Description

[0001] Cross-reference to related applications

[0002] The present invention claims priority to the patent application LU500410 filed in Luxembourg on 08 July 2021. The entire disclosure of the Luxembourg patent application LU500410 is thereby incorporated therein by reference.

[0003] Field of the invention

[0004] The present invention concerns compression fittings or press fittings. The pre sent invention also concerns a method of assembly of such press fittings.

[0005] Compression fittings, also called press fittings, which can connect tubes by com pression and deformation using one or two fitting sleeves, are well known in the field of tubing, piping and line system installations, for example for water, gas or heating.

[0006] Press fittings are used to connect pipes, in particular those made from plastic or composite metal-plastic. They are used to connect appropriately arranged sections of pipe, with their connecting pieces being inserted into the ends of the pipes to be connected, where they are then usually de-formed or crimped or pressed. They are fastened in certain fastening zones on the connection pieces by using so-called system compression tools that usually have interchangeable pressing jaws.

[0007] The tube, pipe, or conduit systems are assembled in several steps: first an end of the tube or pipe is inserted into a fitting, and then the fitting is crimped to guarantee good mechanical strength and a leak-tight installation. The compression is usually essentially a pressure on the fitting sleeve which causes the deformation or shaping of the fitting towards the pipe which is inserted into it. The pressure is usually applied to the fitting using a crimp ing tool with press jaws. These pressing jaws apply pressure to the fitting material in order to bring about an interaction with the surface of the pipe(s)/tube(s) to be connected, thus achieving a reliable connection and a reliable seal. In some cases, the crimping also involves a deformation of the tube or piping itself in order to provide an interaction between the tube and an inner part of the fitting.

[0008] One object of the present invention is to provide a press fitting having improved handling capacities during installation.

[0009] It is another object of the present invention to provide a secure connection of at least one tube or pipe, in particular part of a piping system for hot and cold-water installations inside buildings, for example as a multilayer or flexible piping system.

[00010] Summary of the invention

[00011] To this end, the present invention proposes a press fitting according to claim 1 and a method according to claim 16. Preferred embodiments are defined in the dependent claims.

[00012] According to the invention, the press fitting for the connection of a pipe end, comprises a main body with a fitting portion and a fitting support extending in an axial di rection from the fitting portion, and a compression and fixation assembly mounted to the fitting portion, the compression and fixation assembly and the fitting support defining a pipe insertion space for inserting a pipe end to be fixed on said fitting support. The compression and fixation assembly comprises a compression sleeve. The compression sleeve comprises a sleeve body in a form of an open ring. The open ring has two annular ends which are connected mutually through at least one crimping ear. The crimping ear projects radially outwardly from the sleeve body. The at least one crimping ear is deformable for fixing the pipe end to the fitting, preferably by deformation against the fitting support.

[00013] In one aspect the compression and fixation assembly comprises a fitting body mount, with a radial projection provided to the compression sleeve and cooperating with a sleeve fixation element of the fitting portion. The fitting body mount and the sleeve fixation element can cooperate so that the compression sleeve is axially fixedly maintained on the fitting support and is in an uncompressed state freely rotatable around said fitting support. This is very advantageous as the installation space may be reduced or in comers not easily reachable. This allows a good holding of the compression sleeve mounted to the fitting sup port, whilst allowing the rotation of the compression sleeve around said fitting support, which in turn allows a user rotating the compression sleeve before crimping to find an easy crimping position even in narrow corner of roof or reach partially hiding positions.

[00014] In one aspect, the compression and fixation assembly comprises a decoupling element provided between the sleeve body and the fitting body mount. A decoupling ele ment allows absorbing the constraints exerted on the compression sleeve during crimping, to avoid possible break of the compression sleeve or of the body fitting mount of the com pression sleeve resulting from the induced stress during crimping.

[00015] In one aspect, the sleeve fixation element is a slider for holding the radial pro jection of the fitting body mount, preferably the slider is circumferentially extending around the fitting support, more preferably forming a ring-shaped recess with a retainer.

[00016] In an alternative aspect, the compression and fixation assembly comprises a fix ation ring cooperating with the fitting support. The compression sleeve comprises a fitting body mount. The fixation ring holds the compression sleeve via the fitting body mount, pref erably in a freely rotatable manner.

[00017] The fixation ring can comprise a slider at one axial end for receiving the fitting body mount of the compression sleeve. In an uncompressed state of the compression sleeve the fitting body mount of the compression sleeve is received and held in a freely rotatable manner around the fixation ring. Preferably the slider is circumferentially extending around the fixation ring. The fixation ring may comprise a ring fixation mount at its other axial end mounted to the sleeve fixation element of the fitting portion. Optionally the ring fixation mount cooperates with the sleeve fixation element of the fitting portion in a freely rotatable manner. The fixation ring maintains the compression sleeve fixedly axially on the fitting support and in an uncompressed state of the compression sleeve freely rotatable around said fitting support. This allows a good holding of the compression sleeve mounted to the fitting support, whilst allowing at least when the compression sleeve is in an uncompressed state the rotation of the compression sleeve around said fitting support, which in turn allows a user rotating the compression sleeve before crimping to find an easy crimping position even in narrow comer of roof or reach partially hiding positions.

[00018] In one aspect the compression and fixation assembly, in particular the fitting body mount and/or the fixation ring has at least one panoramic window to monitor the cor rect insertion of the pipe.

[00019] In one aspect, the fitting portion is provided with a slider for holding a radial projection of the fitting body mount, preferably the slider is circumferentially extending around the fitting support, more preferably forming a ring-shaped recess with a retainer. This allows a good holding of the compression sleeve mounted to the fitting support, whilst al lowing the rotation of the compression sleeve around said fitting support, which in turn al lows a user rotating the compression sleeve before crimping to find an easy crimping posi tion even in narrow corner of roof or reach partially hiding positions.

[00020] The circumferential slider is a non limiting example of the fixation means be tween the fitting portion and the compression sleeve, or between the fixation ring and the compression sleeve. Any other cooperating fixation is possible, as long as the compression sleeve is freely rotatable, in an uncompressed state.

[00021] In one aspect, the fitting body mount has at least one panoramic window to mon itor the correct insertion of the pipe. This ensures that the correct connection of the tube to the press fitting for crimping, and hence of the crimping.

[00022] In one aspect, the compression sleeve comprises two crimping ears spaced apart in the axial direction. Providing two crimping ears in series provide a good mechanical re sistance to maintain the pipe under operational condition. The number of crimping ears is not limiting the invention, and only one crimping ear, or more than two crimping ears can be provided.

[00023] In a further aspect, the compression sleeve is provided with an anti-ovalisation tongue designed to distribute the crimping force around the pipe and the main body. The anti-ovalisation tongue can be an annular projection extending from one of the annular end towards the other annular end, preferably the anti-ovalisation tongue being positioned adjacent the at least one crimping ear and/or bridges the distance between adjacent crimping ears. The anti-ovalisation tongue limits the ovalisation of the main body during the crimping process and helps preventing the pipe flow into the crimping ears. This helps ensuring a full jointing between the pipe and the body and avoiding leakage.

[00024] The anti-ovalisation tongue can be designed to move into an anti-ovalisation channel of the sleeve body during crimping process.

[00025] The anti-ovalisation tongue and the anti-ovalisation channel form a crimping in dicator, in particular wherein the anti-ovalisation tongue is not visible after closing of the at least one crimping ear. Again, this helps ensuring that the crimping is correctly done, and hence a reliable connection between the tube and the press fitting.

[00026] The anti-ovalisation tongue can have the same thickness as the compression sleeve. This helps guaranteeing a good repartition of force.

[00027] The width of the anti-ovalisation tongue can vary from 0.5 to 1.5 the width of the crimping ear(s), and the anti-ovalisation tongue can have a length in the range of 0.5 to 0.75 of the length of crimping ear.

[00028] In one aspect, the press fitting is preassembled. Advantageously, the press fitting is ready for use, thereby minimizing the installation steps for the user, in particular in comers which are not easy to reach for the user.

[00029] In one aspect, the compression sleeve is manufactured from a deformed metal sheet, in particular wherein the metal sheet is cut and deformed, the crimping ear(s) being formed by bending a tab around another also bent end portion of metal sheet, preferably connected using latch and hole arrangement(s). The compression sleeve, including the anti- ovalisation tongue and the fitting body mount, can be made from a single deformed metal sheet. Alternately, the compression sleeve, including the anti-ovalisation tongue, can be made from a single deformed metal sheet. [00030] The pipe or tube can be mono material and made of thermoplastic materials in cluding but not limited to PE, PB, PEX, PERT, PER ... or Composite (multi material tube structure) with different layers of functional materials (PEX, PERT, PVDF, Aluminium...).

[00031] The material for the fitting body can be metal (brass, Stainless steel....) or Ther moplastic (PVC, PPSU, PVDF, PPS, that can also be reinforced with fibre glass reinforce ment). The fitting body may also comprise several materials, e.g. the sleeve fixation element may be made from a more resilient or elastically material for ease of receiving the sleeve mount or the ring mount and for possibly allowing to accommodate deformations and/or stress of these parts. For example, the sleeve fixation element can be injected from a softer polymer material than the fitting body.

[00032] It is important to consider that the material of the fitting body must be harder than the material of the pipe surface in contact with the fitting body if a tight engagement is to be provided for radially between the pipe and the fitting body.

[00033] A full plastic press fitting can also be contemplated.

[00034] It should be noted that there is no need for pipe preparation if the fitting body does not contain an O-ring.

[00035] The present invention further proposes a method of connecting a press fitting as described above with a pipe end, comprising the steps of: inserting the pipe end into a pipe insertion space between a fitting support and a compression sleeve; rotating the compression sleeve around the fitting support to adjust the rotational position of the compression sleeve, and applying the crimping force on the crimping ear(s), to close the ear(s), leading to the crimping of the pipe end against the fitting support. The method has among others the ad vantage that for easy access for the crimping tool it is sufficient to turn the undeformed compression sleeve.

[00036] In an aspect, during application of the crimping force, a/the anti-ovalisation tongue slides or moves within a/the corresponding anti-ovalisation channel in the compres sion sleeve. [00037] The total closing of the ear(s), and hence of the sleeve body, and/or the mutual position of the anti-ovalisation tongue and the anti-ovalisation channel, can be a visual indi cation for a correct crimping process.

[00038] The invention also proposes the use of a press fitting such as described, wherein a crimping tool is configured to transmit the crimping pressure to the compression sleeve.

[00039] The invention also concerns a crimping process including the application of crimping pressure, by a crimping tool, on a compression sleeve of a press fitting.

[00040] Brief Description of the figures

[00041] Other characteristics and advantages of the invention will be more clearly evi dent upon reading the description of several currently preferred embodiments, provided as examples only, with reference to the attached drawings, wherein:

Figure 1 shows a view of a press fitting according to a first aspect of the present inven tion,

Figure 2 is an isometric view of a main body for a press fitting of Figure 1,

Figure 3 is a front cross-sectional view of the main body of Figure 2,

Figure 4 is a front view with hidden lines of the main body of Figure 2,

Figure 5 is an isometric view of another main body for a press fitting of Figure 1, Figures 6 and 7 show a compression sleeve for a press fitting of Figure 1 in one aspect of the invention,

Figures 8 to 12 shows detail of the compression sleeve of Figures 6 and 7 in one aspect of the invention,

Figure 13 shows a crimping process according to one aspect of the invention,

Figure 14 shows a view of a compression sleeve according to an alternative aspect of the present invention,

Figure 15 is another view of the compression sleeve of Figure 14,

Figure 16 shows an exploded view of the press fitting with a compression sleeve of Figure 14,

Figure 17 shows a view of a compression sleeve according to an aspect of the present invention, and Figure 18 a view of a compression sleeve of Figure 17 according to an aspect of the present invention.

[00042] In the figures, identical parts are identified using the same reference numbers.

[00043] Figure 1 shows a press fitting 1 allowing the connection of a tube according to one aspect of the present invention. The tube may be for example a pipe of a piping system for hot and cold-water installations inside buildings.

[00044] In the example of Figure 1, the press fitting allows the connection of two tube at both sides, but this is not limiting the invention. The fitting may form one side of a connector having similar or another kind of fitting on its other end or side. The fitting may also be provided at a port of a fluidic device for connecting a pipe thereto.

[00045] The mechanical fitting comprises a main body 10 for receiving a pipe end to be connected and compression and fixation assembly with a compression sleeve 20 provided to be crimped on the pipe end.

[00046] As can be on figures 2 to 4, the main body 10 comprises a fitting portion 12 with a fitting support 15 extending axially from the fitting portion 12. The fitting support 15 ex tends in the axial direction X-X between said fitting portion 12 and a pipe insertion end 13.

[00047] The compression sleeve 20 is designed to surround the fitting support 15. The fitting support 15 and the compression sleeve 20 defines an insertion space 18 for the inser tion of the pipe end to be fixed (Figure 1).

[00048] The fitting support 15 has a plurality of radial recesses 17 extending on its outer circumference, which allow to grip the pipe. The radial recesses or grips 17 on the fitting portion 12 of the fitting support ensures good grip of the compression sleeve.

[00049] The compression sleeve 20 comprises a sleeve body 21 in a form of an open ring with two annular ends 22, 23, facing each other. The annular ends 22, 23 are connected by two crimping ears 26 projecting radially outwardly from the sleeve body 21. [00050] The crimping ears 26 are deformed and the annular ends 22, 23 of the sleeve body move towards each other during the crimping process to close the sleeve body 21. The total closing of the ears, and hence of the sleeve body 21, is a visual indication for right crimping process.

[00051] The compression sleeve 20 is designed with two crimping ears 26 axially spaced apart. Providing two crimping ears in series provide a good mechanical resistance to main tain the pipe under operational condition.

[00052] The compression sleeve 20 comprises a fitting body mount 56 and the fitting portion comprises a sleeve fixation element 47. The fitting body mount 57 and the sleeve fixation element 47 cooperate so that the compression sleeve 20 is axially maintained on the fitting support and freely rotatable around said fitting support 15.

[00053] In the example of the figures, the sleeve fixation element 47 is a circumferential slider 47 in the fitting portion 12 of the main body 10 for holding the compression sleeve.

[00054] As best seen on Figures 6 and 7, in this embodiment the compression and fixation assembly is constituted by the compression sleeve 20, that has two axial fitting body mounts 56 extending axially from the sleeve body 51, each axial fitting body mount 56 being pro vided with a radial projections 57 projecting radially from its inner surface.

[00055] The radial projections 57 act as fixing stoppers to be received in the slider 47 in the fitting portion 12 of the main body 10.

[00056] This arrangement allows holding the compression sleeve 20 in the axial position whilst providing the compression sleeve a freedom of rotational movement around said main axis, when mounted to the main body 10, at least until the compression sleeve has been compressed.

[00057] In the example of the Figures, the circumferential slider 47 is formed by a cir cumferential groove in the fitting portion, between a first stopper 45 on the axially inner side of the fitting portion and a second stopper 46 located axially outwardly form the first stopper 45. A cover 48 extends axially outwardly from the outward radial end of the first stopper 45. The cover 48 extends above the circumferential slider 47 and the second stopper 46, and defines an insertion space 49 for the radial projection of the compression sleeve to be clipped inside said circumferential slider 47.

[00058] The number of projections is not limiting the invention. The compression sleeve 20 may have a single circumferential projection or one or more radial projection to be fixed between two stoppers 45 on the main body 10.

[00059] Alternatively, the compression sleeve may as well be provided with a recess co operating with a projection of the fitting portion, or any other fixation arrangement can be contemplated.

[00060] The radial projections 57 allow to fix the sleeve 20 directly on the main body without any intermediate support in a way which provide a sleeve the ability of 360° rotation around the main body. A rotational movement of sleeve is providing for a comfortable po sition of crimping tool during the crimping process.

[00061 ] In addition, panoramic windows 19, extending circumferentially between the ax ial fitting body mounts 56, are provided on the compression sleeve 20 to monitor the pipe insertion.

[00062] In the example of figures 6 and 7, the axial fitting body mounts 56 of the com pression sleeve are designed with a radial projections 57 projecting radially from its inner surface to be received in the slider 47 in the fitting portion 12 of the main body 10. Therefore, the compression sleeve of figures 6 and 7 is fixed directly to the fitting portion 12. As will be described later with reference to figures 14 to 18, it is possible to have an additional fixation ring fixing the compression sleeve to the fitting portion. It is also possible that a decoupling element is provided to the compression sleeve to be arranged between the sleeve body and the mount or mounts.

[00063] In addition, in the example of Figures 2 to 4, the main body 10 is a one-piece member. In another embodiment shown on figure 5, the main body 210 can be made as two parts, depending on injection requirements. In both embodiments, the main body maintains and holds the compression sleeve in the same manner, with a freedom of rotational move ment of sleeve around said main body. [00064] The compression sleeve 20 is provided with an anti-ovalisation tongue 60 de signed to distribute the crimping force around the pipe and the main body, thereby limiting the ovalisation of the main body during crimping process. In addition, the anti-ovalisation tongue 60 also prevents the pipe flow into the crimping ears 60 during the crimping process. This ensures full jointing between the pipe and the body and avoid leakage.

[00065] The anti-ovalisation tongue 60 is an annular projection extending from the an nular end 22 towards the annular end 23. The anti-ovalisation is designed to move into an anti-ovalisation channel 65 of the sleeve body 21 during crimping process.

[00066] In the embodiment of Figures 8 to 12, the anti ovalisation tongue 60 is provided between the two crimping ears 26.

[00067] Preferably, the anti-ovalisation tongue 60 has the same thickness as the compres sion sleeve 20. The thickness of sleeve 20 depends on the diameter of the press fitting, for example the thickness of sleeve can vary from 0.6 to 1.2 mm for mechanical fitting DN 12 to DN 32. The sleeve could be thicker for larger diameter.

[00068] The width of the anti-ovalisation tongue 60 can vary from 0.5 to 1.5 the width of the crimping ear 26. The width of the crimping ear can vary between 3 to 12 mm depend ing on the diameter of mechanical fitting.

[00069] The length of the anti-ovalization tongue can be vary from 0.5to 0.75 length of ear. The length of ears depends on the diameter of mechanical fitting.

[00070] The compression sleeve 20 is manufactured from a deformed metal sheet. The metal sheet is cut and deformed to give the two crimping ears 26 and an anti-ovalisation tongue 60. The ears are formed by bending a tab 28 around other extreme of metal sheet via the rectangular holes 29. The channel 65 is formed to receive the anti-ovalisation tongue 60.

[00071] The compression sleeve can be manufactured by cutting, punching and cold de forming process. However, welding or similar process can be included for mechanical fitting with large diameter. [00072] The pipe or tube can be mono material and made of thermoplastic materials in cluding but not limited to PE, PB, PEX, PERT, PER, PPS... or Composite (multi material tube structure) with different layers of functional materials (PEX, PERT, PVDF, Alumin ium.. The material for the fitting body can be metal (brass, Stainless steel....) or Thermo plastic (PVC, PPSU, PVDF, thermoplastic with fibre glass reinforcement).

[00073] It is important to consider that the material of the fitting body must be harder than the material of the pipe surface in contact with the fitting body.

[00074] A method for connecting a tube and a press fitting is shown on Figure 13. The method comprises the step of inserting the pipe (step SI) into the space insertion 18, and rotating the compression sleeve around the main body and the pipe inserted (step S2), and applying the crimping pressure on the crimping ears 26 until the ears are closed (step S3).

[00075] During the deformation of the crimping ears, the anti-ovalisation tongue slides in the corresponding channel.

[00076] The compression sleeve is preassembled and there is no need to reposition the compression sleeve before the crimping process. During the crimping processes, the gaps between the ears will crush and disappear. Therefore, the compression sleeve will be main tained securely in the compressed state as the radial ends have been brought together by pinching the ear or ears. The ear/ears will avoid any inadvertent loosening as they have been deformed plastically in an irreversible manner.

[00077] It should be noted that there is no need for pipe preparation even if the fitting body does not contain an O-ring.

[00078] There is no need to pipe preparation or multi-body part assembling during in stallations.

[00079] In the example of figures 6 and 7, the axial fitting body mounts 56 of the com pression sleeve are designed with a radial projections 57 projecting radially from its inner surface to be received in the slider 47 in the fitting portion 12 of the main body 10. Therefore, the compression sleeve of figures 6 and 7 is fixed directly to the fitting portion 12. Figures 14 to 18 show another embodiment of a compression and fixation assembly with a compres sion sleeve 200, in which the compression and fixation assembly comprises a fixation ring 270 for mounting the compression sleeve to the fitting portion.

[00080] The compression sleeve 200 comprises a sleeve body 221 in a form of an open ring with two annular ends 222, 223, facing each other. The annular ends 222, 223 are con nected by two crimping ears 226 projecting radially outwardly from the sleeve body 221.

[00081] The crimping ears 226 are deformed and the annular ends 222, 223 of the sleeve body move towards each other during the crimping process to close the sleeve body 221. The total closing of the ears, and hence of the sleeve body 221, is a visual indication for right crimping process.

[00082] The compression sleeve 200 is designed with two crimping ears 226 axially spaced apart. Providing two crimping ears in series provide a good mechanical resistance to maintain the pipe under operational condition.

[00083] The compression sleeve 220 comprises a fitting body mount 256 and a fixation ring 270 is provided as an intermediate fixation piece between the fitting body mount 256 of the compression sleeve and a sleeve fixation element 247 of a fitting support 215, as seen on Figure 16.

[00084] The fitting body mount 256 is fixed to the fixation ring 270 in a freely rotatable manner, and the fixation ring 270 is fixed to the fitting support 215. Thus, the fitting body mount 256, the fixation ring 270 and the sleeve fixation element 247 of the fitting support cooperate so that the compression sleeve 200 is axially maintained on the fitting support and freely rotatable with respect to said fitting support 215.

[00085] The fixation ring 270 has a circumferential slider 277 on one axial side and a fitting mount 287 on its other axial side. The circumferential slider 277 is provided for re ceiving the fitting body mount 256 of the compression sleeve in a freely rotatable manner. The fixation mount 287 is provided to fix the fixation ring to the fitting portion of the main body 210. [00086] This arrangement allows holding the compression sleeve 220 in the axial posi tion whilst providing the compression sleeve a freedom of rotational movement around said main axis, when mounted to the main body 210.

[00087] The number of projections is not limiting the invention. The compression sleeve 220 may have a single circumferential projection or one or more radial projection.

[00088] Alternatively, the compression sleeve may as well be provided with a recess co operating with a projection of the fitting portion when directly mounted to the fitting support, or with a projection of the fixation ring when mounted to the fitting support via a fixation ring, or any other fixation arrangement can be contemplated.

[00089] A rotational movement of sleeve is providing for a comfortable position of crimping tool during the crimping process.

[00090] Providing an additional fixation ring for mounting the compression sleeve to the fitting support allows absorbing the crimping forces exerted on the compression sleeve dur ing the crimping process. This allows a more robust assembly. For example, as explained with reference to figures 6 to 13, the compression sleeve can be made of metal providing for permanent deformation once crimped. The additional fixation ring can be made of another material providing for more elasticity, such as a softer polymer material than the body, to absorb the mechanical constraints exerted on the compression sleeve during the closing of the ears.

[00091] In addition, panoramic windows 219, can provided on the compression sleeve 200 or on the fixation ring 270 to monitor the pipe insertion.

[00092] In the example of Figures 2 to 4, the main body 10 is a one-piece member. In another embodiment shown on figure 5, the main body 210 can be made as two parts, de pending on injection requirements, with one or more material. For example, the material for the fitting body can be metal (brass, Stainless steel....) or Thermoplastic (PVC, PPSU, PVDF, thermoplastic with fibre glass reinforcement). It is possible to have the fitting portion 12 in the same material as the body in the first embodiment and the separate fitting portion 212 in another material different from the fitting body in the example of Figures. 6-7, pref erably a softer polymer material than the main body. [00093] In the embodiment of Figures 14 to 18, the fixation ring 270 has also the function of retaining the compression sleeve and can be made in a softer polymer material than the main body of the fitting.

[00094] The compression sleeve can be made of stainless steel, but this is a non-limiting example. The fixation ring can be made of plastic.

[00095] In all embodiments, the compression sleeve is maintained on the main body in the same manner, with a freedom of rotational movement of sleeve around said main body.

[00096] The compression sleeve may also be provided with two fitting mounts on both axial ends, as seen on Figures 17 and 18.

[00097] The press fitting 1 according to the present invention has significant impact on the crimping tool and its ergonomic. The amount of force required to crimp this technology is very low in comparison with existing mechanical fitting the amount of energy reduction is up to 70 %.

[00098] The sleeve can be rotated 360°, the ears aligned in series in one line, the tool does not need to surround the mechanical fitting to processed crimping process. These char acteristics allow to reach easily difficult crimping installation position such as narrow corner of roof or reach partially hiding position.

[00099] In addition, this technology has very important impact on reducing the number of crimping tools. The dimensions of ears are relatively close for different mechanical fitting diameter, thus, only one tool can crimp wide range of mechanical fittings, for instance from DN 12 to DN 32 mm.