JPS589029Y2 - lead pipe joint - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a lead pipe joint.

Lead pipes are indispensable conduits for waterworks, and soldering has long been used to connect them to faucet or branch joints.

However, since soldering does not have suitable and sufficient conditions for joining lead pipes, a better method has been desired.

In this soldering method, the joint is a narrow band-shaped connection around the joint (see Figure 1), and under high pressure, the solder joint may break off from the soldered point, and the solder is usually soldered with a torch. Since the material is melted during work, there is a risk of fire or explosion indoors or near hazardous materials.

In addition, workers need to be extremely skilled in order to achieve sufficient bonding, and bonding in a narrow space, whether indoors or outdoors, requires time and effort.

Furthermore, as seen in Registered Utility Model No. 29830, there is a known technique in which the joint and nut have the same taper, but in such joints, when the nut is tightened strongly, the tip (deepest part) of the joint The wall thickness of the lead pipe becomes thinner, and if you tighten it loosely to avoid thinning the wall thickness, gaps tend to occur on the opening side.

Furthermore, such a joint method that does not use a sealant, adhesive, or plastic ring is susceptible to corrosion at the interface between the joint and the lead pipe, and cannot withstand long-term use.

The purpose of this invention is to provide a joint that can be easily and reliably connected to a lead pipe without relying on solder, as a result of researching various joint parts in order to improve the shortcomings of the soldering method and known joint methods.

In this invention, when joining a lead pipe and a metal joint, the cut part of the lead pipe has a taper, the inner taper and the outer taper are enlarged to be different, and a metal joint having the same taper as the inside of the lead pipe is inserted. Then, connect the lead pipe and metal joint with a metal nut that has the same taper as the outside taper of the lead pipe, and apply a sealant or adhesive to the metal joint, or insert a plastic ring inside the nut to connect the lead pipe joint. be.

In this way, by having different tapers on the inside and outside of the lead pipe, it is possible to reduce deformation of the wall thickness of the lead pipe when the joint nut is tightened, and it is also possible to apply sealant or adhesive to the metal joint. Alternatively, corrosion at the interface between the joint and the lead pipe can be prevented by inserting a plastic ring inside the nut.

That is, the corrosion of metals is generally accelerated by moisture, but especially when different metals come into contact, an oxidation-reduction system is formed in the presence of moisture, causing corrosion called contact corrosion.

As stated in Registered Utility Model No. 29830,
If dissimilar metals are used as joint materials directly on lead pipes, contact corrosion as described above will occur in humid environments such as those buried underground, which can be serious if used in gas or water pipes. This may cause serious danger.

According to the present invention, when an adhesive or sealant is applied to a metal joint, the metal surfaces on the lead pipe side and the joint side and the adhesive layer or sealant layer are chemically bonded to prevent water from entering, thereby preventing contact corrosion. hard to receive.

Furthermore, when a plastic ring is inserted inside the nut, even if water enters the interface between the metal surface and the plastic ring, there is no contact between dissimilar metals, which has the advantage of being less susceptible to contact corrosion as described above.

To simplify the explanation of the drawings below, Fig. 1 is a cross-sectional view of a joint made by the conventional soldering method, and Figs. 2 to 5 show an embodiment of the present invention and its partial diagram. .

Figure 2 is an enlarged tapered cross-sectional view of the cut portion of the lead pipe, Figure 3 is a cross-sectional view of the joint, Figure 4 is a cross-sectional view of the nut,
FIG. 5 shows a sectional view of the lead pipe joint of the present invention.

Next, to explain the gist of the present invention according to the drawings, if you widen the cut end of a lead pipe in a tapered shape as shown in Fig. .

) In this case, the taper near the side opening of the lead pipe will differ between the inside and outside due to the difference in elongation of the lead pipe.

Next, a metal joint made of brass or the like as shown in FIG. 3 having the same taper as the inner taper is inserted.

In this case, even more effects can be obtained by applying a sealant or adhesive to the interface between the joint and the lead pipe.

Next, before opening the lead pipe cut part, insert the fourth
Move the nut, which has the same taper as the outside of the lead pipe as shown in the figure, to the cut part of the lead pipe and tighten the joint part (Fig. 5).

In this case, by inserting the plastic ring 5 inside the nut 4, it is possible to cope with the deviation in the thickness of the lead pipe that occurs when the cut portion of the lead pipe is widened.

This lead pipe joint connected using the above method can be connected without narrowing the diameter of the water flow part of the inner diameter of the lead pipe, and the time required for work can be reduced to one-third of the conventional method. It can be connected, and the workability is good not only in a wide place but also in a narrow place.

The effects of the present invention will be explained below with reference to Examples.

Example wall thickness: 3mm, outer diameter: 2011t? +! The lead pipe was connected to the brass joint of the present invention as shown in Figure 5.

A comparison was made between the product of the present invention and the conventional product shown in FIG. 1 in terms of connection time and withstand voltage limits.

The results are tabulated.

In addition, as a result of conducting soil burial tests and outdoor exposure tests on lead pipes connected to joints according to the present invention,
It was found that it can withstand long-term use.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a joint by conventional soldering, Figure 2
5 to 5 show an embodiment of the present invention and its partial views, in which FIG. 2 is a tapered sectional view of the cut portion of a lead pipe, and FIG.
The figure is a sectional view of the joint, FIG. 4 is a sectional view of the nut, and FIG. 5 is a sectional view of the lead pipe joint of the present invention. Code: 1...Lead pipe, 2...Soldering part, 3...Joint, 4...Nut, 5...Plastic ring.

Claims (1)

[Scope of utility model registration request] When joining a lead pipe and a metal joint, the cut part of the lead pipe has a taper, and the inner taper and outer taper are enlarged so that they are different, and a metal joint with the same taper as the inside of the lead pipe is inserted, and then the lead pipe is joined with a metal joint. A lead pipe joint in which a lead pipe and a metal joint are connected with a metal nut with the same taper as the outer taper of the pipe, and a sealant or adhesive is applied to the metal joint, or a plastic ring is inserted inside the nut.