JPS6313076B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for sealing an end surface of a tube, and more particularly to a method suitable for easily sealing an open end surface of a tube.

Figure 1 is an explanatory diagram of piping, and in Figure 1,
Piping 3 connected between container 1 and container 2 connects piping elements 3-1, 3-2, 3-3 to 4-1 to 4-4.
The parts are joined by welding. In this case, for example, welding line 5 is attached to piping element 3-1.
-1 and 5-2, it is often prescribed by law to conduct a water pressure test on the piping element 3-1 before assembling it as described above.

Therefore, conventionally, as shown in FIG. 2, blind lids 6 and 7 are attached to both opening end faces of the piping element 3-1 by welding 8 and 9, respectively, and a nozzle 10 attached to the blind lid 7 is used to form vertical piping. Water pressure was applied to element 3-1 to perform a water pressure test on piping element 3-1. FIG. 3 is a sectional view of the nozzle 10 of FIG. 2, and 10a is a pressure gauge. In this case, welding of the blind lids 6 and 7, cutting after the water pressure test, and finishing work are required. In addition, if the piping element 3-1 is a thin-walled pipe, the cross-sectional shape of the end surface becomes irregular due to welding and cutting, and the connection state of the butt weld with other piping elements, for example, piping element 3-2, becomes poor. , the strength and reliability of the welded part may deteriorate, causing problems.

The present invention has been made in view of the above, and its purpose is to provide a seal for the end surface of a tube that can be easily and quickly sealed on the open end surface of the tube when performing a water pressure test of the tube. The purpose is to provide a method.

A feature of the present invention is that a ring-shaped elastic body is arranged around the outer circumference of a circular load rod, one of the elastic bodies is received by a rod head fixed to the tip of the load rod, and the other is slid onto the base of the load rod. After inserting the sealing device into the end surface of the pipe, which is supported by the movably inserted restraint frame, the restraint frame is fixed to the end face of the pipe, and then an axial load is applied to the load rod, and the reaction force is A compressive load is applied to the elastic body by receiving it in the restraining frame, and at that time, the elastic body expands in the radial direction and comes into close contact with the inner surface of the tube, which seals the open end surface of the tube. The point is that I tried to do it.

An embodiment of the method of the present invention will be described in detail below with reference to FIGS. 4 to 6.

FIG. 4 is a sectional view showing an example of a tube end face sealing device for explaining an embodiment of the method of the present invention. In FIG. 4, 11 is a load rod with a circular cross section, and 12 is a screw 1 at the tip of the load rod 11.
Load rod head fixed by screwing into 3, 14
1 is an elastic body such as a ring-shaped rubber disposed around the outer periphery of the load rod 11; 15 is a load nut;
Reference numeral 6 denotes a restraint frame slidably inserted into the load rod 11, and by tightening a nut 15, a compressive load can be applied to the elastic body 14 by the load rod head 12 and the restraint frame 16. 17 is a restraint bolt, 18 is a restraint cylinder, 19 is a load rod 1
This is the pressure applying hole provided in 1.

FIG. 5 is a diagram showing an example of the constrained cylinder shown in FIG.
A is a side view, and b is a plan view. The restraining cylinder 18 is provided with an arbitrary number of notches 20 so that the restraining bolt 17 can be tightened to the outer periphery of the tube 3 through the notches 20 when the restraining frame 16 is fixed to the outer periphery of the tube 3. It is set as.

Next, one embodiment of the method of the present invention will be described using FIG. 4. When sealing the open end surface of the tube 3 for a water pressure test or the like, first, the restraining cylinder 18 is inserted around the outer periphery of the tube 3. Next, the load rod 1 mentioned above is
1, rod head 12, elastic body 14, nut 15
Then, a sealing device consisting of a restraint frame 16 or the like is inserted into the tube 3 until the restraint frame 16 contacts the end surface of the tube 3 to be sealed. After that, the restraint frame 16 is tightened by the restraint bolt 17.
is fixed to the outer periphery of the tube 3 via a restraining cylinder 18.
Next, tighten nut 15. In this way, since the load rod 11 moves in the direction of arrow A in the figure, the elastic body 14 moves between the rod head 12 and the restraining frame 1.
6 is compressed in the axial direction, and the elastic body 14 expands in the radial direction. Therefore, the elastic body 14 is in close contact with the outer periphery of the load rod 11 and the inner periphery of the tube 3, and
1 and tube 3 are sealed.

Next, referring to FIG. 6, the watertightness provided by the elastic body 14 will be explained. Now, assuming that the watertight pressure is P ₀ , the contact pressure between the elastic body 14 and the inner circumference of the tube 3 and the outer circumference of the load rod 11 is P, and the coefficient related to the material of the elastic body 14 is m, the following equation holds true. .

P ₀ =P1/m (1) Note that m in equation (1) is close to 1 when the elastic body 14 is made of rubber. On the other hand, the appropriate length L of the elastic body 14 of the sealing device is expressed by the following equation from the balance between the axial load generated by water pressure and the frictional reaction force of the elastic body 14.

L=1/4・1/μ・D _i ² −d ₀ ² /D _i ...(2) Here, D _i : Inner diameter of pipe 3 d ₀ : Outer diameter of load rod 11 μ : Friction coefficient For example, In Figure 6, D _i =100mm, _d0 =60
If mm, in the case of rubber, μ = 0.5, so
From formula (2), L=32mm.

Therefore, if the opening end surface of the tube 3 is sealed using the sealing device shown in FIG. 4, the tube 3 can be easily sealed without any processing or welding of other parts. . And removal is also extremely easy. Moreover, when performing a water pressure test by applying water pressure from the pressure applying hole 19, if the length of the elastic body 14 is selected using equation (2), the seal will be perfect, and furthermore, the water pressure P ₀ If becomes large,
Since the contact pressure between the elastic body 14 and the inner periphery of the tube 3 and the outer periphery of the load rod 11 is proportionally increased, no sealing problems arise.

In addition, since the restraining cylinder 18 is arranged around the outer circumference of the tube 3, the deformation of the tube 3 in the radial direction is restrained.
The deformation follows the inner diameter of the restraining cylinder 18, and no problem will arise in subsequent butt welding of the pipes. On the other hand, if the end face of the tube 3 is not perfectly round before sealing, it can be corrected into a perfect circle.

As explained above, according to the present invention, there is an effect that the open end surface of the tube can be easily and quickly sealed when performing a water pressure test of the tube.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of piping, Figure 2 is a diagram to explain the conventional water pressure test method for piping elements, and Figure 3 is an explanatory diagram of piping.
The figure is a cross-sectional view of the nozzle in Figure 2, Figure 4 is a cross-sectional view showing an example of the sealing device, Figure 5 is a structural diagram of the restraining cylinder in Figure 4, and Figure 6 is an explanatory diagram of load balance. be. 3... Pipe, 11... Load rod, 12... Rod head, 14... Elastic body, 15... Load nut, 16...
Restriction frame, 18. Restriction cylinder, 19. Pressure application hole.

Claims (1)

[Claims] 1 A ring-shaped elastic body is arranged around the outer periphery of a circular load rod with a through hole in the center, one of the elastic bodies is received by a rod head fixed to the tip of the load rod, and the other is received by the rod head fixed to the tip of the load rod. A sealing device that is received by a restraining frame slidably inserted into the base of the pipe is inserted into the end face of the pipe, and the restraining frame is tightened to the outer periphery of the pipe via a restraining cylinder arranged around the outer periphery of the pipe. The load rod is fixed to the end face of the elastic body, and an axial load is applied to the load rod, and the reaction force is received by the restraint frame to apply a compressive load to the elastic body, and the elastic body expands in the radial direction. A method for sealing an end face of a tube, characterized in that the open end face of the tube is sealed by making use of the fact that the end face is in close contact with the inner periphery of the tube.