JP4416158B2 - How to update existing piping - Google Patents

Description

  The present invention relates to a method for updating existing pipes such as aging sanitary equipment pipes for air supply and drainage and air conditioning pipes in existing buildings to new pipes, and to a piping method for changing the existing pipes mainly to stainless steel pipes.

  Renewal work that replaces aging existing pipes in existing buildings is conventionally done by extracting existing pipes that penetrate concrete slabs and walls, and then connecting them through the new pipes. It was the law. At this time, the material of the new pipe to be renewed is the same or higher than that of the existing pipe, and recently, there are many cases where stainless steel pipes that are thin, lightweight, and have excellent corrosion resistance are used. .

On the other hand, regarding a method of inserting a new pipe into an existing old pipe, JP-A-2001-280538, JP-A-2003-35381, and the like have been proposed as a method of inserting and laying the new pipe into the old old pipe. In these methods, the new pipe can be pushed in even if there is a curved part of the existing pipe, but the use is limited because a thermoplastic pipe is used as the new pipe, and more expensive installation equipment is required. Therefore, it is not easy to implement.
JP 2001-280538 A JP 2003-35381 A

  In the above renewal method, in order to remove existing pipes buried in concrete slabs or walls, the concrete and walls around the buried part of the existing pipes are chiseled with an air excavator etc., and then the existing pipes are cut. Must be extracted. This renewal method has the following problems.

(1) The chipping work takes a long time and the chipping work in a narrow pipe shaft is difficult.
(2) The chiseling noise is loud and noise pollution occurs.
(3) A large amount of concrete dust and dust generated during the chiseling work appears.
(4) After the new pipe is completed, it is necessary to refill the voids of the new pipe through the concrete slab or wall with mortar.
(5) It is necessary to remove all existing pipes and heat insulation materials, and the amount of waste materials to be disposed of is large, resulting in a large amount of waste material treatment costs.
As a result, the cost of the renewal work becomes very high.

  In the present invention, in the construction of renewing an aged existing pipe to a new pipe, for example, a stainless steel pipe, the existing pipe buried in the concrete slab or wall is cut without being removed, and the remaining existing pipe is cut. The problems (1) to (5) are solved by inserting a new pipe having an outer diameter smaller than the inner diameter of the existing pipe into the pipe and performing the front and rear piping work. Accordingly, an object of the present invention is to provide a method for renewing existing piping that is lower in cost than the conventional construction method and that completes the construction period for renewal work in a short time.

The method for renewing an existing pipe according to the present invention is that when an old existing pipe in an existing building is updated with a new metal pipe, the existing pipe is buried without removing a portion of the existing pipe buried in a concrete slab or a wall. The insertion pipe part is embedded on the upper floor so that the insertion pipe part is not temporarily protruded from the lower end surface of the embedded part of the existing pipe when the front and rear of the part is cut and the new insertion pipe part is pushed in. After protruding from the upper end surface of the part and tightening the insertion pipe part with a ready-made pipe support band or the like to prevent dropping, connect the newly installed intermediate pipe parts arranged above and below the insertion pipe part This is what pipes are constructed. In this update method, the newly installed insertion tube and the intermediate tube have a smaller outer diameter than the existing tube, and the newly inserted tube can be inserted so as to match the tube axis direction of the existing tube. It is the following length.

In an example of the renewal method of the present invention, the outer diameter of the newly installed insertion tube portion to be pushed into the embedded portion of the existing tube and the outer diameter of the newly installed intermediate tube portion arranged above and below the insertion tube portion are the same diameter. It is . Nozomu Mashiku is new metal tube pressed into the aging existing pipe is stainless steel.

  The renewal method of the present invention is a plumbing method for renewing an aging existing pipe in an existing building with a new metal pipe. Examples of existing buildings include concrete buildings such as buildings and condominiums, steel buildings, general wooden houses, water towers, etc. it can.

  About the update method of this invention, the example which updates the existing water supply standpipe in a concrete apartment house to a stainless steel pipe is demonstrated concretely.

  In many cases, aging existing pipes use galvanized steel pipes, vinyl chloride lining steel pipes, or polyethylene powder-coated steel pipes as water supply pipes. The entire inner surface of a galvanized steel pipe is corroded, and in vinyl chloride lined steel pipes and polyethylene powder-coated steel pipes, the parts that are not subjected to pipe end corrosion protection at the joint connection parts are corroded. Will occur. When rust occurs, red water comes out from the water supply pipe, or a hole is formed in the water supply pipe and the water leaks.

  If the existing pipe is a vinyl chloride lined steel pipe or polyethylene powder coated steel pipe, even if the insertion pipe part of the stainless steel pipe is directly pushed in, the stainless steel pipe and the pipe material of the existing pipe which is a different metal are not in direct contact. In this case, it is not necessary to cover the insertion tube portion with a plastic insulating sleeve.

On the other hand, if the existing pipe is a galvanized steel pipe, it is desirable to push in after inserting a plastic insulating sleeve such as a poly sleeve on the insertion pipe portion so as not to directly contact the insertion pipe portion of the stainless steel pipe to be pushed in. In addition, when the existing pipe is a galvanized steel pipe, a large rust hump adheres to the inner surface of the pipe, which may cause a problem in pushing the insertion pipe portion. At this time, it is necessary to remove rust humps from the galvanized steel pipe in advance.

  For example, when water is supplied to 14 households with a single water supply standpipe, the span (floor height) of the concrete slab is 2700 mm. For existing polyvinyl chloride lined steel pipes with a nominal diameter of 50A, existing stainless steel pipes are replaced with existing stainless steel pipes using JIS G 3448 general pipe stainless steel pipes that are thin and have a large actual inner diameter. Table 1 below shows which size of stainless steel pipe can be pushed into an existing vinyl chloride lined steel pipe.

When cutting while leaving the existing standing pipe buried in the concrete slab, if the cutting is performed leaving 1350mm which is 1/2 of the span (floor height), the distance between the upper and lower cutting end faces will be 1350mm. The stainless steel pipe insertion pipe portion (length 1350 mm) can be inserted so as to match the pipe axis direction of the existing pipe, and the amount of waste pipe material to be removed is reduced. At this time, if the cutting is performed while leaving a length exceeding 1/2 of the span, the interval between the upper and lower cutting end faces becomes less than 1350 mm, so that the insertion tube portion exceeding the length of 1350 mm matches the tube axis direction of the existing tube. it becomes impossible to insert such.

  In addition, if a large number of existing standing pipes are left and cut, the thermal insulation can be used more effectively while leaving the heat insulating material as it is, so that the merit in the renewal work is greatly increased. Therefore, the cutting length of the existing pipe is ½ or less of the span (floor height) and is as long as possible while also considering the connection allowance according to the type of joint to be connected to the intermediate pipe portion of the inserted stainless steel pipe It is preferable to leave the dimensions.

  Referring to Table 1, if the existing pipe that is a water supply pipe is a vinyl chloride lining steel pipe having a nominal diameter of 50A, the outer diameter of the inserted stainless steel pipe is 48.6 mm, and the inner diameter of the inserted pipe is Becomes thinner than the inner diameter of the vinyl chloride lined steel pipe. In response to this problem, the design of water supply pipes more than 15 years ago that required replacement of existing pipes was mostly based on the equipment water supply load unit method developed by Mr. Hunter in the United States. It is calculated more than the amount of water used, and the piping size is designed to be larger accordingly. For example, if the instantaneous maximum water supply amount to supply water to 14 households is calculated by Mr. Hunter's device water supply load unit method, it is about 230 liters / minute, and when the flow rate is set to 1.0 to 2.0 m / second, the pipe size is 50A ~ 60A is required. Examining the actual situation, most of the water supply piping of the same scale is actually 50A.

  On the other hand, research on the actual usage of water supply is also progressing today, and when the water supply usage is calculated by one of the currently proposed methods for calculating the instantaneous maximum water supply, it is about 112 liters / minute. With regard to the amount of water used, when a 40Su (outer diameter = 42.7mm) stainless steel pipe is used, the flow rate is about 1.5m / sec. When a 50Su (outer diameter = 48.6mm) stainless steel pipe is used, the flow rate is About 1.1 m / sec. Therefore, a stainless steel pipe used as a new pipe can be used at 40 Su or 50 Su.

  At this time, if the new metal pipe is a stainless steel pipe, the stainless steel pipe is not only rust-resistant but also has a friction resistance on the inner surface of the pipe compared to the existing existing pipes such as vinyl chloride lining steel pipe and polyethylene powder coated steel pipe. Less cavitation resistance. For this reason, with stainless steel pipes, the maximum flow rate is 3.5 m / sec. Even in the case of a small diameter, about 2.0 m / sec is appropriate. Therefore, the pipe diameter can be easily reduced to a small diameter, and the present invention is updated. It is clear that the method is feasible.

  As shown in FIG. 2, the insertion pipe portion 10 such as a stainless steel pipe must be temporarily held at the position of the existing pipe during the renewal work. As a temporary holding method, the insertion pipe portion 10 of the stainless steel pipe to be renewed is protruded upward from the upper end surface of the embedded portion 7 of the existing pipe on the upper floor side, and the insertion pipe portion is supported on the pipe of the ready-made product. Tighten with band 14 or the like. As a result, the insertion tube portion 10 is temporarily held at the upper end portion of the embedded portion 7 of the existing tube, and can be easily prevented from falling. With this temporary holding, it is not necessary to arrange plumbers on the upper and lower floors, and renewal work can be achieved by one plumber. As a matter of course, the ready-made piping support band used for temporary holding can be repeatedly used.

  As shown in FIG. 3, grooving (groove) processing is performed on each pipe end, and both pipe ends are tightened with a Victorian pipe joint 20 to connect each insertion pipe 10 and the intermediate pipe 12. And connect. Such a connection is a press type as exemplified in FIGS. 4 (1) and (2), a one-touch type as shown in FIGS. 5 (1) and (2), and as shown in FIGS. 6 (1) and (2). You may carry out using couplings, such as a nut type.

  The existing pipe renewal method according to the present invention can be renewed to a new pipe such as a stainless steel pipe without removing the existing pipe buried in a concrete slab or a wall, so that there is no need for a chipping operation. The removal of the heat insulation material is very beneficial because it reduces the amount of waste material disposal. According to the renewal method of the present invention, it is possible to renew the pipe at a low cost and in a short construction period.

  In the renewal method of the present invention, when a Victorian pipe joint is used to connect the insertion pipe part and the intermediate pipe part of the stainless steel pipe, the groove end (groove) is simply applied to each pipe end part as compared with welding. It is preferable because the connection is easy, the connection portion does not fall out, and the deflection and expansion / contraction of the tube can be absorbed. Also, if the upper end of the insertion tube is tightened with an off-the-shelf piping support band, the stainless steel tube insertion tube is temporarily held by the upper end of the embedded portion of the existing tube, so that it can be prevented from falling. It is economical because renewal work can be achieved.

  Next, the present invention will be described based on examples, but the present invention is not limited to the examples. In FIG. 1, the example of the location which replaces the existing water supply pipe 2 in the concrete apartment house 1 with a stainless steel pipe is shown. In the concrete apartment house 1, water is supplied to 14 households by one system of water supply standpipe 2, and the span of the concrete slab 3 is 2700 mm.

  In this renewal work, the concrete slab 3 is cut at a position a that is 300 mm from the upper surface 5 and a position b that is 950 mm below the upper surface 5. As a result, the embedded portion 7 of the existing pipe having a total length of 1250 mm is left buried in the concrete slab 3, and the intermediate standing pipe portion 8 is removed 1450 mm. Since the existing pipe is a vinyl chloride lined steel pipe having a nominal diameter of 50A, the insertion pipe portion 10 (FIG. 2) of the stainless steel pipe to be pushed into the existing pipe is defined as 50 Su (outer diameter 48.6 mm) from Table 1 above. The length of the insertion pipe portion 10 is 1350 mm, which is 100 mm longer than the buried portion 7 of the existing pipe having a length of 1250 mm remaining in the concrete slab 3 and is 100 mm longer than the buried portion 7 of the existing pipe. The existing piping can be renewed by connecting the intermediate pipe portion 12 (FIG. 2) of a stainless steel pipe having a length of 1350 mm up and down.

Next, the construction procedure of the update work will be described based on FIG.
(1) With respect to the existing water supply standpipe 2 buried in the concrete slabs 3 on the upper and lower floors, the intermediate standpipe part 8 (see FIG. 1) is left by a handy type electric saw etc. that does not use fire, leaving a predetermined buried part 7. ) And remove it.

(2) In the buried pipe portion 7 of the existing pipe in the concrete slab 3 on the upper floor, the insertion pipe portion 10 of the stainless steel pipe, which is longer than this dimension so that it can be connected by a joint, is pushed in so as to coincide with the pipe axis direction. The insertion tube portion 10 is temporarily held so as not to temporarily protrude from the lower end surface of the embedded portion 7. In order to temporarily hold the insertion pipe 10, the insertion pipe is protruded upward from the upper end surface of the embedded portion 7 of the existing pipe that protrudes to the upper floor side, and the insertion pipe is provided with the pipe support band 14 of the ready-made product. Tighten with to prevent falling.

  (3) Insert the intermediate pipe portion 12 ′ having a branch branch for supplying water to each dwelling unit on the insertion pipe portion 10 and the intermediate pipe portion 12 on the lower floor that has already been constructed. After this, the insertion pipe portion 10 ′ pushed and temporarily held in the buried portion 7 of the existing pipe on the upper floor is pulled down to be aligned with the lower intermediate pipe portion 12 ′.

  (4) In order to connect each insertion pipe part 10 and the intermediate pipe part 12, as shown in FIG. 3, a grooving (groove) process is given to each pipe end part. At this time, the gasket 22 of the Victorian pipe joint 20 is fitted into the annular grooves 16 and 18 at the pipe ends of the insertion pipe part 10 and the intermediate pipe part 12, and the housing 24 is put on and tightened with the bolt-nut 26. The new stainless steel pipe support can be either the existing pipe attached to the wall as it is, or using a band (not shown) or the like, and fastened together with the existing pipe buried portion 7 left on the concrete slab 3. Can also be fixed.

  (5) After the connection of the new stainless steel pipe is completed, performing a leak test such as a water pressure test is the same as general piping.

  (6) After the leak test is completed, the gap between the buried portion 7 of the existing pipe and the insertion pipe portion 10 of the stainless steel pipe is filled with a non-flammable material such as rock wool or a flame-retardant foaming agent and backfilled. . Finally, a heat insulating material (not shown) is wound around the exposed insertion tube portion 10 and the intermediate tube portion 12 of the stainless steel pipe, and in order to prevent condensation, the remaining embedded portion 7 is connected to the heat insulating material. Complete joint repairs. As a result, it is possible to prevent the vibration of the new stainless steel pipe through which the fluid flows from being transmitted to the embedded portion 7 of the existing pipe by filling the obvious space between the newly installed stainless steel pipe and the existing pipe embedded portion 7.

  Next, FIG. 7 shows a second embodiment of the present invention. In this embodiment, the pipe diameter of the buried portion 30 of the existing pipe buried in the concrete slab 28 is small, and the diameter of the stainless steel pipe pushed into the pipe may be smaller than the value required for design. In such a case, only the insertion pipe portion 32 to be pushed into the embedded portion 30 of the existing pipe is made to have a small diameter, and the pipe size of the intermediate pipe section 34 on the way is made one size or more larger than the diameter necessary for design. As a result, the pressure loss in the small-diameter insertion pipe portion 32 inserted into the existing pipe can be compensated by the large-diameter intermediate pipe portion 34.

  In this embodiment, the length of the buried portion 30 of the existing pipe buried in the concrete slab 28 is set to the minimum length that can be cut, and the portion that is narrower than the diameter necessary for the design is made as short as possible. In other words, the overall pressure loss can be further reduced by making the length of the intermediate pipe portion 34 that is one size or more larger than the required diameter in design as much as possible.

  Therefore, if the present embodiment is the same piping mode as in the first embodiment, the existing pipe embedded in the concrete slab 28 is cut by adding a connection allowance, leaving 400 mm, and this is the length of the embedded portion 30 of the existing pipe. Become. In this case, 2300 mm of the intermediate stand tube portion is removed. The construction of the renewal work is the same procedure as in the first embodiment.

It is a schematic longitudinal cross-sectional view which partially shows about the location which replaces the existing water supply standpipe in a concrete apartment house with a new metal pipe. It is a schematic longitudinal cross-sectional view which shows the example of construction in the part of FIG. 1 partially. (1) is a partially enlarged longitudinal sectional view and (2) is an end view of the electric pipe joint used in the present invention. About a press type joint, (1) is a longitudinal section and a side view, and (2) is a longitudinal section and a side view of another joint. Regarding the one-touch joint, (1) is a longitudinal sectional view, and (2) is a side face, a longitudinal section and an end view of another joint. About a nut type joint, (1) is a longitudinal section and a side view, and (2) is a side, longitudinal section and end view of another joint. It is a schematic longitudinal cross-sectional view similar to FIG. 2 which shows another Example of this invention.

Explanation of symbols

2 Existing water supply standpipe 3 Concrete slab 7 Buried part of existing pipe 8 Intermediate standpipe part 10 Insertion pipe part 12 Intermediate pipe part 20 Victorian pipe joint

Claims (3)

  When renewing an aging existing pipe in an existing building with a new metal pipe, the existing pipe is cut before and after the existing pipe buried in the concrete slab or wall, without removing the existing pipe. So that the insertion tube portion does not temporarily protrude from the lower end surface of the embedded portion of the existing pipe when the portion is pushed in, the insertion tube portion protrudes above the upper end surface of the embedded portion on the upper floor side, The insertion pipe part is tightened with a ready-made pipe support band, etc. to prevent it from dropping, and then pipe construction is performed by connecting new intermediate pipe parts arranged above and below the insertion pipe part. The insertion pipe part and the intermediate pipe part have an outer diameter smaller than the pipe inner diameter of the existing pipe, and the new insertion pipe part has a length that is less than the range that can be inserted so as to match the pipe axis direction of the existing pipe. How to update piping. The renewal method according to claim 1 , wherein the outer diameter of the new insertion pipe portion pushed into the buried portion of the existing pipe is the same as the outer diameter of the new intermediate pipe portion arranged above and below or behind the insertion pipe portion. . The renewal method according to claim 1 or 2 , wherein the new metal pipe to be pushed into the aging existing pipe is a stainless steel pipe.

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