JPH0488297A - Shutting off piping - Google Patents

Abstract

PURPOSE:To carry out the drilling work in the state where no damage is generated, by forming a hole which is long in the pipe axis direction and small in the pipe diameter direction and inserting a shut-off plate from this hole and shutting off the pipe. CONSTITUTION:A peanut shaped hole 6 is drilled on piping 1 by a drilling machine. In the state where a shut-off machine 9 is installed on an active pipe branching joint 3, a shut-off plate 7 is lowering-operated by a lowering mechanism 10, and then turned by nearly 90 deg. by a turning mechanism 102, and shifted outside the range of the peanut shaped hole 6 in the pipe axis direction by a parallel advancing mechanism 103, and fixing-supported at a shut-off position by a supporting mechanism 105. Then, at a shut-off position 15, the pressurized fluid is supplied onto the elastic member 12 of the shut-off plate 7 by a pressurized fluid feeding mechanism 104, and the elastic member 12 is formed into the shape conforming to the inner surface of the pipe, and gas leak is shut-off. Accordingly, in the shut-off work, the hole is drilled in the state where the pipe strength is not deteriorated, and the shut-off work can be effectively carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for shutting off piping used when relocating a gas pipe or cutting a valve in an active state.

[Conventional technology]

Conventionally, as a method of shutting off such piping, there is a method used for steel pipes. This involves drilling an opening with a diameter that is approximately the same as the piping diameter at right angles to the axis of the piping, and inserting a disc-shaped shutoff body that has a diameter that is approximately the same as the inside diameter of the piping into this hole so that the axis of the shutoff body and the piping This blocker is inserted with the same axis as the pipe, and the blocker is moved parallel to the pipe axis direction to block the pipe line.

[Problem to be solved by the invention]

However, if such a shutoff method is applied to a medium-pressure cast iron pipe line, for example, the strength of the pipe will be weakened due to reasons such as the large opening, so this method has not been adopted. Furthermore, even when a joint is used to perform the shutoff, there is a problem in that it is necessary to attach a fairly large joint to carry out the work for reasons of strength.

In other words, it has been impossible to proceed with construction work on such medium-pressure pipes by shutting off the pipes while they are in an active state without reducing the gas pressure.

Therefore, an object of the present invention is to provide a method for shutting off piping that can proceed with the drilling work on the piping without causing damage to the strength of the piping as much as possible, and that can also be applied to existing medium-pressure cast iron pipes, for example. It is to obtain.

[Means to solve the problem]

In order to achieve this purpose, the characteristic means of the method for shutting off piping according to the present invention is as follows. A first step of creating a hole whose diameter is approximately equal to the inner diameter of the pipe; a second step of inserting a flat, disc-shaped blocking plate into the hole from outside the pipe in a position parallel to the pipe axis; is rotated approximately 90 degrees from the insertion position in the second step, and the peripheral portion thereof is brought into pressure contact with the inner surface of the tube in a state perpendicular to the tube axis direction. be. The functions and effects thereof are as follows.

[For production]

In other words, in the piping shutoff method of the present application, the piping is shut off with a flat disc-shaped shutoff plate, and the method of moving this shutoff plate into the pipe is distinctive. That is, in the first step, a hole is drilled that is long in the tube axis direction and has a small width in the tube radial direction, and has the longest part in the tube axis direction, and in the second step, the blocking plate is drilled in the radial direction. The tube is inserted into the hole described above with the tube oriented in the axial direction of the pipe. Then, in the third step, this insertion position (
In this state, the axis of the blocking plate is substantially perpendicular to the pipe axis of the pipe. ), the shield plate is rotated approximately 90 degrees so that the shield plate is perpendicular to the pipe axis (here, the axis of the shield plate and the pipe axis of the pipe are parallel), and the circumference of the shield plate is aligned with the inner surface of the pipe. The piping is shut off by pressure contact.

〔Effect of the invention〕

Therefore, in the piping shutoff method of the present application, the shutoff plate is inserted with its longitudinal portion parallel to the pipe axis direction, and then rotated approximately 90 degrees to the shutoff state. When inserting the blocking plate into the pipe, it is sufficient to simply drill a long hole in the pipe axis direction.

That is, it is no longer necessary to drill a circular hole approximately equal to the pipe diameter as in the conventional case. Therefore, it has been possible to obtain a method for shutting off piping, which allows holes to be drilled without causing damage to the strength of the piping during the shutoff work, and which can effectively perform the shutoff work.

〔Example〕

Embodiments of the present application will be described based on the drawings. Figure 1 (a)
-(C) Connect medium pressure piping (1) in live pipe state to two locations (1a
The process from shutting off at X1b), providing a bypass pipe (2) thereto, and shutting off when relocating the pipe, etc. is shown in sequence. Here, Fig. 1 (a) shows the state in which the live pipe branch joint (3) is installed at two locations (1a) and (1b) of the piping (1) to be shut off, and Fig. 1 (b) shows ,
Figure 1 (c (a), (b)) shows whether the bypass piping (2) for bypass is installed, and where the live pipe branch joint (3) is installed, the circuit breaker (9) is shown.
) shows a plan view and a side view of the state in which it is blocked.

A description will be given below in accordance with the drawings.

FIG. 1(a) shows a medium-pressure live pipe (1) to be worked on. Ductile cast iron pipes can be mentioned as the piping material for such medium pressure pipes, and the fluid pressure is 3 kg/an" or less, which is called medium pressure B. Now, with subway construction etc., specific When relocating the piping section (work section) (5) or when cutting a valve (not shown) into the piping line, first cut the valve into the two locations (1a x 1b) that sandwich this work section. The pipe branch joint (3) is attached.Next, a drilling machine (not shown) is attached to this live pipe branch joint (3), and the drilling work proceeds.Here, this live pipe branch joint (3) is A shutter member (3a) is attached, and the construction is such that the work can proceed while maintaining the live tube state.Now, using a drilling machine (not shown), these parts (la) (I
A Daruma-shaped hole (6) as a hole is bored in b). This Daruma-shaped hole (6) has two circular holes (6a) (6a)
The hole is partially overlapped in the tube axis direction (Z), and the hole is drilled with a large distance (L) in the tube axis direction (Z) (this part is the longest part (L1)).
It is called. ) is made to be almost the same as the inner diameter (D) of the pipe (1), and the large diameter (D) in the pipe radial direction (in this case, the diameter of the circular hole) is approximately half the inner diameter of the pipe. It is structured as follows. This dimensional relationship is based on the longitudinal direction (7a) of the blocking plate (7), which will be described later, and the tube axis direction (Z).
The design is such that it can be inserted into the tube while maintaining the same posture.

As described above, when the Daruma-shaped hole (6) is employed, it can be easily processed using existing equipment. The step of performing this drilling work is called the first step.

After such drilling work, the above-mentioned live pipe branch joint (3) is equipped with a bypass pipe connection part (8) instead of a drilling machine (not shown).
A circuit breaker (9) is installed. In the replacement operation, the aforementioned shutter member (3a) is effectively used. FIG. 1 (+) shows a state in which the bypass pipe connecting portions (8) of two circuit breakers (9) are connected by a pressure-resistant flexible hose. In this state, the main pipe to be worked on has not yet been shut off.

Next, the circuit breaker (9) is installed at two locations (1aX1b) on the main pipe.
This section explains the operation to shut off. Figure 1 (c(a))
The first drawing shows the part to be blocked (10) viewed from above.
The figure (c(b)) shows the same part (10) viewed from the side.

First, the schematic configuration of this circuit breaker (9) will be explained.

This breaker (9) is configured so that it can be connected to its bottom (9b) or the above-mentioned live pipe branch joint (3), and the above-mentioned breaker plate (7) is connected in its longitudinal direction (7a). The lowering mechanism (101) moves the shielding plate (7) vertically while keeping it in the tube axis direction (Z), and the shielding plate (7) is moved approximately 90 degrees with the center of the shielding plate (7) aligned with the tube axis (Z). It is configured to include a rotation mechanism (102) that rotates the shield plate (7), and a translation mechanism (103) that moves the shield plate (7) in parallel within the pipe.

The blocking plate (7) itself is constructed by sandwiching an elastic member (12) made of rubber or the like between a pair of disc members (11) formed to have a diameter slightly smaller than the inner diameter of the tube. Furthermore, this elastic member (12) is provided with a pressurized fluid supply mechanism (104) that supplies pressurized fluid such as air, water, oil, etc. from the circuit breaker main body (13) side to the inside thereof. In addition, as shown in Fig. 1 (c (b)), a blocking plate (
7) When the circuit breaker itself is in the completed state, the circuit breaker main body (13)
From the side, the above-mentioned lowering mechanism (101) and rotating mechanism (102)
), the support mechanism (1) connected to the translation mechanism (103)
05) is configured to restrict and support movement.

The shutoff operation will be explained step by step below.

With the breaker (9) attached to the above-mentioned live pipe branch joint (3), the lowering mechanism (101) allows the breaker plate (7) to maintain its longitudinal direction (7a) in the pipe axis direction (Z). , is operated downward. This process is called the second process. When the center of the blocking plate (7) approximately coincides with the tube axis (Z), the blocking plate (7) is rotated approximately 90 degrees by the rotation mechanism (102), and is rotated with respect to the tube axis direction (Z). Therefore, it is considered to be a right angle.

Then, the translation mechanism (103) further moves the tube axis direction (Z
) is moved out of the range of the Daruma-shaped hole (6) and is fixedly supported at the blocking position (15) by the support mechanism (105). In Figure 1 (c (a), (b)), the solid line shows the blocking plate (7) in the completed state of blocking, and the solid line shows the blocking plate (7) when the blocking is activated.
The states of (the original position of the blocking plate (7) and the lowered position of the blocking plate (7)) are shown by two-dot chain lines. Now, at the blocking position (15), pressurized fluid is supplied from the above-mentioned pressurized fluid supply mechanism (104) to the elastic member (12) provided on the blocking plate (7). By this operation, the elastic member (1
2) is shaped to follow the inner surface of the tube, making it possible to block gas leakage. This step is called the third step. Now, in the structure of the present application, most of the gas pressure is received by the disc member (11) supported by the support mechanism (105), and the elastic member (12) seals the disc member (11) and the inner wall surface of the pipe. However, the structure is such that the uke is held. Furthermore, in the present application, the insertion and fixation of the shutoff plate (7) is performed by a unique mechanism, so it can be used to shut off medium pressure piping (1), and the piping does not require large holes in the piping. We were able to obtain a method for blocking this.

[Another example]

In the above-mentioned embodiment, an example was shown in which the Daruma-shaped holes (6) were bored in the live pipe, but the longitudinal direction (7a) of the disc-shaped blocking plate (7) having the shape as described above (this is approximately equal to the inner diameter of the pipe.) Any shape may be adopted as long as the hole can be inserted in alignment with the pipe axis direction (Z). For example, a rectangular hole can be considered.

Furthermore, a pair of disk members (11) are used as the blocking plate (7).
An elastic member (12) is sandwiched between the elastic member (12).
) has been described in which the elastic member (12) is expanded by supplying fluid, but the disc member is formed from an integral solid disc;
It is also possible to have a structure in which a tube is formed on the outer periphery of an elastic member.

Additionally, a purge passage (16) as shown in Figure 2 may be provided between the cutoff plate (7) and the breaker body (13).If such a structure is adopted, the cutoff operation can be performed reliably. This makes it possible to easily purge the gas pressure in the working area and check for excess gas.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings by the reference numerals.

[Brief explanation of drawings]

The drawings show an example of the method for shutting off piping according to the present invention, FIG. 1 (4) (T1) (c) is a schematic diagram of the shutoff process, and FIG. It is a figure which shows another Example. (1)... Piping, (6)... Hole, (7
)......Break plate, (D)...Inner diameter, (L
1)...Longest part, (Z)...Pipe axis direction. Figure 1 (b)

Claims (1)

[Claims] 1. On the side surface of the pipe (1), the longest part ( a first step of providing a hole (6) with a diameter (L1) approximately equal to the inner diameter (D) of the pipe (1); and a flat shielding plate (7) in the shape of a disk inside the hole (6); A second step of inserting from outside the tube in a posture parallel to the axial direction (Z), and rotating the blocking plate (7) approximately 90 degrees from the insertion position in the second step, and inserting it in the tube axial direction (Z). A method for shutting off a pipe, the method comprising: a third step of bringing the peripheral portion into pressure contact with the inner surface of the pipe while the pipe is in a right-angled state. 2. The piping according to claim 1, wherein the hole (6) is a daruma-shaped hole formed from two circular holes (6a) and (6b) of the same diameter that partially overlap in the pipe axis direction (Z). How to shut off.