CN114636024A - High-strength steel cylinder steel-concrete composite pipe - Google Patents
High-strength steel cylinder steel-concrete composite pipe Download PDFInfo
- Publication number
- CN114636024A CN114636024A CN202210472545.7A CN202210472545A CN114636024A CN 114636024 A CN114636024 A CN 114636024A CN 202210472545 A CN202210472545 A CN 202210472545A CN 114636024 A CN114636024 A CN 114636024A
- Authority
- CN
- China
- Prior art keywords
- strength steel
- steel cylinder
- cylinder
- composite pipe
- socket ring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L9/00—Rigid pipes
- F16L9/08—Rigid pipes of concrete, cement, or asbestos cement, with or without reinforcement
- F16L9/085—Reinforced pipes
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L21/00—Joints with sleeve or socket
- F16L21/02—Joints with sleeve or socket with elastic sealing rings between pipe and sleeve or between pipe and socket, e.g. with rolling or other prefabricated profiled rings
- F16L21/022—Joints with sleeve or socket with elastic sealing rings between pipe and sleeve or between pipe and socket, e.g. with rolling or other prefabricated profiled rings used with sleeves or nipples for pipes of the same diameter, or with reduction pieces
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L58/00—Protection of pipes or pipe fittings against corrosion or incrustation
- F16L58/02—Protection of pipes or pipe fittings against corrosion or incrustation by means of internal or external coatings
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Rigid Pipes And Flexible Pipes (AREA)
Abstract
The invention discloses a high-strength steel cylinder and steel concrete composite pipe which comprises a high-strength steel cylinder, a concrete cylinder and an anticorrosive coating, wherein the high-strength steel cylinder is used for bearing the internal water pressure of a pipeline, the concrete cylinder is arranged on the inner side of the high-strength steel cylinder and is used for bearing the external pressure of the pipeline, the anticorrosive coating is arranged on the outer side of the high-strength steel cylinder, the concrete cylinder is arranged in a manner of being tightly attached to the inner wall of the high-strength steel cylinder, and the anticorrosive coating is arranged in a manner of being tightly attached to the outer wall of the high-strength steel cylinder. The invention has reasonable structural design, and the high-strength steel cylinder steel is formed by arranging the concrete cylinder at the inner side of the high-strength steel cylinder
The composite pipe can effectively improve the capability of bearing internal and external pressure of the water pipe, can ensure that the water pipe is not damaged by pressure under various pressure conditions, and meanwhile, the arrangement of the anticorrosive coating can prevent the high-strength steel cylinder from being corroded by the environment and the change thereofAnd further the service life of the water delivery pipeline can be effectively prolonged.
Description
Technical Field
The invention belongs to the technical field of water delivery or fluid delivery pressure pipelines, and particularly relates to a high-strength steel cylinder reinforced concrete composite pipe.
Background
Original steel
The composite pipeline is a steel cylinder concrete pipe (PCCP), the pressure water conveying pipeline is widely applied to water conveying and water transfer engineering, and the steel cylinder concrete pipe has obvious economic advantages compared with an all-metal pipe, so the composite pipeline is popular with users. However, the composite pipe also has the great defects that the structural defect is that the pipeline bears the reinforcing steel bars of internal pressure, the quality is unstable, the phenomenon of broken bars is easy to generate, and the whole section of pipeline (4-6 meters) has one broken bar, and all the reinforcing steel bars are lost. In addition, the outer protective layer of the pipeline is unreliable, so that the reinforcing steel bar is easy to corrode and break, and pipeline safety accidents are caused.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a high-strength steel cylinder reinforced concrete composite pipe aiming at the defects in the prior art, the structural design is reasonable, and the high-strength steel cylinder steel is formed by arranging a concrete cylinder on the inner side of the high-strength steel cylinder
The composite pipe can effectively improve the capability of bearing internal and external pressure of the water pipe, can ensure that the water pipe is not damaged by pressure under various pressure conditions, and meanwhile, the arrangement of the anticorrosive coating can avoid the high-strength steel cylinder from being corroded by the environment and the change thereof, thereby effectively prolonging the service life of the water pipe.
In order to solve the technical problems, the invention adopts the technical scheme that: the high-strength steel cylinder reinforced concrete composite pipe is characterized in that: the pipeline anti-corrosion device comprises a high-strength steel cylinder for bearing the internal water pressure of the pipeline, a concrete cylinder arranged on the inner side of the high-strength steel cylinder and used for bearing the external pressure of the pipeline, and an anti-corrosion layer arranged on the outer side of the high-strength steel cylinder;
the concrete cylinder is arranged to be attached to the inner wall of the high-strength steel cylinder, and the anticorrosive coating is arranged to be attached to the outer wall of the high-strength steel cylinder.
The high-strength steel cylinder reinforced concrete composite pipe is characterized in that: one end of the high-strength steel cylinder is provided with a socket ring, and the other end of the high-strength steel cylinder is provided with a socket ring matched with the socket ring.
The high-strength steel cylinder reinforced concrete composite pipe is characterized in that: the outer ring of the socket ring is provided with a plurality of annular seal grooves for installing seal rings.
The high-strength steel cylinder reinforced concrete composite pipe is characterized in that: the anticorrosive coating covers the socket ring and the outer side wall of the high-strength steel cylinder.
The high-strength steel cylinder reinforced concrete composite pipe is characterized in that: the socket ring comprises a socket section and a transition connecting section, and the outer side of the socket section and the outer side of the high-strength steel cylinder are both in smooth connection with the outer side of the transition connecting section.
The high-strength steel cylinder reinforced concrete composite pipe is characterized in that: the concrete cylinder covers the socket ring, the high-strength steel cylinder and the inner side wall of the transition connecting section.
The high-strength steel cylinder and steel concrete composite pipe is characterized in that the inner diameter of the socket ring and the inner diameter of the transition connecting section are equal to the inner diameter of the high-strength steel cylinder, and the outer side of the socket ring and the outer side of the anticorrosive coating are located on the same circumference.
The high-strength steel cylinder reinforced concrete composite pipe is characterized in that: the tensile strength of the high-strength steel cylinder is not less than 235 MPa.
Compared with the prior art, the invention has the following advantages:
1. the high-strength steel cylinder steel is formed by arranging the concrete cylinder on the inner side of the high-strength steel cylinder
The composite pipes are further connected to form a water delivery pipeline which is normalWhen the high-strength steel cylinder is in operation, water flows in the concrete cylinder to generate certain hydrodynamic pressure on the water delivery pipeline, when water does not flow, certain hydrostatic pressure is generated on the water delivery pipeline, and when a pipeline system is adjusted and closed, water hammer pressure with violent pressure alternately rising and falling can be generated; meanwhile, when the outside of the water pipe is subjected to pressure load, the concrete cylinder can bear the external pressure without being damaged, and the service life of the water pipe can be effectively prolonged.
2. According to the invention, the anticorrosive layer is arranged on the outer side of the high-strength steel cylinder, so that the high-strength steel cylinder can be protected, and the high-strength steel cylinder is prevented from being corroded by the environment and the change thereof, so that the high-strength steel cylinder is ensured
The composite pipe is safe to use for a long time.
In conclusion, the high-strength steel cylinder is reasonable in structural design, and the high-strength steel cylinder is formed by arranging the concrete cylinder on the inner side of the high-strength steel cylinder
The composite pipe can effectively improve the capability of bearing internal and external pressure of the water pipe, can ensure that the water pipe is not damaged by pressure under various pressure conditions, and meanwhile, the arrangement of the anticorrosive coating can avoid the high-strength steel cylinder from being corroded by the environment and the change thereof, thereby effectively prolonging the service life of the water pipe.
The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.
Drawings
FIG. 1 is a schematic structural diagram of the present invention.
FIG. 2 shows two high-strength steel cylinders according to the present invention
The connection structure of the composite pipe is shown schematically.
Description of reference numerals:
1-high-strength steel cylinder; 2-a concrete cylinder; 3-an anticorrosive coating;
4-a socket ring; 4-1-a socket section. 4-2-a transition junction;
5, a socket ring; 5-1-annular seal groove; 6-sealing ring.
Detailed Description
As shown in fig. 1 and 2, the high-strength steel cylinder comprises a high-strength steel cylinder 1 for bearing the internal water pressure of a pipeline, a concrete cylinder 2 arranged on the inner side of the high-strength steel cylinder 1 for bearing the external pressure of the pipeline, and an anticorrosive coating 3 arranged on the outer side of the high-strength steel cylinder 1;
the concrete cylinder 2 is arranged to be closely attached to the inner wall of the high-strength steel cylinder 1, and the anticorrosive coating 3 is arranged to be closely attached to the outer wall of the high-strength steel cylinder 1.
When in practical use, the high-strength steel cylinder is formed by arranging the concrete cylinder 2 at the inner side of the high-strength steel cylinder 1
The composite pipes are further connected to form a water delivery pipeline, when the water delivery pipeline normally runs, water flows in the concrete cylinder 2, certain hydrodynamic pressure is generated on the water delivery pipeline, when water does not flow, certain hydrostatic pressure is generated on the water delivery pipeline, and when a pipeline system is adjusted and closed, water hammer pressure with violent pressure alternately rising and falling can be generated, the design of the high-strength steel cylinder 1 can ensure that the water delivery pipeline is not damaged by pressure under various pressure conditions, and the problem of rib breakage in the traditional design can be thoroughly solved; meanwhile, when the outside of the water pipe is subjected to pressure load, the concrete cylinder 2 can bear the external pressure without being damaged, and the service life of the water pipe can be effectively prolonged.
It should be noted that, by arranging the anticorrosive coating 3 on the outer side of the high-strength steel cylinder 1, the high-strength steel cylinder 1 can be protected, and the high-strength steel cylinder 1 is prevented from being corroded by the environment and the change thereof, so as to ensure that the high-strength steel cylinder steel is protected
The composite pipe is safe to use for a long time.
During specific implementation, the concrete cylinder 2 is positioned in the high-strength steel cylinder 1 and is fixed with the high-strength steel cylinder 1, and the concrete cylinder 2 mainly bears the external pressure of the pipeline and is ensured not to be damaged or cracked and not to reduce the structural strength under the expected maximum external pressure; the concrete cylinder 2 should have good water tightness and no cracks which are not allowed by the process, and the anti-cracking and sealing performance of the concrete cylinder 2 can be enhanced by adding fibers and the like into the concrete during the molding of the concrete cylinder 2.
It should be noted that the anticorrosive coating 3 must have good sealing performance, water tightness, air impermeability, firmness and reliability, and will not be damaged by common collision, crack or corrosion performance reduction; the anti-corrosion layer 3 is designed and implemented according to the soil quality of the section where the pipeline is buried and the corrosion strength of the contained water, and preferably, the anti-corrosion layer 3 is epoxy resin type cement mortar.
When the internal pressure of the pipeline acts on the composite pipeline, when the concrete cylinder 2 and the high-strength steel cylinder 1 deform in the same way, the force borne by the high-strength steel cylinder 1 is 10 times that of the concrete cylinder 2, so that the high-strength steel cylinder 1 mainly bears the internal pressure of the pipeline; however, the high-strength steel cylinder 1 is easy to deform due to the thin wall, and the concrete cylinder 2 is large in thickness and good in pressure resistance, so that the high-strength steel cylinder mainly bears the external pressure of the pipeline.
In this embodiment, one end of the high-strength steel cylinder 1 is provided with a socket ring 4, and the other end of the high-strength steel cylinder 1 is provided with a socket ring 5 matched with the socket ring 4.
During practical use, the socket ring 4 and the socket ring 5 have enough strength, and are guaranteed not to be damaged or cracked under the action of corresponding pressure in the pipe, the high-strength steel cylinder 1 and the concrete cylinder 2 are both cylinders, the socket ring 4 and the socket ring 5 are both circular rings, and the socket ring 4 and the socket ring 5 are both integrally formed with the high-strength steel cylinder 1 or the socket ring 4 and the socket ring 5 are both welded and fixed with the high-strength steel cylinder 1.
In this embodiment, the outer ring of the socket ring 5 is provided with a plurality of annular seal grooves 5-1 for mounting the seal ring 6.
When in actual use, the sealing ring 6 is a rubber sealing ring, and after the upper sealing rubber ring is arranged in the annular sealing groove 5-1, the space between the socket ring 5 and the socket ring 4 can be sealed, so that the water leakage at the joint of the pipeline is ensured.
In this embodiment, the anticorrosive coating 3 covers the socket ring 4 and the outer side wall of the high-strength steel cylinder 1, one end surface of the anticorrosive coating 3 is flush with one end surface, far away from the high-strength steel cylinder 1, of the socket ring 4, and the other end surface of the anticorrosive coating 3 is closely attached to one end surface, close to the high-strength steel cylinder 1, of the socket ring 5.
When the water pipe is actually used, the anti-corrosion layer 3 extends to the outer side wall of the socket ring 4, so that the pipe connecting piece can be effectively protected from corrosion, and the service life of the whole water pipe is further ensured; the socket ring 5 is placed inside the socket ring 4 and can be protected by the socket ring 4.
It should be noted that the outer side of the socket ring 5 is not provided with the anticorrosive coating 3, so that the construction material can be effectively saved, and the connection reliability of the socket ring 5 and the socket ring 4 can be ensured.
In the embodiment, the bell mouth ring 4 comprises a bell mouth section 4-1 and a transition connecting section 4-2, and the outer side of the bell mouth section 4-1 and the outer side of the high-strength steel cylinder 1 are both smoothly connected with the outer side of the transition connecting section 4-2.
In practical use, the inner diameter of the socket section 4-1 is larger than the outer diameter of the high-strength steel cylinder 1, the cross section of the transition connecting section 4-2 is a circular ring, the inner diameter of the transition connecting section 4-2 is the same as the inner diameter of the high-strength steel cylinder 1, the outer diameter of the transition connecting section 4-2 is gradually reduced from the socket ring 4 to the direction of the high-strength steel cylinder 1, the maximum outer diameter of the transition connecting section 4-2 is equal to the outer diameter of the socket section 4-1, and the minimum outer diameter of the transition connecting section 4-2 is equal to the outer diameter of the high-strength steel cylinder 1.
It should be noted that the socket section 4-1 and the transition connecting section 4-2 are integrally formed, and the transition connecting section 4-2 is arranged to perform two high-strength steel cylinder steels
When the composite pipe is connected, the socket ring 5 can be limited, the sealing performance inside the pipeline can be effectively guaranteed, and the stress concentration phenomenon caused by the rapid change of the diameter outside the pipeline is reduced.
In this embodiment, the concrete cylinder 2 covers the inner side wall of the socket ring 5, the high-strength steel cylinder 1 and the transition connecting section 4-2, one end face of the concrete cylinder 2 is flush with one end face, far away from the high-strength steel cylinder 1, of the transition connecting section 4-2, and the other end face of the concrete cylinder 2 is flush with one end face, far away from the high-strength steel cylinder 1, of the socket ring 5.
During actual use, the concrete cylinder 2 extends into the socket ring 5 and the transition connecting section 4-2, and a plurality of high-strength steel cylinder steels can be ensured
The flatness of the inner ring of the pipeline formed after the composite pipe is connected.
In this embodiment, the inner diameter of the socket ring 5 and the inner diameter of the transition connecting section 4-2 are both equal to the inner diameter of the high-strength steel cylinder 1, and the outer side of the socket ring 5 and the outer side of the anticorrosive coating 3 are located on the same circumference.
In this embodiment, the tensile strength of the high-strength steel cylinder 1 is not less than 235 MPa.
In practical use, the high-strength steel cylinder 1 must have good tensile strength, and is not damaged under the action of water internal pressure of corresponding pressure grade, so that the bursting damage of the pipeline is not caused, and the strength of the high-strength steel cylinder is generally 2 times higher than that of the common steel pipe material.
When the invention is practically used, two high-strength steel cylinders are used
When the composite pipe is connected, firstly, a high-strength steel cylinder steel is used
Installing a sealing ring 6 on a socket ring 5 of the composite pipe, and then using the other high-strength steel cylinder steel
The socket ring 4 of the composite pipe is sleeved on the socket ring 5, so that a high-strength steel cylinder steel is formed
Socket ring 5 of composite pipe and another high-strength steel cylinder
The transition connecting section 4-2 of the bell ring 4 of the composite pipe is tightly attached.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, changes and equivalent structural changes made to the above embodiment according to the technical spirit of the present invention still fall within the protection scope of the technical solution of the present invention.
Claims (8)
1. The high-strength steel cylinder reinforced concrete composite pipe is characterized in that: the pipeline anti-corrosion device comprises a high-strength steel cylinder (1) for bearing the internal water pressure of the pipeline, a concrete cylinder (2) arranged on the inner side of the high-strength steel cylinder (1) and used for bearing the external pressure of the pipeline, and an anti-corrosion layer (3) arranged on the outer side of the high-strength steel cylinder (1);
the concrete cylinder (2) is closely attached to the inner wall of the high-strength steel cylinder (1) to be arranged, and the anticorrosive coating (3) is closely attached to the outer wall of the high-strength steel cylinder (1) to be arranged.
2. The high-strength steel cylinder reinforced concrete composite pipe according to claim 1, characterized in that: one end of the high-strength steel cylinder (1) is provided with a socket ring (4), and the other end of the high-strength steel cylinder (1) is provided with a socket ring (5) matched with the socket ring (4).
3. The high-strength steel cylinder reinforced concrete composite pipe according to claim 2, characterized in that: the outer ring of the socket ring (5) is provided with a plurality of annular seal grooves (5-1) for installing seal rings.
4. The high-strength steel cylinder reinforced concrete composite pipe according to claim 2, characterized in that: the anticorrosive layer (3) covers the socket ring (4) and the outer side wall of the high-strength steel cylinder (1).
5. The high-strength steel cylinder reinforced concrete composite pipe according to claim 2, characterized in that: the bell mouth ring (4) comprises a bell mouth section (4-1) and a transition connecting section (4-2), and the outer side of the bell mouth section (4-1) and the outer side of the high-strength steel cylinder (1) are both in smooth connection with the outer side of the transition connecting section (4-2).
6. The high-strength steel cylinder reinforced concrete composite pipe according to claim 5, characterized in that: the concrete cylinder (2) covers the inner side walls of the socket ring (5), the high-strength steel cylinder (1) and the transition connecting section (4-2).
7. The high-strength steel cylinder and steel concrete composite pipe as claimed in claim 5, wherein the inner diameter of the socket ring (5) and the inner diameter of the transition connecting section (4-2) are both equal to the inner diameter of the high-strength steel cylinder (1), and the outer side of the socket ring (5) and the outer side of the anticorrosive coating (3) are located on the same circumference.
8. The high-strength steel cylinder reinforced concrete composite pipe according to claim 1, characterized in that: the tensile strength of the high-strength steel cylinder (1) is not less than 235 MPa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210472545.7A CN114636024A (en) | 2022-04-29 | 2022-04-29 | High-strength steel cylinder steel-concrete composite pipe |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210472545.7A CN114636024A (en) | 2022-04-29 | 2022-04-29 | High-strength steel cylinder steel-concrete composite pipe |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114636024A true CN114636024A (en) | 2022-06-17 |
Family
ID=81952196
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210472545.7A Pending CN114636024A (en) | 2022-04-29 | 2022-04-29 | High-strength steel cylinder steel-concrete composite pipe |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114636024A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115041855A (en) * | 2022-06-30 | 2022-09-13 | 山河智能特种装备有限公司 | Welding structure and welding process for ultrahigh-strength steel and high-strength steel |
-
2022
- 2022-04-29 CN CN202210472545.7A patent/CN114636024A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115041855A (en) * | 2022-06-30 | 2022-09-13 | 山河智能特种装备有限公司 | Welding structure and welding process for ultrahigh-strength steel and high-strength steel |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN201462207U (en) | Sealing device between protective well through hole and underground pipeline | |
| CN101619779B (en) | Sealing device for buried pipe connected with protective well | |
| CN114636024A (en) | High-strength steel cylinder steel-concrete composite pipe | |
| CN217208136U (en) | High-strength steel cylinder steel-concrete composite pipe | |
| CN105605351A (en) | Large-caliber T-shaped-port block-cast nodular cast iron pipe fitting | |
| CN203641701U (en) | Lightweight concrete protective wall combined water charging and discharging pipeline | |
| CN110159843B (en) | Steel cylinder type concrete pressure pipe and water supply pipeline | |
| CN210135349U (en) | Flange sealing device | |
| CN207392370U (en) | A kind of civic building draining is managed with PE | |
| CN108253205B (en) | Pipeline and assembly thereof | |
| CN211175717U (en) | High-toughness pipe | |
| CN109268624B (en) | Life-prolonging pipeline structure and preparation method thereof | |
| CN201259025Y (en) | Sealing device for buried pipe protection well | |
| CN215948411U (en) | Outer interface shutoff forming device is contained to steel circular pipe | |
| CN210128135U (en) | Water supply pipe | |
| CN216009819U (en) | Combined joint reinforced concrete drain pipe | |
| CN221504348U (en) | Pressure pipeline | |
| CN116146802B (en) | Prestressed steel cylinder concrete pipe connecting structure and installation method | |
| CN216640799U (en) | Sewage tunnel section of jurisdiction structure | |
| CN221683850U (en) | Large-caliber fiber reinforced steel cylinder concrete composite pipe | |
| CN214838994U (en) | Wear-resistant epoxy glass flake paint anti-corrosion prestressed steel cylinder concrete pipe for conveying seawater | |
| CN211175850U (en) | Large-caliber ultrahigh-pressure movable elbow | |
| CN220416480U (en) | Prestressed steel cylinder concrete pipe with hot galvanizing prestressed steel wire | |
| CN217519410U (en) | Pipeline installation connecting device | |
| CN101311601B (en) | Steel cylinder strengthened steel faucet longitudinal reinforced concrete ceiling pipe |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |