JPS62113987A - Corrosion-protective pipe joint - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] There is a pipe joint shown in FIG. 4 disclosed in No. 86.

This type of pipe fitting has a cylindrical body 5 that connects an inner resin-lined pipe 4 and is in contact with the inner surface of the pipe 4, and protects the pipe and the metal part of the joint from the internal fluid and prevents corrosion of the pipe. It also has the effect of preventing red water from forming inside the pipes.

The above-mentioned conventional anti-corrosion pipe joint exhibits a corrosion-preventing effect on the pipe end surface and the inner surface of the joint when connected to a pipe with an internal resin lining. However, when connecting to a hydrant at the end of the piping, there is almost no problem since the hydrant is made of a corrosion-resistant copper alloy, but the connection cannot be made because the wall thickness at the connection end is thicker than that of the pipe. .

For this reason, even if it is connected to a resin-coated joint with the inner surface of the joint from which the cylindrical body 5 is removed, the alignment with the piping is limited to the female thread of the pipe joint, since the hydrant is mainly installed inside a building. Generally, it is adjusted by the length of the threaded connection. For this reason, if the threaded length is shortened in order to increase the piping length, the threaded end portion of the female thread of the pipe joint will come into contact with the internal fluid, causing corrosion and generation of red water.

Ru.

[Means for Solving the Problem] This is a corrosion-resistant pipe joint characterized in that it is formed and the inner surface of the central portion excluding the female threaded portion is coated with a synthetic resin layer approximately equal to the inner diameter of the female thread.

[Function] Even if the threaded length is shorter than the specified length when the faucet equipment, etc. is screwed together, the female thread length on the joint side is also shortened, so an unthreaded thread remains on the female thread side. In addition, if the thread length is longer than the above, the metal male thread of the faucet will not fit into the synthetic resin layer in the center of the pipe fitting, even if the female thread length is short. Since the threads are carved and screwed together, the connection is made without any problems, and since the female threaded part of the pipe joint is covered by the male threaded metal part of the faucet, it does not rust and prevents the formation of red rust. can.

Furthermore, by applying Teflon coating to the female thread, even if the threaded length with the male thread is short and the female thread on the joint side may be exposed, it is coated with Teflon and rust can be prevented. Corrosion protection is completely achieved.

[Example] Cheese may be used. The length of the female thread 2 at one end A side of the joint body 1 is approximately half the length specified by JIS, and the inner surface of the female thread is coated with Teflon paint 7. The length of the female thread 6 on the other end 8 side is formed as specified. The central portion 8 of the joint body 1 is covered with a synthetic resin layer 3 at the hollow portions of the female threads at both ends. The inner diameter of the synthetic resin coating layer 3 on the female thread 2 side is formed to be approximately the same as the inner diameter of the female thread 2, and the other end on the female thread 6 side matches the inner diameter of the internal resin-lined steel pipe 4 to be threadedly connected. A cylindrical portion 5 is formed to protrude from the inner surface of the central synthetic resin layer 3 toward the end B side.

[Effect] Therefore, when the faucet device 8 is screwed onto the end A side as shown in FIG. Since the joint body 1 is screwed together, there is no exposed part of the joint body 1 on the inner surface of the joint body, and it is not corroded by the internal fluid.

Furthermore, as shown in FIG. 3, even if the length of the threaded connection with the faucet device is extremely short, the exposed female threaded portion is protected from corrosion because the inner surface of the female thread 2 is coated with Teflon paint 7.

In Naoki Minoru, we have shown an example in which only one end of the internal female thread of the joint is formed shorter than the specified female thread length, but if necessary, the female threads at both ends may be formed shorter than the specified female thread length to combine. It may be coated with a resin layer.

[Brief explanation of drawings]

FIG. 3 is a partial sectional view showing a case where the threaded length with the external thread of the faucet device is extremely short, and FIG. 4 shows a conventional example. 1...Joint body, 2, 6...Female thread. 3...Synthetic resin coating layer, 5...Cylindrical part. 7...Teflon paint. / Pan-゛... Agent Patent Attorney Tachibana Takaishi ('I, T, -!
, :”. ,) Fig. 7 Fig. 5; Shade

Claims (1)

[Claims] 1. The length of the female thread of a metal joint having female threads on the inner surfaces of both ends is shorter than the specified thread length, and the inner surface of the central portion excluding the female threads is covered with a synthetic resin layer approximately equal to the inner diameter of the female thread. A corrosion-resistant pipe fitting characterized by being coated with. 2. The anti-corrosion pipe joint according to claim 1, wherein a Teflon coating is applied to the surface of the female thread on the inner surface of the end portion.