JPH0110549Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a structure in which a pipe having a neck flange formed at the end and lined from the inner surface to the end face is connected by a housing-shaped pipe joint.

[Prior Art] In the case of piping that transports hard slurry such as earth and sand at high speed, steel pipes are used whose inner surfaces are lined with rubber or the like to prevent wear on the inner surfaces of the pipes, and housings are used to connect the pipes. type pipe fittings are used. In this connection method, in order to prevent damage to the lining applied to the inner surface of the tube, lining is also applied to the end surfaces of the tubes, the end surfaces of the two pipes to be connected are brought into close contact, and the lining is applied to the inner surface of the tube. It is desirable to protect the end faces of the lining from internal fluids.

[Problems to be solved by the invention] However, the housing-type pipe joint has a
A cylindrical gasket with an inward lip formed on the inner circumferential surface of both ends is housed, and the gasket is fitted across the outer circumferential surfaces of the neck flanges of both tubes.
Since there is a gap in the center of the inner circumferential surface of the packing, when the pressure of the fluid inside the pipe to be conveyed is high, the lining of the neck flange end face of the abutted tubes is pushed open and the fluid flows into the gap in the inner circumferential surface of the packing. may flow into the Then, when the pressure inside the pipe decreases due to stopping of fluid transport, etc., and the inside of the pipe suddenly becomes negative pressure, the fluid pressure sealed in the gap of the packing acts to push the lining of the end face toward the inner surface of the pipe. In this way, the lining on the end face portion of the neck flange may peel off.

In addition, in order to prevent the above-mentioned disadvantages, if the pipes are connected with a gap between their butting surfaces, there is a problem that vibrations may occur in the piping due to fluid pressure fluctuations when high-speed or high-pressure fluid flows. be.

The present invention provides a pipe connection structure that does not have the above drawbacks.

[Means for Solving the Problems] The gist of the present invention is to form neck flanges 2, 2 with tapered shoulders 21 at the ends of the pipes 1, 1 to be connected, and to Linings 3, 3 are applied from the end face to the end face 3 of the linings 3, 3.
At least one radial groove 32 communicating from the inside of the tubes 1, 1 to the outside is formed in at least one of the tubes 1, 31, and the groove straddles the outer peripheral surface of the neck flanges 2, 2 of the tubes 1, 1 whose ends abut each other. A cylindrical packing 4 with an inward lip formed on the inner peripheral surface of both ends.
It has an annular groove 51 for accommodating the packing 4, and both side walls 52, 52 of the annular groove 51.
By tightening the housings 5, 5, which have tapered surfaces complementary to the shoulders 21, 21 of the neck flange 2, to the outer periphery of the packing 4, the pipes 1, 1
This is a pipe connection structure characterized in that the end surfaces 31, 31 of the linings 3, 3 are brought into close contact with each other, and the pipes 1, 1 are connected, with the inside of the packing 4 communicating with the inner space of the packing 4.

[Operation] Since the present invention has the above configuration, the pressure inside the pipe and the pressure inside the packing on the outside surface of the pipe are equal because they communicate through the groove formed on the end face of the lining of the pipe, and when the pressure inside the pipe increases, Even if the pressure inside the packing becomes high and the pressure inside the pipe suddenly becomes negative, the pressure inside the packing will also become negative, and the end lining applied to the pipe will not be pushed out towards the inside of the pipe. . In addition, both inner walls of the housing are tapered and engage complementarily with the tapered shoulders of the neck flange of the tube, so by tightening the housing in the axial direction of the tube, both tubes protrude in the axial direction. Pressure is applied in the matching direction. Therefore, the linings on the end faces of the tube are pressed together and do not separate. Furthermore, as the pressure within the packing cavity increases, the lip is pressed, so the sealing effect of the packing is improved.

[Example] This will be explained below by giving examples.

The pipes 1, 1 to be connected are as shown in FIG.
Neck flanges 2, 2 are formed at the ends, and linings 3, 3 are provided from the inner surface to the end surface. A radial groove is formed in the lining 31 of the end face of the neck flange 2, which communicates with the cavity 8 of the packing 4 from the inner surface of the pipe. Although it is sufficient to provide one groove 32 on the end face of the lining 31 of at least one tube, it is preferable to form a plurality of radial grooves at approximately equal intervals on the circumference. Also, the grooves 32, 3 of both pipes 1, 1
2 may overlap each other.

A cylindrical packing 4 having lip-shaped inward sealing surfaces formed at both ends is fitted to the outer peripheral surfaces of the neck flanges 2, 2 so as to straddle both the neck flanges 2, 2. As shown in FIGS. 1 and 2, two housings 5, 5 each having a dividing surface in the tube axis direction are attached to the outside thereof, and bolts 6,
They are integrally connected by a nut 7. An annular groove 51 is formed on the inner peripheral surface of the housing 5.
The side wall 52 has a tapered surface and closely engages with the tapered shoulder 21 of the neck flange 2 and the tapered shoulder 41 of the packing 4. By connecting in this way, the tubes 1, 1 are drawn together, the end linings 31, 31 are brought into close contact with each other, and separation of the linings 3, 31 from the tube 1 is prevented.
In addition, the groove 32 provided at the end of the lining 31 creates a gap 8 in the center of the inner circumferential surface of the packing 4 inside the pipe and on the outer surface of the pipe.
The lip of the packing 4 improves the sealing effect and achieves a reliable seal even when the pressure inside the pipe increases, and the gap 8 of the packing 4 contracts even when the pressure inside the pipe suddenly becomes negative. The lining 31 is combined with the squeezing pressure of the housing, and peeling does not occur due to pressure fluctuations.

[Effects of the invention] As explained above, the pipe connection structure according to the invention abuts the end linings of the two pipes to be connected, and communicates the inner surface of the pipe with the packing cavity, so that pressure fluid This prevents the end lining from being pushed out, or from being trapped in the gap on the inner circumferential side of the packing and pushing down the end lining. In addition, both pipes are butted together by the housing, and the end linings are also compressed and joined together, which prevents damage or peeling of the linings, and prevents vibration of the pipes even when relatively high-pressure fluid is conveyed, making it suitable. It is.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional side view showing a tube connection structure according to an embodiment of the present invention, and FIG. 2 is a partially sectional front view of the connection structure shown in FIG. 1: pipe, 2: neck flange, 21: shoulder,
3: Lining, 31: End lining, 32:
Groove, 4: Packing, 5: Housing.

Claims (1)

[Scope of utility model registration request] A shoulder 21 forms a tapered neck flange 2, 2 at the end of the pipes 1, 1 to be connected, and the pipe 1, 1
Linings 3, 3 are applied from the inner surface to the end surface of the tubes 1, 3, and at least one radial groove 32 communicating from the inside to the outside of the tubes 1, 1 is formed in at least one of the end surfaces 31, 31 of the linings 3, 3, and the ends are connected to each other. A cylindrical packing 4 with inward lips formed on the inner circumferential surfaces of both ends is attached to span the outer circumferential surfaces of the neck flanges 2, 2 of the abutted tubes 1, 1, and an annular groove 51 for accommodating the packing 4 is installed. By fastening the housings 5, 5, which have tapered surfaces complementary to the shoulders 21, 21 of the neck flange 2, to the outer periphery of the packing 4, the pipe can be closed. A pipe connecting structure characterized in that the pipes 1, 1 are connected by bringing the end surfaces 31, 31 of the linings 3, 3 into close contact with each other in a state where the insides of the linings 1, 1 and the internal space of the packing 4 are in communication.