapidly and without trouble.In the lid 7 a compressed-air connection piece 9 is arranged which opens into the interior of the container 1 and to which for example a compressor can be connected by means of a compressed-air hose. The composition container 1 possesses a lower outlet opening 1 1 with which the container 1 can be connected, in the manner described in greater detail below, directly and in sealed manner to an entry opening of the pipeline.

The interior of the container 1 comprises an inserted bag 12 (Figure 4), the dimensions and forms of which are so selected that it rests on the inner wall of the container 1 and can be supported against this wall. At its upper and lower ends the bag 12 is open to the outlet opening 1 1 and to the charging opening 2. The bag 12 can consist of a sufficiently stout paper or another suitable material. After the charging of the lining composition into the composition container 1 and closure of the lid 7, compressed air is introduced through the compressed-air connection piece 9 into the interior of the container 1 above the composition, and forces the composition downwards through the outlet opening 11 directly into the pipeline.Due to this formation of the device, dispensing with a piston, the use of the bag 12 is possible so that the composition does not come into contact with the internal wall of the container 1. After the device has been used therefore only the lid 7 is opened, the ban 12 with the composition residues adhering to it is taken out and destroyed, and later a new bag is inserted.

Cleaning of a small area needs to be effected only in the region of the outlet opening 11.

The composition container 1 can be connected directly to the pipeline for example in that a pipe bend is attached to the end of the pipeline and the container 1 is fitted on this bend. This is superfluous due to the further development of the device as illustrated in Figures 5 and 6, with a charging sluice 13. The tubular charging sluice 13 possesses an external diameter which corresponds to the external diameter of the pipeline 14 at least so nearly that the sluice 13 can be attached conveniently and without great expenditure of labour to the end of the pipeline 14 by means of a pipe strap 15. The strap 15 clamps around the pipeline 14 and the sluice 13 so firmly that these are connected with one another by the strap so as to be fast to traction. At the same time the joint between sluice 13 and pipeline 14 is sealed by the strap 1 5.Furthermore the pipe strap 15 is so long in the axial direction that the sluice 13 is automatically oriented exactly by the strap 15 and proceeds exactly coaxially with the pipeline 14. At its rear end the sluice 13 is tightly closable by means of a lid 16 which is provided on its circumference with hooks 17. The sluice 13 is provided with simple eccentric catches 18 which are used for example in packaging crates and the like and the rings or tags 1 9 of which are attached to the hooks 17. The charging sluice 13 is so long that it can accommodate a pipeline pig 20 in its rear part, which pig is connected at its forward end through a swivel joint 21 with the draw cable 22 and possesses guide bodies 23 for its central guidance in the pipeline and spreader bodies 24 for the spreading and smoothing of the lining composition, which bodies are secured on a rod 25.The sluice 13 possesses an internal diameter corresponding to the clear internal cross-section of the pipeline 14. In front of the pipeline pig 20 the sluice 13 is provided with the entering charging opening 26 to which the composition container 1 is connected. In this way the device makes it possible for the pig 20 to be secured to the draw cable 22 and inserted into the charging sluice 13 even before the lining composition is introduced into the pipeline 14, so that the draw cable 22 does not have to be guided out through a stuffing box. In the introduction of the composition into the pipeline 14 the pig 20 and the lid 16 close off the sluice to the rear, while the lid 16 at the same time has the effect that the pig 20 cannot be forced out of the sluice 13. Since the sluice 13 is oriented exactly coaxially with the pipeline 14, and since the pig 20 is oriented exactly centrally in the sluice 13, the device achieves the object that the pig is introduced into the pipeline exactly rectilinearly and centrally from the outset. The arrangement of the charging opening 26 on the sluice 13 further achieves the object that the spreading of the lining composition already commences in the sluice 13, so that the pipeline 14 is provided with an exact and defect-free inner coating which already begins at its end.

In a further development of the invention the outlet opening 1 1 of the composition container 1 is formed as an externally threaded pipe connection piece (Figure 1) and the charging opening 26 of the sluice 13 is formed as an internally threaded pipe connection piece (Figure 5) into which the pipe connection piece of the composition container 1 can be screwed, the threading being formed as knurled or round threading. It has been found that such a threading comes into engagement in the fitting of the composition container 1 upon the sluice 13 even if it is soiled by hardened residues of composition, and cleans itself in the screwing-in of the threaded connections.If on the other hand an ordinary threading with pointed teeth and tooth grooves is soiled by contact with gloves to which composition residues adhere, which frequently is unavoidable, the hardening composition residues become so firmly deposited in the threading that the latter does not engage when the composition container 1 and charging sluice 13 are being screwed together, and can also be cleaned only with maximum effort.

It has been found that even relatively large quantities of compound for lining lengthy pipeline sections can well be introduced into the pipeline if, in addition to the pressure generated in the composition container 1, a negative pressure is generated in the pipeline by a suction device at the other end of the pipeline 14. In order to prevent the pipeline pig 20 from being sucked by such a negative pressure out of the sluice 13 and into the pipeline 14 before the operation of charging the composition is terminated, in further development of the device in accordance with the invention a detachable fastening for the pig 20 is arranged on the lid 1 6 of the sluice 13 (Figure 6).

The fastening consists of a smooth, tubular sleeve which is guided in sealing manner through a narrow bore of the lid 1 6. The one internally threaded end of the sleeve 27 is screwed on to the externally threaded end of the axial rod 25 of the pig 20. A nut 28 is screwed on to the other externally threaded end of the sleeve 27 which protrudes from the lid 16. After the charging of the lining composition into the pipeline 14 the fastening of the pig 20 is released by unscrewing of the sleeve 27 from the rod 25, and the sluice 13 is opened by removal of the lid 16, so that when the pig 20 is pulled through the pipeline 14 air can flow in after it and no negative pressure occurs behind the pig.

Claims (5)

1. A device for introducing lining compositions and a pipeline pig into a pipeline, comprising a composition container connectible with the pipeline and provided with a lower outlet opening tightly connectible to a charging opening of the pipeline, an upper charging opening tightly closable by a lid means, and a compressed-air connection piece arranged in the lid means to open into the interior of the container, and a bag located adjacent the inner wall of the container and open to the outlet opening and to the charging opening.

2. A device as claimed in Claim 1, wherein the outlet opening is formed as an externally threaded pipe connection piece which is screwable into a charging opening formed by an internally threaded pipe connection piece, the threading being formed as knurled or round threading.

3. A device as claimed in either Claim 1 or 2, wherein a tubular charging sluice, to accommodate at a rearward end zone thereof the pig, possesses an internal diameter corresponding to the clear internal cross-section of the pipeline, is connectible by its forward end tightly and coaxially to the pipeline, is provided with the charging opening located forwardly of the pig and is tightly closable at its rear end by means of a lid.

4. A device as claimed in Claim 3, wherein a detachable fastening for the pig is arranged on the lid.

5. A device substantially described herein with reference to the accompanying drawings.