JPH07280694A - Test plug - Google Patents

Abstract

PURPOSE:To provide a test plug capable of clogging a joint end without a hitch in the cylindrical section of a built-in core and a seal packing mounted on a joint body. CONSTITUTION:The external surface of the end section of a plug body 11 has a male screw section 12 screwed to the screw of a joint, a packing groove 13 continuing to the male screw section 12, and a projecting cylindrical section 14 projected from the main body 11 to the end section side in the axial direction so as to cover the outer circumference of the packing groove 13, and the length and wall thickness of the male screw section 12 are set so that a packing 15 mounted in the packing groove 13 is compressed in the state, in which a rubber ring 24 for sealing set to a resin core 22 is not moved, without hindrance to the resin core 22 on the internal surface of the joint by the end section of the male screw section 12 when the male screw section 12 is screwed to the joint.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a test plug for closing a joint end portion having a resin core built in an inner surface connected to the pipe end portion when a leak test in the pipe is conducted.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional test plug.
As shown in the figure, the conventional test plug seals by screwing the screw parts together as in the case of the normal pipe connection, and therefore the external thread of the test plug is long.

[0003]

When the above-mentioned conventional test plug is used to close a pipe end anticorrosion joint containing a resin core having, for example, a tubular portion for covering the inner surface of the pipe on the inner surface of the joint body, a test is performed. Since the length of the male thread of the plug is long, the end of the male thread hits the tubular portion of the resin core and breaks the tubular portion. Also, even if the external thread of the test plug is thinned to the wall thickness of the pipe to which it is normally connected, if the rubber ring for sealing is built in the outer surface of the tubular part, the rubber ring for sealing may not be deformed. There was a problem with the connection with the pipe after the test was completed, because it was moved to the back of the tubular part. The present invention solves the above problems and provides a test plug capable of closing a tubular portion of a built-in core and a seal packing provided in a joint body without hindering.

[0004]

SUMMARY OF THE INVENTION The gist of the present invention is a plug for closing a joint end portion having a resin core built in an inner surface connected to the pipe end portion when performing a leak test in the pipe,
On the outer surface of the end of the plug body, there are a male threaded portion to be screwed into the thread of the joint, a packing groove continuing to the male threaded portion, and a protruding cylindrical portion protruding from the body toward the end side in the axial direction so as to cover the outer periphery of the packing groove. When the screw is screwed into the joint, the end of the male thread does not interfere with the resin core on the inner surface of the joint, and the sealing rubber ring set in the resin core does not move. The test plug is characterized in that the length and the wall thickness of the male screw portion are set so as to be compressed.

[0005]

According to the present invention, the length and thickness of the male screw portion are provided as described above, and even if the male screw is screwed into the joint with a built-in core, the packing does not hinder the built-in core and the rubber ring for sealing, and the packing has a joint end portion. It is compressed and sealed with. Further, a protruding cylindrical portion is provided on the outer peripheral side of the packing to prevent the packing from extending to the outer peripheral side and coming out of the packing groove.
For this reason, the packing comes into contact with the end portion of the joint, and is reliably subjected to the compression action to perform sealing. Therefore, compared to the conventional test plug, less screwing force is required for reliable sealing,
The built-in core and rubber ring are not hindered, and the closing work can be performed easily.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial cross-sectional view showing a state in which a test plug 10 according to an embodiment of the present invention is screwed into a joint 20 with a built-in core. The joint 20 with a built-in core has a resin core 22 built in the inner surface of the joint body 21, and the core 22 is a tubular portion 23 that abuts the inner surface of the connection lining steel pipe toward the end of the joint.
Is provided. A sealing rubber ring 24 is attached to the outer surface of the tubular portion.

The test plug 10 has a cylindrical portion 14 projecting from the main body toward the end so as to cover the screw portion 12, the packing groove 13, and the outer periphery of the packing groove 13 at the end portion of the main body 11, O-ring packing 1 in this packing groove 13
5 is attached. The length and the wall thickness of the male thread portion 12 are such that the male thread portion 12 does not come into contact with the tubular portion 23 of the built-in core or the seal ring 24 when screwed into the joint 20 with a built-in core as shown in the figure, and It is thickly formed,
The central part is a closed wall. In addition, the male thread has a smaller diameter than the female thread of the joint with built-in core so that it can be fully screwed in by hand.

When the test plug 10 is screwed into the joint 20 with a built-in core as shown in FIG. 1, the O-ring packing 15 comes into contact with the end face of the joint with the male thread 12 not coming into contact with the cylindrical portion 23 of the built-in core. The screwing of the test plug 10 is stopped, the O-ring packing 15 is compressed and sealed, and the joint end is closed. Even when the test plug 10 is strongly screwed in, the O-ring packing 15 does not escape to the outer peripheral side of the O-ring groove due to the protruding cylindrical portion 14, so that the compression is reliably performed and the joint end is closed and sealed. Further, in the figure, the protruding tube portion 14 is not in contact with the end surface of the joint 20 with a built-in core, but the length of the protruding tube portion 14 is increased so as to contact the end surface of the joint with an appropriate compression amount of the packing, and the screwing amount of the plug is increased. It is possible to check the sealability of the packing.

[0009]

As described above, the test plug of the present invention can be reliably and easily closed regardless of the tubular portion of the joint with built-in core, the seal packing, and the like.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of the present invention and showing a state of being screwed into a joint with a built-in core.

FIG. 2 is a partial cross-sectional view showing a conventional technique.

[Explanation of symbols]

 10 Test Plug 11 Main Body 12 Male Threaded Part 13 Packing Groove 14 Protruding Cylindrical Part 15 O-Ring Packing 20 Joint with Built-in Core 21 Joint Body 22 Resin Core 23 Cylindrical Part

Claims (1)

[Claims] 1. A plug for closing an end portion of a joint containing a resin core on an inner surface connected to an end portion of the pipe when performing a leak test in the pipe, wherein a screw of the joint is provided on an outer surface of the end portion of the plug body. Has a male threaded portion to be screwed into, a packing groove continuing from the male threaded portion, and a protruding tubular portion protruding from the main body toward the end in the axial direction so as to cover the outer periphery of the packing groove, and when screwed into the joint, The length of the male threaded portion is such that the packing installed in the packing groove is compressed in a state where the end of the threaded portion does not interfere with the resin core on the inner surface of the joint and the rubber ring for sealing set on the resin core is not moved. A test plug characterized by setting the thickness and wall thickness.