JP4194810B2 - Method for confirming tightening of press-type fittings and press-type fittings - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for confirming the tightening of a press-type pipe joint for caulking the periphery of the connection pipe where it fits, and a press-type pipe joint.
[0002]
[Prior art]
The press-type pipe joint is formed by forming a pipe member such as stainless steel as a joint by plastic working or the like, and has a receiving port that expands an inner diameter of a portion into which a connection pipe is inserted. This receiving part is caulked with a press tool and tightly connected to the connecting pipe by the restriction, but this alone is insufficient for airtightness and watertightness and may cause liquid leakage. An annular groove that opens inward is provided in part, and an O-ring is fitted into the annular groove.
[0003]
For press-type fittings, caulking is the most important and most important matter for construction, but sometimes it is forgotten to tighten, and even if it is forgotten to tighten, it cannot be checked only by the presence or absence of deformation of the caulking. There was a case of causing a major accident by operating as it is. When the piping work is completed, a water pressure (or air pressure) test is performed to check for water leaks, but even if there is no caulking, it may not leak due to the function of the O-ring alone, so forget to tighten. May be overlooked, and the water pressure test was not reliable in detecting forgotten tightening.
[0004]
[Problems to be solved by the invention]
To make it possible to detect forgotten tightening in the water pressure test, it was thought that the O-ring function would not be exhibited simply by inserting a connecting pipe into the O-ring. About this, if the idea is to allow the inner diameter of the O-ring to be slightly larger than the outer shape of the connecting pipe, the positioning when the connecting pipe is inserted becomes unstable and cannot be adopted. There is a proposal to provide a concave part sandwiched by the bulging convex part in a part of the ring (Japanese Utility Model Publication No. 6-33258).
[0005]
According to this, when the connecting pipe is inserted, the recess of the O-ring is not yet completely crushed, thereby creating a gap through which water passes between both the pipe joint and the connecting pipe. In this case, water leakage will occur so that it is possible to confirm that the tightening is forgotten. However, when the annular groove has the minimum manufacturing tolerance and the connecting pipe has the maximum manufacturing tolerance, a gap may not be generated depending on the way of piping work, and there is a case where water leakage does not occur in the water pressure test. Further, since the convex portion protrudes from the insertion of the connecting pipe and the O-ring may come off from the annular concave groove, or the O-ring may be damaged, it could not be said that it is a preferable measure as a pipe joint.
[0006]
In view of the above circumstances, the present invention can reliably detect forgotten tightening, so that the safety of piping can be secured so as not to cause a liquid leakage accident, and the press type tightening confirmation method, and press type The object was to provide a pipe joint.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a press-type pipe joint in which an annular groove is provided on the inner periphery of a receiving port widened so that a connection pipe can be fitted, and an O-ring is fitted in the annular groove. In the pipe construction work, when the connecting pipe is inserted into the receiving port and the receiving port is caulked with a press tool, the surface color of the press fitting is determined by the caulking pressure or timing on the surface of the caulking part. Provides a different confirmation color, or conversely, an identification color that approximates the surface color of the joint.
[0008]
Because the method for confirming the tightening of press-type fittings is configured as described above, whether or not you forget to tighten can be determined by checking whether or not an identification color is attached to the receptacle of the press-type fitting in the inspection after piping construction. If the identification color is attached, the caulking is completed, and if it is not attached, the caulking work has not been completed. Therefore, by performing caulking work based on this, incompleteness is coupled with the water pressure (pneumatic pressure) test. Can prevent accidents such as water leaks and liquid leaks due to simple piping. In addition, the piping operator will not forget to tighten by visually recognizing the identification color. On the other hand, by caulking the identification color given before caulking in advance, by configuring it to be an identification color (silver color, gray, color close to stainless steel, etc.) that approximates the surface color of the joint, Tightening confirmation can be made strictly.
[0009]
Further, the present invention provides a press fitting that is provided with an annular groove on the inner periphery of a receiving port that is expanded so that a connection pipe can be fitted, and an O-ring is fitted into the annular groove. A press-type pipe joint characterized in that a pressure-sensitive paint consisting of microcapsules enclosing an identification color pigment is applied, or a pressure-sensitive color-developing tape coated with a pressure-sensitive paint is applied. It is.
[0010]
Since the press-type fitting is configured as described above, it is suitable for carrying out the above-mentioned method for confirming the tightening of the press-type fitting, and the microcapsule is destroyed by the pressure when the receiving port is caulked during piping work. The identification color appears at the pressurization site by the outflow of the contained pigment (or dye).
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The method of the present invention is to attach an identification color to the surface of the caulking portion by caulking pressure or timing when caulking the receiving port 1 with the press tool T in the piping construction work of the press type pipe joint. However, for example, there are the following modes.
[0012]
(1) The pressure-sensitive color-developing tape 7 coated with the pressure-sensitive color-developing paint 9 is coated on the caulking portion of the receiving port 1 or the pressure-sensitive color-developing paint 9 is applied (Claim 2) and tightened with a press tool. The identification color is developed by the pressure of time.
[0013]
The pressure-sensitive coloring paint 9 is a microcapsule in which a pigment (or dye) is encapsulated, and an adhesive or adhesive is attached to the microcapsule shell to form a microcapsule group, which can be applied by brush or spray. . In the case of the pressure-sensitive coloring tape 7, a sheet or film of plastic or the like having a relatively long stretch of about 20 to 200 μm is used for the tape base material, and the pressure-sensitive coloring paint 9 is applied thereto. In order to fix to the outer surface of the receiving port 1, the adhesive 10 is apply | coated to an adhesive surface. Alternatively, a double-sided adhesive tape 8 is laminated to form a composite tape.
[0014]
In addition, the microcapsule has a particle size of approximately 1 to 50 μm, and the material of the outer skin sealed with the pigment or dye is an organic material such as melamine, urethane, acrylic, nylon, or gelatin. And inorganic materials such as silicon dioxide and alumina are used. Depending on the material, the outer skin may be coated with an appropriate color so that the color of the core substance cannot be seen through. In addition, when a dye is selected as the core substance, it is desirable to take measures for preventing deterioration and fading due to ultraviolet rays.
[0015]
(2) A heat-sensitive tape or film is applied to the caulking portion of the receptacle, or a heat-sensitive material is applied, and an identification color is developed by heat such as frictional heat generated when tightened with a press tool. Further, a heater may be incorporated in the die portion of the press tool so as to apply color development heat.
[0016]
(3) An identification color paint is applied to the caulking portion of the receptacle, and a film that peels off or disappears by the pressure when caulking the press tool is coated thereon, and the identification color is exposed by caulking.
[0017]
(4) A colored tape or film is coated on the caulking portion of the receiving port, and peels off or disappears by the pressure when caulking with the press tool to expose the background of the joint.
[0018]
(5) The press tool can be devised. For example, the press tool T is provided with a nozzle, an application brush, and a spray from which the paint of the identification color is leached, and the paint is applied to the press-type pipe joint at the caulking timing.
[0019]
In addition to the above, the form is not particularly limited as long as an identification color is expressed or attached at or near the caulking portion when caulking with the press tool T. The press-type pipe joint is a metal pipe made of stainless steel, iron, copper or the like formed into a socket, elbow, tee, reducer, etc. by plastic working or the like, and has an annular groove 3 in which the O-ring 5 is fitted. Regarding the position, there are a case where it is the opening edge of the receiving port 1 (FIG. 1) and a case where it is halfway between both ends of the receiving port (FIG. 6).
[0020]
【The invention's effect】
As described above, according to the present invention, in the inspection after the pipe construction by the press-type fitting, it is possible to surely find forgetting to tighten by the presence or absence of the identification color, and to reduce the forgetting to tighten, the liquid leakage accident This has an excellent effect that the safety of piping can be ensured, and the workability of inspection is also improved.
[0021]
【Example】
Next, an embodiment of a press-type pipe joint according to the present invention will be described with reference to the drawings.
[0022]
FIG. 1 to FIG. 4 show an embodiment, and its press fitting F is a socket, and is expanded so that connection pipes P and P can be inserted into both ends of a straight stainless steel pipe. The receiving ports 1 and 1 are formed, and the annular grooves 3 and 3 are formed on the opening edge of the receiving ports 1 and 1 by curl pressing or the like, and the O-rings 5 and 5 are fitted into the annular grooves 3 and 3. Further, pressure-sensitive color developing tapes 7 and 7 are attached to the outer circumferences of the receptacles 1 and 1 at locations where the press tools T are caulked. Since the O-ring 5 is formed to have an inner diameter slightly smaller than the outer diameter of the connection pipe P, the O-ring 5 is brought into close contact with the outer periphery at the same time as the connection pipe P is inserted into the receiving port 1.
[0023]
The press tool T is caulked to a hexagonal shape or an octagonal shape by the upper and lower molds 2, 2, and has caulking protrusions 4, 4 on the inner periphery. Alternatively, the identification colors 11, 11,.
[0024]
The pressure-sensitive coloring tape 7 is made of a 100 μm-thick polyester or polyolefin film having elasticity and elasticity, and is cut into a ring (FIG. 4). A pressure sensitive adhesive 10 is applied. As for the attachment, the ring is widened against the elastic force so as to get over the outer peripheral projection of the annular groove 3, and is attached by restoration at a predetermined location and thermal contraction by heating.
[0025]
The pressure-sensitive color-developing paint 9 is obtained by encapsulating a red pigment in a capsule, and when it is caulked by a press tool T, it develops a red identification color 11 (FIG. 3). Further, the pressure sensitive adhesive 10 is a capsule in which an adhesive is sealed, and the adhesiveness is generated only by pressurization. Easy to wear. Further, since the pressure-sensitive adhesive is exposed from the microcapsule by caulking, the tape sticks to the receiving port 1 at that time, and even if the tape is broken, the pigment remains and remains in a predetermined position.
[0026]
FIG. 5 shows another embodiment of the pressure-sensitive color developing tape 7. The double-sided adhesive tape 8 is adhered to the back surface of the tape body 7 a so that it can be adhered to the outer surface of the receiving port 1.
[0027]
FIG. 6 shows another embodiment of the press-type fitting F as an elbow. The receiving ports 1 and 1 are provided with annular grooves 3 and 3 between both ends thereof. The pressure-sensitive color-developing paints 9 and 9 are applied across both sides of 3.
[0028]
In the above embodiment, the case where the surface of the caulking portion is given an identification color different from the surface color of the joint by caulking pressure has been described. However, contrary to this embodiment, before the caulking pressure is applied. In addition, the object of the present invention can be achieved even if the surface of the caulking part is previously provided with an identification color and the surface of the caulking part has an identification color that approximates the surface color of the joint by caulking pressure. Is something that can be done.
[Brief description of the drawings]
FIG. 1 is a partially cut-away sectional view showing a press-type pipe joint according to the present invention in a usage manner.
FIG. 2 is a cross-sectional view showing a position immediately before caulking in AA in FIG. 1;
FIG. 3 is a partially cutaway sectional view showing a pipe construction completion state in which the press-type pipe joint is caulked.
FIG. 4 is a perspective view of a pressure-sensitive color developing tape in the same example.
FIG. 5 is a perspective view of a pressure-sensitive color developing tape according to another embodiment.
FIG. 6 is a cross-sectional view corresponding to FIG. 1 showing another embodiment.
[Explanation of symbols]
F Press type pipe joint P Connection pipe T Press tool 1 Receptor 3 Annular groove 5 O-ring 7 Pressure sensitive coloring tape 9 Pressure sensitive coloring paint

Claims (2)

An annular groove is provided on the inner periphery of the receiving port that is expanded so that the connection pipe can be fitted, and in the piping work of a press-type fitting in which an O-ring is fitted into the annular groove, the connection pipe is connected to the receiving port. After the insertion, when the receptacle is caulked with a press tool, the surface of the caulking part is given an identification color different from the surface color of the press fitting due to caulking pressure or timing, or vice versa. A method for confirming the tightening of a press-type pipe joint, characterized in that a color approximate to the surface color of the joint is attached by caulking the identification color before caulking. In press-type fittings in which an annular groove is provided on the inner periphery of the receptacle that is expanded so that the connection pipe can be fitted, and an O-ring is fitted in the annular groove, a pigment having an identification color at the caulking portion of the receptacle A press-type pipe joint, characterized in that a pressure-sensitive paint composed of microcapsules in which is encapsulated is applied, or a pressure-sensitive coloring tape coated with a pressure-sensitive paint is applied.

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