The object of the invention is a method as defined in the preamble of claim 1.
The object of the invention is also an apparatus according to claim 7.
Bushing joints are generally used for connecting pipes, more particularly plastic pipes, together end-on-end. The point of connection is placed into the bushing, i.e. into the sleeve part, such that the ends of the pipe parts to be connected together are inside the bushing and the bushing is thus around the point of connection extending some distance in the longitudinal direction of the pipes from the point of connection in both directions. The bushing part is provided with thermal resistors or corresponding, in which case when forming the joint electric current is conducted to the resistors, in which case the resistors heat up and a joint forms between the sleeve part and the pipe parts. The type of joint described has the problem, particularly when applied in the joints of the transfer pipings of pneumatic waste-transporting systems, that a gap or sill that is detrimental to the transportation of material can remain between the pipe parts to be connected. In prior-art solutions the bushing can contain a countersurface against which the pipe parts to be connected together should be placed, but in practical installation conditions installation errors that result in an unsatisfactory joint can remain in the placement of the pipes into the bushing. Thermoplastic pipe joints of the type described above are described e.g. in the publications U.S. Pat. No. 2,739,829, U.S. Pat. No. 4,530,521 and U.S. Pat. No. 4,906,313. The verification of the tightness of a joint and its pressure testing, especially the verification of the tightness of pneumatic waste-conveying pipings and the pressure testing of their points of connection, is challenging in cases where the pipelines are long. Owing to long pipe series and typically rather large pipe diameters, pipe diameters typically being 200-500 mm, the pressure testing of pipings for their complete length is time consuming owing to the large volume of the pipelines. In addition, a lot of the liquid or gas to be used in pressure testing is consumed, the pumping of which liquid or gas consumes a lot of energy.
The aim of this invention is to achieve a completely new type of solution for the pressure testing of the joints of the transfer piping of a pneumatic waste-conveying system, by means of which the problems of prior-art solutions can be avoided. One important aim is to achieve a method and an apparatus applicable to testing and pressure testing the tightness of the transfer pipings of pneumatic pipe transporting systems for waste, which is suited to different pipe joints.
The method according to the invention is mainly characterized in that in the method a device is taken inside the piping, which device comprises a first wall part, which comprises first sealing means, and a second wall part, which comprises second sealing means, in which case the pipe section to be tested, more particularly the point of connection, remains between the first wall part and the second wall part, in which case the sealing means of the first wall part are brought to be tighter to the inside surface of the pipe and the sealing means of the second wall part are brought to be tighter to the inside surface of the pipe and pressure medium is brought into the chamber space bounded by the first wall part and the second wall part as well as by the inside surface of the pipe section, and the pressure or a change of pressure is measured or a possible sealing defect of the pipe section is otherwise indicated.
The method according to the invention is also characterized by what is stated in claims 2-6.
The apparatus according to the invention is mainly characterized by what is disclosed in claim 7.
The apparatus according to the invention is also characterized by what is disclosed in claims 8-12.
The solution according to the invention has a number of important advantages. With the method and apparatus according to the invention it is possible to quickly and easily pressure test and test the tightness of sections, more particularly the points of connection, of piping.
Consumption of the pressure medium needed is minimal in relation to if the whole pipeline were filled with pressure medium. By using a pressure-medium operated, preferably flexible, bellows means as a sealing means for the first wall part and/or the second wall part, which bellows means when pressurized expands from a first position to a second position in the radial direction and becomes tighter to the inner surface of the pipe, an inexpensive and extremely effective solution is achieved for separating and sealing a pipe section to be tested or pressure tested. By using pressure-medium channels arranged in the body of the device for bringing the pressure medium to the bellows means that function as sealing means, into the chambers of said bellows means, a well-protected and extremely effective solution is achieved for moving the sealing means. By additionally arranging hose means, with which pressure medium is brought to the device, a transfer solution for pressure medium is achieved that is extremely well suited to installation conditions and testing conditions. By using supporting walls, which are at a distance from each other and are in the transverse direction with respect to the pipe part, in connection with the wall parts, into the space between which supporting walls bellows means functioning as sealing means are arranged, a solution is achieved that protects the sealing means very well, especially when putting the device inside the pipe and when taking it out of the pipe. By using a sleeve part as a bushing in the joint and by using the inspection aperture arranged in said sleeve part, an extremely effective solution is achieved for inspecting the quality of a pipe joint in connection with its formation. Additionally, the aperture can be used as a machining point in forming the aperture needed for the installation of various sensors. A fixing point, such as threads, can be conveniently arranged in connection with the aperture for the fixing of various sensors and measuring devices. The aperture of the sleeve part can be further utilized e.g. for the internal visual inspection of a pipe when an aperture is formed from the aperture of the sleeve part through the wall of the pipe parts. In addition, the aperture of the sleeve part can easily be provided with a plug comprising a counterthread, which is suited to the threads of the protrusion part of the aperture of the sleeve part.
In the following, the invention will be described in more detail by the aid of an example with reference to the attached drawing, wherein
The inspection aperture 8 can be used most preferably in the phase of forming the pipe joint to ensure the correct positioning of the pipe parts 2, 3 to be connected together, for forming a joint of good quality. From the inspection aperture 8 it can easily be detected whether there is an undesirable gap between the pipes, incorrect positioning or whether the pipes are not properly against each other. Thus by means of the invention the correctness of the position of the pipes to be connected can be verified before forming a joint.
From the aperture 8 of the sleeve part of
In
In
The device according to the embodiment of the invention comprises pressure-medium operated sealing means 31, 33 in the first wall part 21 and in the second wall part 22. A first pressure-medium pathway 25 from the pipe means or hose means 28 to the sealing means 31 of the first wall 21 is formed in the body 24 of the device. According to one embodiment the sealing means 31 of the first wall is a flexible bellows means, when conducting pressure medium into the chamber 32 of which the diameter of the bellows means increases and it becomes tighter against the inside surface 14 of the pipe part 2. Correspondingly, a second pressure-medium pathway 26 from the pipe means or hose means 30 to the sealing means 33 of the second wall 22 is formed in the body 24 of the device. The sealing means 33 of the second wall is a flexible bellows means, when conducting pressure medium into the chamber 34 of which the diameter of the bellows means increases and it becomes tighter against the inside surface 15 of the pipe part 3.
The structure of the sealing means 31, 33 is such that they return from the second position into the first position when the pressure medium is removed from the chamber 32, 34.
In connection with the first wall part 21 at a distance from each other are supporting walls 35, 36 in the transverse direction of the pipe part, into the space between which supporting walls a bellows means is arranged. The diameter of the supporting walls 35, 36 is to some extent smaller than the internal diameter of the pipe part 2. The bellows means in the first position, in the retracted position, is to some extent closer in the radial direction than the outer edges of the supporting walls to the body 24 of the device. In this case the outer edges of the supporting walls 35, 36 extend to closer to the inside surface of the pipe than bellows means. Here, in the first position (
In connection with the second wall part 22 at a distance from each other are supporting walls 37, 38 in the transverse direction of the pipe part, into the space between which supporting walls a bellows means is arranged. The diameter of the supporting walls 37, 38 is to some extent smaller than the internal diameter of the pipe part 3. The bellows means in the first position, in the retracted position, is to some extent closer in the radial direction than the outer edges of the supporting walls to the body 24 of the device. In this case the outer edges of the supporting walls 37, 38 extend to closer to the inside surface of the pipe than bellows means. Here, in the first position (
In
According to the embodiment of the invention, a third pathway for medium is arranged in the body 24 of the device, which pathway leads from the input pipe or input hose 29 to the space 23 between the first wall part 21 and the second wall part 22.
In the embodiment of
The pipe joint according to the invention, and the pressure-testing method and pressure-testing device for it, are very well suited for use in connection with the joints of the transfer piping of pneumatic pipe transport systems for waste. The pipe sizes can be rather large in diameter, e.g. typically 200-500 mm.
The object of the invention is thus a method for testing and/or for pressure testing the tightness of the joints of the transfer piping of a pneumatic pipe transport system for waste, in which method the pipe section to be tested is separated inside the pipe from the other piping and pressure medium is conducted into the section, and leaks and/or the pressure of the pressure medium are monitored on the section of pipe to be tested. In the method a device is taken inside the piping, which device comprises a first wall part 21, which comprises first sealing means 31, and a second wall part 22, which comprises second sealing means 33, in which case the pipe section to be tested, more particularly the point of connection, remains between the first wall part 21 and the second wall part 22, in which case the sealing means 31 of the first wall part are brought to be tighter to the inside surface 14 of the pipe and the sealing means 33 of the second wall part 22 are brought to be tighter to the inside surface 15 of the pipe and pressure medium is brought into the chamber space 23 bounded by the first wall part 21 and the second wall part 22 as well as by the inside surface of the pipe section, and the pressure or a change of pressure is measured or a possible sealing defect of the pipe section is otherwise indicated.
According to one embodiment the sealing means 31, 33 of the first wall part and/or of the second wall part is a pressure-medium operated bellows means, which when pressurized expands from a first position to a second position in the radial direction and becomes tighter to the inner surface of the pipe.
According to one embodiment pressure medium is brought into the chamber space 23 from an aperture 12 formed in the wall of the pipe
According to one embodiment pressure medium is brought into the chamber space 23 via a pressure-medium channel 27 arranged in the body 24 of the device.
According to one embodiment pressure medium is brought into the bellows means that function as sealing means 31, 33 via pressure-medium channels 28, 29 arranged in the body 24 of the device.
According to one embodiment the pipe joint to be tested is formed by using a sleeve part 4, which comprises a chamber space, into which the opposing butt ends 5, 6 of the pipe parts 2, 3 to be connected together are placed essentially against each other such that the sleeve part 4 extends a distance from the point of connection of the pipe parts 2,3 to be connected together on top of both pipe parts 2, 3, which sleeve part 4 comprises heating means 7, such as resistance wires 7, as a consequence of the heating of which resistance wires a joint forms between the sleeve part 4 and the pipe parts 2, 3, and that an inspection aperture 8 is formed in the sleeve part 4 through the wall of the sleeve part from the outside to the inside at point in which the positioning of the butt end surfaces 5, 6 placed essentially against each other of the pipe parts 2, 3 to be connected together can be verified and that the inspection aperture 8 is fitted for the purpose of a pressure-medium hose or a measuring sensor, such as a temperature sensor or a pressure measuring sensor.
The object of the invention is also an apparatus for testing and/or for pressure testing the tightness of the joints of the transfer piping of a pneumatic pipe transport system for waste. The device is fitted to be inserted into and extracted from the piping, which device comprises a first wall part 21, which comprises first sealing means 31, and a second wall part 22, which comprises second sealing means 33, in which case the pipe section to be tested, more particularly the point of connection, remains between the first wall part 21 and the second wall part 22, in which case the device comprises means for bringing the sealing means 31 of the first wall part to be tighter to the inside surface 14 of the pipe and means for bringing the sealing means 33 of the second wall part 22 to be tighter to the inside surface 15 of the pipe, and means for bringing pressure medium into the chamber space 23 bounded by the first wall part 21 and the second wall part 22 as well as by the inside surface of the pipe section, and means for measuring the pressure or a change in pressure of the chamber space 23, or for indicating in some other manner a possible sealing defect of the pipe section.
According to one embodiment the sealing means 31, 33 of the first wall part 21 and/or of the second wall part 22 is a pressure-medium operated bellows means, which when pressurized expands from a first position to a second position in the radial direction and becomes tighter to the inner surface of the pipe.
According to one embodiment the device comprises pressure-medium channels 28, 29 arranged in the body 24 of the device for bringing pressure medium to the bellows means that function as sealing means 31, 33, into the chambers 32, 34 of said bellows means.
According to one embodiment a pressure-medium channel 27 is arranged in the body 24 of the device for bringing pressure medium into the chamber space 23.
According to one embodiment pressure medium is brought into the chamber space 23 from an aperture 12 formed in the wall of the pipe.
According to one embodiment in connection with the wall part 21, 22 at a distance from each other are supporting walls 35, 36; 37, 38 in the transverse direction of the pipe part, into the space between which supporting walls a bellows means functioning as a sealing means 31, 33 is arranged.
It is obvious to the person skilled in the art that the invention is not limited to the embodiments presented above, but that it can be varied within the scope of the claims presented below. The characteristic features possibly presented in the description in conjunction with other characteristic features can, if necessary, also be used separately to each other.
Number | Date | Country | Kind |
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20106145 | Nov 2010 | FI | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/FI11/50844 | 9/30/2011 | WO | 00 | 4/30/2013 |