JP2023051229A - Pipe member - Google Patents

Abstract

To provide a pipe member excellent in fire resistance, capable of securing strength even through containing expansive graphite, and easy to construct.SOLUTION: A pipe member (100) has: a straight pipe (1) having an intermediate layer containing thermally expandable graphite, an outer layer made of a vinyl chloride resin covering the outside of the intermediate layer, and an inner layer made of a vinyl chloride resin covering the inside of the intermediate layer; a socket part (2) formed by enlarging one end part of the straight pipe (1); a rubber ring arrangement part (4) provided on an inner peripheral surface of the socket part (2); and a rubber ring (3) arranged in the rubber ring arrangement part (4). An inner diameter of the socket part (2) is 117% or more and 145% or less of an inner diameter of the straight pipe (1). The intermediate layer contains 1 pt.mass or more and 20 pts.mass or less of the thermally expandable graphite with respect to 100 pts.mass of the vinyl chloride resin.SELECTED DRAWING: Figure 1A

Description

The present invention relates to piping members.

Plumbing pipes for drainage or water supply are arranged in section penetrations inside buildings such as collective housing. In order to prevent flames, heat and smoke from rising from the floor where the fire is occurring to the upper floor through the section penetration, normally in the case of a fire, a flame shield is installed at the section penetration in plumbing pipes, Fireproof measures are taken to block heat and smoke. As a fireproof measure for piping, for example, a method is known in which thermally expandable graphite is added to a piping pipe that is inserted into a section penetrating portion.
For example, Patent Literature 1 proposes a straight piping material having a refractory expansion layer containing a specific amount of thermally expandable graphite and coating layers covering the inside and outside of the refractory expansion layer. The invention of Patent Literature 1 discloses that the refractory expandable layer expands during combustion to block the inside of the pipe and prevent fire and smoke from reaching the compartment penetration.
Moreover, polyvinyl chloride resin is generally used as a piping pipe for drainage or water supply. There is a standing pipe with a socket, in which the end of a piping pipe is diameter-expanded and a rubber ring is placed inside the diameter-expanded portion. A piping system is constructed by inserting another piping pipe into the enlarged diameter portion of the standpipe with socket and connecting the piping pipes together. Patent Document 2 discloses a joint containing a resin composition containing a polyvinyl chloride resin and expandable graphite.

Japanese Patent No. 4960806 Japanese Patent Application Laid-Open No. 2020-38005

When connecting a pipe such as that disclosed in Patent Document 1 to another pipe, a joint is required to connect the pipes. In the standpipe with socket disclosed in Patent Document 2, it is necessary to expand the diameter of the end of the standpipe in order to dispose the rubber ring. However, since the joint of Patent Document 2 contains expansive graphite, it is likely to crack when forcedly deformed, and the strength may decrease when the diameter is expanded for a standpipe with a socket. If the outer diameter of the standpipe containing expandable graphite becomes too large, the strength of the standpipe will be reduced, and there is a risk that the expanded portion will break.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a piping member that is excellent in fire resistance, can ensure strength while containing expansive graphite, and is easy to construct. and

The present invention has the following aspects.
(1) A piping member according to an embodiment of the present invention is
A straight pipe having an intermediate layer containing thermally expandable graphite, an outer layer made of vinyl chloride resin covering the outside of the intermediate layer, and an inner layer made of vinyl chloride resin covering the inside of the intermediate layer. ,
a socket part formed by enlarging one end of the straight pipe;
a rubber ring arrangement portion provided on the inner peripheral surface of the socket;
a rubber ring arranged in the rubber ring arrangement portion;
has
The inner diameter of the socket is 117% or more and 145% or less of the inner diameter of the straight pipe,
The intermediate layer contains 1 part by mass or more and 15 parts by mass or less of the thermally expandable graphite with respect to 100 parts by mass of the vinyl chloride resin.
(2) In the piping member described in (1) above, the rubber ring placement portion has an outer diameter equal to or larger than the outer diameter of the socket, and the inner peripheral surface of the socket has a It may have an extending concave widened portion.

ADVANTAGE OF THE INVENTION According to this invention, the piping member which is excellent in fire resistance, can ensure intensity|strength, although it contains expansive graphite, and is easy to construct can be provided.

It is a sectional view of a piping member concerning a 1st embodiment of the present invention. FIG. 1B is a cross-sectional view conceptualizing the II-II cross section of FIG. 1A. FIG. 5 is a cross-sectional view of a piping member according to a second embodiment of the present invention; It is a sectional view of piping structure concerning a 3rd embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram which shows an example of the manufacturing apparatus which manufactures the piping member which concerns on one Embodiment of this invention.

Preferred embodiments of the present invention will be described in detail below with reference to the drawings. In the present specification and drawings, constituent elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description.
The present invention is not limited to the configurations disclosed in the embodiments, and various modifications are possible without departing from the scope of the present invention. In addition, the lower limit value and the upper limit value are included in the numerical limit range described below.

(First embodiment)
A pipe (piping member) according to a first embodiment of the present invention will be described.
FIG. 1A is a cross-sectional view of tube 100 according to the present embodiment. As shown in FIG. 1A, the longitudinal direction of the tube 100 is the Z direction, the lateral direction of the paper of FIG. 1 is the X direction, and the direction perpendicular to both the Z direction and the X direction (the depth direction of the paper of FIG. 1) is the Y direction. . In the Z direction of FIG. 1, the side on which the socket portion 2, which will be described later, is arranged is the upper side.

The pipe 100 includes a straight pipe 1, a socket portion 2 formed by enlarging one end of the straight pipe 1, a rubber ring arrangement portion 4 provided on the inner peripheral surface of the socket portion 2, and the rubber and a rubber ring 3 arranged in the ring arrangement portion.
The straight pipe 1 is formed in a cylindrical shape having the same diameter. The straight pipe 1 is used, for example, as a vertical pipe for piping and water supply pipes. The length L (mm) of the straight pipe 1 is, for example, 2600 mm or more and 4000 mm or less. Table 1 shows the thickness (thickness) t1 of the straight pipe 1 for each specific nominal diameter.

The socket portion 2 is formed by enlarging one end of the straight pipe 1 . The straight pipe 1 and the socket portion 2 are connected by a tapered pipe portion 7 . The outer diameter D3 of the socket portion 2 is larger than the outer diameter D4 of the straight pipe 1 . The outer diameter D3 of the socket portion 2 of this embodiment is constant. The other pipe end of the straight pipe 1 is pushed into a socket 2 of another pipe 100 for connection.

A rubber ring arrangement portion 4 in which a rubber ring (O-ring) 3 is arranged is provided on the inner peripheral surface of the socket portion 2 . By arranging the rubber ring 3 in the rubber ring arranging part 4, the water cut-off property can be improved. The rubber ring 3 is sandwiched between the rubber ring arrangement portion 4 and the pipe end portion at the lower end of the straight pipe 1 of another pipe 100 . As a result, the rubber ring 3 exhibits water stopping properties.

As shown in FIG. 1B, the straight pipe 1 and the pipe 100 include an intermediate layer 51 containing thermally expandable graphite, an outer layer 50 made of vinyl chloride resin covering the outer side of the intermediate layer 51, and the intermediate layer 51 and an inner layer 52 made of a vinyl chloride resin covering the inside of the.
The intermediate layer 51 contains refractory thermally expandable graphite. As an example of the thermally expandable graphite used in the present embodiment, powders such as natural flake graphite, pyrolytic graphite, and Kish graphite are acid-treated with an inorganic acid and a strong oxidizing agent to insert an inorganic acid between graphite layers, A crystalline compound obtained by adjusting the pH can be used.
Concentrated sulfuric acid, nitric acid, selenic acid and the like can be used as the inorganic acid. Concentrated nitric acid, perchloric acid, perchlorates, permanganates, bichromates, hydrogen peroxide and the like can be used as strong oxidizing agents.

The thickness of the intermediate layer 51 is preferably 52% or more and 87% or less, more preferably 62% or more and 72% or less of the total thickness. As a result, the thermally expandable graphite that thermally expands during combustion can be sufficiently contained, and the strength of the tube 100 can be ensured.

The intermediate layer 51 may contain stabilizers, inorganic fillers, flame retardants, lubricants, processing aids, impact modifiers, heat resistance improvers, antioxidants, Additives such as light stabilizers, ultraviolet absorbers, pigments, plasticizers and thermoplastic elastomers may be added.

The outer layer 50 and the inner layer 52 are made of vinyl chloride resin. Examples of vinyl chloride-based resins that can be used include rigid polyvinyl chloride resins, impact-resistant rigid polyvinyl chloride resins, and heat-resistant rigid polyvinyl chloride resins.

The total thickness of the outer layer 50 and the inner layer 52 is preferably 13% or more and 48% or less of the total thickness. If the total thickness of the outer layer 50 and the inner layer 52 is less than 13%, the mechanical strength may deteriorate. If the combined thickness of the outer layer 50 and the inner layer 52 exceeds 48%, the fire resistance may deteriorate. More preferably, the total thickness of the outer layer 50 and the inner layer 52 is 28% or more and 38% or less.

Thermally expandable graphite has the property of expanding when heated. Since the tube 100 has an intermediate layer 51 containing thermally expandable graphite, the intermediate layer 51 expands in the event of a fire to block flame and smoke within the compartment penetration.

The inner diameter D1 (mm) of the socket portion 2 is 117% or more and 145% or less of the inner diameter D2 (mm) of the straight pipe 1 . That is, the diameter expansion ratio (D1/D2) of the socket portion 2 with respect to the straight pipe 1 is 117% or more and 145% or less. D1 (mm) is the inner diameter D1 (mm) of the socket portion 2 and does not include the thickness of the rubber ring 3, as shown in FIG. 1A.
Since the intermediate layer 51 contains thermally expandable graphite, the strength may decrease when the diameter is expanded. Damage such as cracks does not occur, and strength can be ensured.
In addition, by setting the diameter expansion ratio to 117% or more, a water stop member such as a rubber ring, packing, or O-ring is provided in the socket part 2 to improve water stoppage, and the pipe can be easily inserted into the socket part 2. can do.
The diameter expansion ratio (D1/D2) of the socket portion 2 with respect to the straight pipe 1 is preferably 120% or more and 135% or less. In particular, pipes 100 with a nominal diameter of 125 mm or more (outer diameter of 140 mm or more and inner diameter of 125 mm or more) have a high outer diameter-to-wall thickness ratio (SDR) and are susceptible to cracking during socket processing, so this range is preferred. In addition, it is possible to employ a water stop member having a lip portion that facilitates the insertion of a pipe into the socket 2 and has a high level of water stoppage. can.

Since the tube 100 according to this embodiment contains thermally expandable graphite in the intermediate layer 51, it has excellent fire resistance. Further, by controlling the diameter expansion rate of the socket portion 2 with respect to the straight pipe 1, it is possible to ensure strength while containing expandable graphite. Furthermore, since it has the socket portion 2, it can be connected to another pipe without using a joint or the like, so construction is easy.
The pipe 100 according to the present embodiment can be used even when it has a large diameter, for example, when the outer diameter D4 of the straight pipe 1 exceeds 200 mm.

The intermediate layer 51 contains 1 part by mass or more and 20 parts by mass or less of thermally expandable graphite with respect to 100 parts by mass of the vinyl chloride resin. As a result, sufficient thermal expansibility can be obtained during combustion, resulting in excellent fire resistance. The intermediate layer 51 preferably contains 3 parts by mass or more and 15 parts by mass or less of thermally expandable graphite with respect to 100 parts by mass of the vinyl chloride resin. , containing thermally expandable graphite in a proportion of 4 parts by mass or more and 10 parts by mass or less.

(Second embodiment)
The second embodiment of the present invention will be described below, but the differences from the first embodiment will be mainly described, and the rest will be the same as the first embodiment, so redundant description will be omitted.
FIG. 2 is a cross-sectional view of a pipe (piping member) 100B according to a second embodiment of the invention. The pipe 100B of this embodiment differs mainly in the shape of the socket 2 of the first embodiment. That is, the socket portion 2B according to the present embodiment has the enlarged diameter portion 5B. Specifically, as shown in FIG. 2, the rubber ring placement portion 4B has an outer diameter DB5 that is equal to or greater than the outer diameter D3 of the socket portion 2B, and the inner peripheral surface of the socket portion 2B has a circumferential It has a concave enlarged diameter portion 5B extending in the R direction.
The enlarged diameter portion 5B has a convex shape toward the outside of the socket portion 2B. That is, in the arrow view of FIG. 2, the enlarged diameter portion 5B is a groove projecting in the X direction. The rubber ring 3B is fitted into this enlarged diameter portion 5B.

The diameter of the socket portion 2B of the present embodiment is increased, but the diameter expansion is smaller than that of the socket portion 2 of the first embodiment. That is, compared with the tapered tube portion 7 of the first embodiment, the diameter expansion of the tapered tube portion 7B of the present embodiment is gentle. This is because the enlarged diameter portion 5B to which the rubber ring 3B is fitted has an outward convex shape, so that the inner diameter DB1 of the socket portion 2B can be secured even if the diameter of the tapered tube portion 7B is gradually enlarged. .
As a result, the pipe 100B according to the present embodiment can further reduce damage such as cracks due to diameter expansion. Therefore, the tube 100B can ensure more strength.
The inner diameter DB1 (mm) of the socket portion 2B is preferably 117% or more and 145% or less of the inner diameter D2 (mm) of the straight pipe 1 . That is, the diameter expansion ratio (DB1/D2) of the socket portion 2B with respect to the straight pipe 1 is preferably 17% or more and 45% or less. The diameter expansion ratio (DB1/D2) of the socket portion 2B with respect to the straight pipe 1 is preferably 25% or more and 42% or less. DB1 (mm) is the inner diameter DB1 (mm) of the socket portion 2B, as shown in FIG. 2, and does not include the thickness of the rubber ring 3B.

(Third embodiment)
The third embodiment of the present invention will be described below, but mainly the differences from the first and second embodiments will be described, and the rest is the same as the first and second embodiments. Therefore, redundant description is omitted.
FIG. 3 is a cross-sectional view of a joint (piping member) 100C according to this embodiment. As shown in FIG. 3, the joint 100C has a straight pipe 1C that is shorter than the pipes 100 and 100B. Joint 100C functions as an expansion joint, for example. For example, in the joint 100C, the straight pipe 1C has a length LC (mm) of 430 mm or more and 600 mm or less. Moreover, it is good also as a composite member which connected the socket 9 like FIG.
The joint 100C according to this embodiment can obtain the same effects as the pipes 100 and 100B of the above embodiments. That is, since the joint 100C contains thermally expandable graphite in the intermediate layer 51, it is excellent in fire resistance. Further, by controlling the diameter expansion rate of the socket portion 2C with respect to the straight pipe 1C, it is possible to ensure strength while containing expandable graphite.

(Example)
Hereinafter, the technical content of the present invention will be further described with reference to examples of the present invention. The conditions in the examples shown below are examples of conditions adopted for confirming the feasibility and effect of the present invention, and the present invention is not limited to these example conditions. Moreover, the present invention can adopt various conditions without departing from the gist of the present invention and as long as the objects of the present invention are achieved.

Crack evaluation of sockets was examined for straight pipes (piping members) having an outer diameter of 89 mm to 216 mm.
(Raw materials used for fittings)
Thermally expandable graphite: MZ-260 manufactured by Air Water Inc., expansion start temperature of 260° C. or higher, average aspect ratio of 25.3.
· Polyvinyl chloride resin: TH1000 manufactured by Taiyo Vinyl Co., Ltd.
- Polyethylene resin: Suntec B770 manufactured by Asahi Kasei Corporation.
· Lead-based stabilizer: SL-1000 manufactured by Sakai Chemical Co., Ltd.
• Polyethylene-based lubricant: Hi-Wax 4202E manufactured by Mitsui Chemicals, Inc.
- Flame retardant (aluminum hydroxide): H-31 manufactured by Showa Denko K.K., average particle size 18 µm.

(Regarding processing method from straight pipe to straight pipe with socket)
In the heat processing step, the pipe to be processed is subjected to heat processing. Specifically, the portion to be processed of the pipe to be processed is heated and softened to deform the portion to be processed.

In the socket processing, the diameter of the end of the tube to be processed is expanded to form the socket. The resulting fitting thus has a receptacle. As the heating process, both the bending process and the socket process may be applied to the pipe to be processed. In this case, the resulting tubing has a socket.

As a method for heating the portion to be processed, a method of irradiating the portion to be processed with infrared rays from an infrared heater is preferable from the viewpoint of productivity. The output of the infrared heater can be, for example, in the range of 250 to 1000W. Examples of the shape of the infrared heater include a rod shape and a plate shape. The distance between the part to be processed and the infrared heater can be adjusted, for example, within the range of 5 cm to 50 cm. When irradiating the infrared rays, the pipe to be processed and the infrared heater may be relatively rotated in order to uniformly heat the portion to be processed. In this case, only the tube to be processed may be rotated, only the infrared heater may be rotated, or both of them may be rotated. The rotation speed can be appropriately adjusted according to the output of the infrared heater and the distance between the workpiece and the infrared heater. However, the heating method is not limited to the above method, and other heating methods may be employed. For example, the end of the tube to be processed may be immersed in a heated oil bath for a predetermined time.
The heating time during heat processing is preferably set so that the surface temperature after heating is 120 to 180°C, more preferably 130 to 160°C. If the surface temperature after heating is equal to or higher than the above lower limit, the temperature of the pipe to be processed becomes sufficiently high even when the refractory layer contains a large amount of thermally expandable graphite, and the pipe to be processed can be satisfactorily heated and processed. It is hard to crack during processing. If the surface temperature after heating is equal to or lower than the above upper limit, even if thermally expandable graphite with a low expansion start temperature is used for the refractory layer, it is possible to perform socket processing without expansion due to overheating during processing. .
After the end of the pipe to be processed is heated by a predetermined method, a diameter expansion die is inserted into the end of the heated pipe to expand the diameter of the end of the non-processed pipe to form a socket. do.

(Method for producing three-layer tube containing thermally expandable graphite)
The pipe material consisted of an outer layer, an intermediate layer which is a fireproof layer, and an inner layer.
A resin composition constituting the intermediate layer was obtained as follows.
Polyvinyl chloride resin (Taiyo Vinyl Co., Ltd., TH1000) 100 parts by mass, thermally expandable graphite (Air Water Co., Ltd., MZ-260, expansion start temperature 260 ° C. or higher, average aspect ratio 25.3) The number of parts described in Table 2, 2 parts by mass of a lead-based stabilizer (SL-1000, manufactured by Sakai Chemical Co., Ltd.), 0.5 parts by mass of a polyethylene-based lubricant (Hi-Wax 4202E, manufactured by Mitsui Chemicals, Inc.), After blending 3 parts by mass of aluminum hydroxide (manufactured by Showa Denko K.K., H-3), using a Henschel mixer with an internal volume of 200 liters (manufactured by Kawada Kogyo Co., Ltd.), the resin composition (B -1) was obtained.
Resin compositions constituting the outer layer and the inner layer were obtained as follows.
Polyvinyl chloride resin (TH1000 manufactured by Taiyo Vinyl Co., Ltd.) 100 parts by mass, tin-based stabilizer (manufactured by Daikyo Kasei Kogyo Co., Ltd., trade name "STX-80") 2 parts by mass, polyethylene lubricant (manufactured by Mitsui Chemicals, Inc. , Hiwax 4202E) and 3 parts by mass of calcium carbonate (manufactured by Shiraishi Calcium Co., Ltd., Whiten SB) were blended, and then stirred and mixed with a Henschel mixer having an internal volume of 200 liters (manufactured by Kawada Kogyo Co., Ltd.). to obtain a resin composition (B-2).
Using the manufacturing apparatus shown in FIG. 4, the resin composition (B-2) is supplied to the hopper 66 of the first extruder 61, and the resin composition (B- 1) was supplied. The resin temperatures in the first extruder 68 and the second extruder 69 were set to 180° C., and each resin was supplied from the first extruder 68 and the second extruder 69 to the mold 70 . The molding temperature in the mold 70 is set to 190 ° C., extruded into a tubular shape, cooled and cut into a predetermined length, and the outer diameter is 119 mm, the inner diameter is 111 mm, and the resin composition (B-2) has a thickness. A tube to be processed comprising an outer layer and an inner layer each having a thickness of 1.5 mm, and an intermediate layer having a thickness of 3.0 mm formed between the outer layer and the inner layer and formed of the resin composition (B-1) made.
Thereafter, a processing step was performed to expand the diameter of the end portion of the pipe to be processed at a predetermined diameter expansion rate, thereby manufacturing a joint having a fire-resistant layer.

Table 2 shows the socket crack evaluation for each joint.
The item "thermally expandable graphite (parts by mass)" in Table 2 indicates the ratio of the thermally expandable graphite by mass to 100 parts by mass of the vinyl chloride resin in the intermediate layer. The item "pipe inner diameter" in Table 2 indicates the inner diameter D2 (mm) of the straight pipe 1 in FIGS. 1A and 2 . The "maximum expanded diameter portion inner diameter" in Table 2 indicates the inner diameter D1 (mm) of the socket portion 2 in the case of FIG. 1A, and the inner diameter DB1 (mm) of the socket portion 2B in the case of FIG. "Maximum diameter expansion ratio" in Table 2 indicates "D1/D2" in the case of FIG. 1A and "DB1/D2" in the case of FIG. "Rubber ring diameter" in Table 2 indicates the thickness (mm) of the rubber ring. In Table 2, "O" in "Evaluation of socket cracks" indicates that cracks did not occur in the socket, and "X" indicates that cracks occurred in the socket.

As shown in Table 2, in Examples 1 to 7 in which the inner diameter of the socket was 117% or more and 145% or less of the inner diameter of the straight pipe, cracks did not occur in the socket. On the other hand, in Comparative Example 1, in which the inner diameter of the socket was 153% of the inner diameter of the straight pipe, cracks occurred in the socket.
Also, in Comparative Example 2 in which the amount of "thermally expandable graphite (parts by mass)" was 21 parts by mass, cracks occurred in the socket.
From the above, it was found that by applying the present invention, it is possible to obtain a pipe that can secure strength while containing expandable graphite and that is easy to construct.

Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person having ordinary knowledge in the technical field to which the present invention belongs can conceive of various modifications or modifications within the scope of the technical idea described in the claims. It is understood that these also belong to the technical scope of the present invention. For example, a rubber ring stopper portion that prevents the rubber ring from coming off may be provided at the tip of the socket.

1 Straight pipes 2, 2B, 2C Socket portions 3, 3B, 3C Rubber rings 4, 4B, 4C Rubber ring arrangement portions 5B, 5C Expanded diameter portions 7, 7B, 7C Tapered pipe portion 50 Outer layer 51 Intermediate layer 52 Inner layer 100, 100B Piping member (pipe)
100C joint

Claims (2)

A straight pipe having an intermediate layer containing thermally expandable graphite, an outer layer made of vinyl chloride resin covering the outside of the intermediate layer, and an inner layer made of vinyl chloride resin covering the inside of the intermediate layer. ,
a socket part formed by enlarging one end of the straight pipe;
a rubber ring arrangement portion provided on the inner peripheral surface of the socket;
a rubber ring arranged in the rubber ring arrangement portion;
has
The inner diameter of the socket is 117% or more and 145% or less of the inner diameter of the straight pipe,
A piping member in which the intermediate layer contains the thermally expandable graphite in a proportion of 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the vinyl chloride resin. 2. The rubber ring arrangement portion according to claim 1, wherein the rubber ring placement portion has an outer diameter equal to or larger than the outer diameter of the socket portion, and has a concave enlarged diameter portion extending in the circumferential direction on the inner peripheral surface of the socket portion. piping material.

Images