Piping system and uninterrupted flow method

Abstract

To provide a piping system and an uninterrupted flow method which can reduce cost by reducing a nominal diameter of a newly-installed piping element than existing pipes.SOLUTION: The piping system includes: a main pipe part (10) which is a passage for fluid; a branch pipe part (11) projecting in a radial direction (R) of the main pipe part and having a first flange (11F) at a tip end part thereof; water stop means (4) for selectively stopping a flow of fluid flowing from the main pipe part to the branch pipe part; a piping element (N) connected to the branch pipe part and having a second flange (NF) having a diameter smaller than that of the first flange; and an adapter (A) positioned between the first flange and the second flange, having a lower surface being fastened to the first flange via a plurality of fastening members, and having an upper surface being fastened to the second flange via a plurality of second fastening members. The second fastening members are positioned on an inner side from the first fastening members in a radial direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a piping system and a continuous flow method.

Background Art

[0002] A method is known in which the fluid in the branch pipe portion of an existing T-shaped pipe is frozen with a liquid refrigerant or the like, and the flow of the fluid is blocked with an ice plug to replace the piping element (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0004] In the invention of Patent Document 1, the existing piping element and the newly installed one have the same nominal diameter, which may be uneconomical.

[0005] Air valves are generally installed in the branch pipe portion of a T-shaped pipe. This air valve is for discharging a huge amount of air filling the long pipeline after piping the long pipeline. Therefore, a relatively large air valve is arranged.

[0006] Once the air in the pipeline is completely discharged and the pipeline is filled with a predetermined amount of water or oil, the large air valve is unnecessary, and a small nominal diameter air valve for maintenance is sufficient.

[0007] However, in Patent Document 1, the air valve is replaced with one having the same nominal diameter as the existing one, which is uneconomical.

[0008] In addition, the pipeline that requires replacement of the air valve is old. Therefore, the distance from the apex of the main pipe to the ground is small, and the height of the ceiling of the valve chamber is low. Therefore, when installing the air valve, due to height restrictions, a repair valve cannot be inserted, and in some cases, the air valve is installed in the branch pipe portion of the main pipe via a reducer.

[0009] In this case, when the newly installed air valve deteriorates, it is necessary to carry out construction again using the freezing method.

[0010] On the other hand, Patent Document 3 discloses an adapter flange for reducing the nominal diameter. However, it does not disclose replacing the nominal diameter of the installed fire hydrant with a smaller one.

[0011] An object of the present invention is to provide a piping system and a non-stop flow method that reduce the height from the top of the newly installed piping element to within the valve chamber by making the nominal diameter of the newly installed piping element smaller than that of the existing one so that it fits within the valve chamber and also reduce costs.

[0012] The non-stop flow method of the present invention is a non-stop flow method for replacing an existing piping element 12 installed in a branch pipe portion 11 of a T-shaped pipe portion 1 having an existing pipeline with a main pipe portion 10 and a branch pipe portion 11 protruding in the radial direction R of the main pipe portion 10 with a newly installed piping element N, and a water stop step of stopping the fluid L in the branch pipe portion 11 while the fluid L is flowing in the main pipe portion 10 of the T-shaped pipe portion 1; a removal step of removing the existing piping element 12 while the fluid L is stopped; and a step of attaching a newly installed piping element N having a nominal diameter smaller than that of the existing piping element 12 to the branch pipe portion 11 while the fluid L is stopped.

[0013] According to the present invention, since a newly installed piping element N having a nominal diameter smaller than that of the existing piping element 12 is installed, the cost is reduced.

[0014] Preferably, in a state where the fluid L is frozen, a first coupling step of coupling an adapter A having a lower surface S1 that conforms to the flange 11F of the branch pipe portion 11 and an upper surface S2 that conforms to the flange NF of the newly installed pipe element N to the branch pipe portion 11; The method further includes a second coupling step of coupling the flange NF of the newly installed pipe element N to the upper surface S2 of the adapter A.

[0015] In this case, by using the adapter A, a standard product can be used as it is as the newly installed pipe element N, and the cost can be reduced.

[0016] More preferably, the adapter A is an annular plate-shaped flange.

[0017] By using a plate-shaped flange as the adapter A, it is easier to fit into the valve chamber compared to using a reducer that is long in the pipe axis direction.

[0018] Preferably, the existing pipe element 12 is an existing repair valve 121 and an air valve 122, and the newly installed pipe element N is a repair valve N1 and an air valve N2 having a smaller nominal diameter than the existing repair valve 121 and air valve 122.

[0019] In this case, since the nominal diameters of the newly installed repair valve and air valve after construction are smaller, the cost is reduced, and the height to the top of the air valve is reduced, making it more compact.

[0020] Preferably, the existing pipe element 12 is an existing air valve 122, and the newly installed pipe element N is a repair valve N1 and an air valve N2 having a smaller nominal diameter than the existing air valve 122.

[0021] In this case, since the newly installed nominal diameter is smaller, even if a repair valve is inserted between the air valve and the branch pipe portion, the height to the top of the air valve can be kept small and it can be accommodated in the valve chamber, so a repair valve can be inserted.

[0022] In addition, the piping system according to the present invention includes a main pipe portion that serves as a fluid flow path, a branch pipe portion that protrudes in the radial direction of the main pipe portion and has a first flange at its tip end, a water stop means for selectively stopping the flow of fluid flowing from the main pipe portion to the branch pipe portion, a piping element that is connected to the branch pipe portion and has a second flange with a smaller diameter than the first flange, and an adapter that is positioned between the first flange and the second flange, the lower surface of which is fastened to the first flange via a plurality of first fastening members, and the upper surface of which is fastened to the second flange via a plurality of second fastening members. The second fastening member is located radially inside the first fastening member.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Examples

[0024] Hereinafter, examples of the present invention will be described with reference to the drawings. Prior to the description of this method, existing and new piping structures will be described.

[0025] Figure 4 shows the existing piping structure.

[0026] In Figure 4, the T-shaped pipe section 1 of the existing pipeline has a main pipe section 10 and a branch pipe section 11 protruding in the radial direction R of the main pipe section 10. An existing piping element 12 is installed in the branch pipe section 11 of the T-shaped pipe section 1.

[0027] As will be described later, the existing piping element 12 is removed from the existing pipeline.

[0028] In the case of this example, the existing branch pipe section 11 consists of a branch section 11B branched from the main pipe section 10 and a reducer (diameter-reducing pipe) 11R flange-jointed to this branch section 11B.

[0029] Also, in the case of this example, the existing piping element 12 consists of an existing repair valve 121 and an air valve 122. The repair valve 121 is flange-jointed to the reducer 11R, and the air valve 122 is flange-jointed to the repair valve 121.

[0030] Figures 1 to 7 show Example 1.

[0031] Figure 1 shows the piping structure after the construction is completed.

[0032] The existing piping element 12 in Figure 4 is replaced with the newly installed piping element N in Figure 1.

[0033] In Figure 1, the newly installed piping element N is a repair valve N1 and an air valve N2 with a smaller nominal diameter than the existing repair valve 121 and air valve 122 (Figure 4).

[0034] An adapter A is inserted between the reducer 11R in Figure 1 and the newly installed repair valve N1. As shown in Figures 2 and 3, the adapter A is an annular plate-shaped flange and has a lower surface S1 in Figure 2 that fits the flange 11F of the branch pipe section 11 in Figure 1 and an upper surface S2 in Figure 2 that fits the flange NF of the newly installed piping element N in Figure 1.

[0035] This construction method is a non-stop flow method. While the fluid L is flowing in the main pipe portion 10 of FIG. 4, the following respective steps are executed.

[0036] Prior to the formation of the ice plug, a framing step is executed as shown in FIG. 5(a). In the framing step of FIG. 5(a), a mold-like frame 3 is assembled to the reducer 11R so as to surround the reducer 11R. The frame 3 may be made of, for example, expanded polystyrene, and the gap between the frame 3 and the reducer 11R may be filled with a wet putty.

[0037] In the filling step of FIG. 5(b), a refrigerant 4 such as liquid nitrogen is poured into the frame 3 to fill the frame 3 with the refrigerant 4 for freezing. The fluid L in the reducer 11R is frozen by this refrigerant 4.

[0038] That is, a freezing step is executed to freeze a part of the fluid L in the branch pipe portion 11 while the fluid L is flowing in the main pipe portion 10 of FIG. 4. In the case of this example, the part where the fluid L is frozen may be at least a part within the branch pipe portion 11.

[0039] In the frozen state, as shown in FIG. 6(a), the old piping element 12 is removed.

[0040] After this removal, as shown in FIG. 6(b), a first coupling step is executed to couple the adapter A to the flange 11F of the reducer 11R while the fluid L is frozen. After this, a second coupling step is executed to couple the flange NF of the repair valve N1, which is a part of the new piping element N of FIG. 7, to the upper surface S2 of the adapter A.

[0041] Thereafter, an air valve N2 is attached onto the repair valve N1 of FIG. 7(b). Note that since the repair valve N1 is closed during this attachment, the frozen state may be released.

[0042] After the replacement, the refrigerant 4 is recovered and the frame 3 is removed.

[0043] In this way, the existing piping element 12 shown in FIG. 4 is replaced with the new piping element N shown in FIG. 1.

[0044] Figures 1 and 7 to 10 show Example 2.

[0045] Figure 1 shows the piping structure after the construction is completed.

[0046] The existing piping element 12 in Figure 8 is replaced with the newly installed piping element N in Figure 1.

[0047] In Figure 1, the newly installed piping element N is a repair valve N1 and an air valve N2 with a smaller nominal diameter than the existing air valve 122 (Figure 8).

[0048] An adapter A is inserted between the reducer 11R in Figure 1 and the newly installed repair valve N1. As shown in Figures 2 and 3, the adapter A is an annular plate-shaped flange, having a lower surface S1 in Figure 2 that fits the flange 11F of the branch pipe portion 11 in Figure 1, and an upper surface S2 in Figure 2 that fits the flange NF of the newly installed piping element N in Figure 1.

[0049] This construction method is a non-stop flow method, and the following steps are executed while the fluid L is flowing in the main pipe portion 10 in Figure 8.

[0050] Prior to the formation of the ice plug, a framework process is executed as shown in Figure 9(a). In the framework process of Figure 9(a), a formwork-like frame 3 is assembled to the reducer 11R so as to surround the reducer 11R. The frame 3 may be made of, for example, expanded polystyrene, and the gap between the frame 3 and the reducer 11R may be filled with a wet putty.

[0051] In the filling process of Figure 9(b), a refrigerant 4 such as liquid nitrogen is poured into the frame 3 to fill the frame 3 with the refrigerant 4 for freezing. The fluid L in the reducer 11R is frozen by this refrigerant 4.

[0052] That is, a freezing process is executed to freeze a part of the fluid L in the branch pipe portion 11 while the fluid L is flowing in the main pipe portion 10 in Figure 8. In the case of this example, the part where the fluid L freezes may be at least a part within the branch pipe portion 11.

[0053] In the frozen state, as shown in Fig. 10(a), remove the old piping element 12.

[0054] After this removal, as shown in Fig. 10(b), perform a first coupling step of coupling the adapter A to the flange 11F of the reducer 11R with the fluid L frozen. After this, perform a second coupling step of coupling the flange NF of the repair valve N1, which is a part of the newly installed piping element N in Fig. 7, to the upper surface S2 of the adapter A.

[0055] After that, attach the air valve N2 onto the repair valve N1 in Fig. 7(b). Note that since the repair valve N1 is closed during this attachment, the frozen state may be released.

[0056] After the replacement, recover the refrigerant 4 and remove the frame 3.

[0057] In this way, the existing piping element 12 shown in Fig. 8 is replaced with the newly installed piping element N in Fig. 1.

[0058] In the present invention, when attaching the newly installed piping element N, the adapter A, the repair valve N1, and the air valve N2 may be pre-assembled (sub-assembled) integrally in advance, and then these sub-assembled newly installed piping elements N may be attached to the reducer 11R.

[0059] Also, the part forming the ice valve may be the branch portion 11B instead of the reducer 11R. Further, the position of the frame 3 arranged on the reducer 11R may be set higher than in this embodiment.

[0060] Also, the adapter A may have a structure like a reducer whose inner diameter becomes smaller upward.

[0061] Also, prior to the freezing step in Fig. 5(b), the bolt nuts fastening the reducer and the repair valve 121 may be replaced in advance.

[0062] Furthermore, a tapping screw as a locking tool engaging with the ice valve may be provided in the reducer in advance.

[0063] In each of the above embodiments, the freezing process is used as the water stop means, but other well-known means (for example, providing a valve in the branch pipe portion, etc.) may be used to stop the water.

Industrial Applicability

[0064] The construction method of the present invention can be adopted for pipelines such as crude oil in addition to pipelines for water supply.

Explanation of Reference Numerals

[0065] 1: T-shaped pipe portion 10: Main pipe portion 11: Branch pipe portion 11B: Branch portion 11R: Reducer 11F, NF: Flange 12: Existing piping element 121: Repair valve 122: Air valve 3: Frame 4: Refrigerant A: Adapter S1: Lower surface S2: Upper surface N: New piping element N1: Repair valve N2: Air valve L: Fluid R: Radial direction

Claims

1. A main pipe section which serves as a fluid flow path; a branch pipe portion that projects in a radial direction of the main pipe portion and has a first flange at a tip end thereof; a water stopping means for selectively stopping a flow of fluid flowing from the main pipe section to the branch pipe section; a piping element connected to the branch pipe portion and having a second flange having a diameter smaller than that of the first flange; an adapter located between the first flange and the second flange, the lower surface of which is fastened to the first flange via a plurality of first fastening members and the upper surface of which is fastened to the second flange via a plurality of second fastening members; A piping system, wherein the second fastening member is located radially inward relative to the first fastening member.

2. In claim 1, The piping system, wherein the adapter is an annular plate flange.

3. In claim 2, The adapter has an inner diameter that decreases toward the top.

4. A method for replacing an existing piping element installed in a branch pipe portion of the T-shaped pipe portion of an existing pipeline with a new piping element, the method comprising the steps of: a water stopping step of stopping the flow of fluid in the branch pipe section while the fluid is flowing in a main pipe section of the T-shaped pipe section; a removal process of removing the existing piping element while the flow of the fluid is stopped; and attaching a new piping element having a smaller nominal diameter than the nominal diameter of the existing piping element to the branch pipe portion while the flow of the fluid is stopped. a first coupling step of coupling an adapter having a lower surface that fits a flange of the branch pipe section and an upper surface that fits a flange of the newly installed piping element to the branch pipe section while the flow of the fluid is stopped; The uninterrupted flow construction method further comprises a second joining step of joining a flange of the new piping element to an upper surface of the adapter.

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