Installation of Water Supply Steel Pipes with Large Diameters (Part One)
Abstract: This article mainly focuses on the research on the installation and construction technology of large-diameter water supply steel pipes, combined with the current installation and construction of large-diameter water supply steel pipes. First, the installation and construction technology of large-diameter water supply steel pipes is analyzed. Second, the key points for improving the installation and construction of large-diameter water supply steel pipes are discussed based on in-depth explanation and discussion of hoisting, riveting, welding, repair welding, defect treatment and anticorrosive coatings of steel pipes to strengthen the standardization and feasibility of the installation and construction of large-diameter water supply steel pipes and enhance the overall installation and construction level of steel pipes, aiming to provide a reference for related research.
Large-diameter water supply steel pipes have better water supply performance, so this type of water supply steel pipe has gradually been used in the construction of water supply projects, especially the installation and welding of large-diameter water supply steel pipes in recent years. Constructors have to face difficult construction and its installation effectiveness is directly related to the effectiveness of the safe operation of the water supply project. Therefore, during the installation and construction of large-diameter water supply steel pipes, it is necessary to determine the key points of the installation to better deal with the quality defects of water supply steel pipes.
1. Overview
(1) Riveting of steel pipes
The characteristic of the steel pipe's riveting is to realize the butt joint between two large-diameter steel pipes, and then perform welding of steel pipes. However, for water supply steel pipes with long lengths and diameters, if the steel pipe joints are welded in all directions, the corresponding construction is difficult. In the actual riveted steel pipe project, the accuracy of the joints of the butt steel pipe ends should be ensured, and the error of the riveted steel pipe should be limited at the same time. In the past riveting, the constructor would choose the supporting means to connect the steel pipes, and then perform electric welding. In fact, the above riveting and welding cannot accurately improve the accuracy of steel pipe butt joints, and there is even the possibility of affecting the contact points of steel bars. Aiming at compensating for the lack of riveting. A special riveting device can be selected to conduct the construction of large-diameter steel pipes. The new butt joint device is regarded as the foundation. The new butt joint device is regarded as the foundation. The support device of the rotating steel pipe can promote riveting based on this, and it is convenient for the turntable to play the supporting role of the steel pipe's support and bearing.
Large-diameter water supply steel pipes have better water supply performance, so this type of water supply steel pipe has gradually been used in the construction of water supply projects, especially the installation and welding of large-diameter water supply steel pipes in recent years. Constructors have to face difficult construction and its installation effectiveness is directly related to the effectiveness of the safe operation of the water supply project. Therefore, during the installation and construction of large-diameter water supply steel pipes, it is necessary to determine the key points of the installation to better deal with the quality defects of water supply steel pipes.
1. Overview
(1) Riveting of steel pipes
The characteristic of the steel pipe's riveting is to realize the butt joint between two large-diameter steel pipes, and then perform welding of steel pipes. However, for water supply steel pipes with long lengths and diameters, if the steel pipe joints are welded in all directions, the corresponding construction is difficult. In the actual riveted steel pipe project, the accuracy of the joints of the butt steel pipe ends should be ensured, and the error of the riveted steel pipe should be limited at the same time. In the past riveting, the constructor would choose the supporting means to connect the steel pipes, and then perform electric welding. In fact, the above riveting and welding cannot accurately improve the accuracy of steel pipe butt joints, and there is even the possibility of affecting the contact points of steel bars. Aiming at compensating for the lack of riveting. A special riveting device can be selected to conduct the construction of large-diameter steel pipes. The new butt joint device is regarded as the foundation. The new butt joint device is regarded as the foundation. The support device of the rotating steel pipe can promote riveting based on this, and it is convenient for the turntable to play the supporting role of the steel pipe's support and bearing.
(2) Welding of steel pipes
The steel pipe welding serves as a key point for the installation and construction of the steel pipe. The welding method of the gas shielded welding can be selected at this stage based on the perspective of pipe welding. Specifically, the welding process of the large diameter steel pipe material is carried out by the gas shielded welding, and the carbon dioxide auxiliary welding is selected. Regarding it as a prerequisite, a fusion effect can be generated between the weldment and the welding wire, and the penetration of the weldment can be enhanced by the arc action. Under the protection of carbon dioxide, the welding seam has high-quality characteristics. For welding equipment, this type of equipment involves the wire feeder, welding gun, DC power supply, etc., so it helps to recycle and deal with waste construction materials.
2. Key points for improving the installation and construction of large-diameter water supply steel pipes
(1) Hoisting of steel pipes
In the process of hoisting large-diameter steel pipes, a crawler crane should be selected, and the construction specification should be less than or equal to 40 tons. However, in some cases, the crawler crane is likely to be unstable due to the influence of the road conditions on the construction site. If you want to avoid the occurrence of the above situation, you can choose the construction road with good smoothness. Aiming at the hosting which needs to pass a special location near the foundation pit, the key point should be to compact the ground where the crane is located. At the same time, the car body rotation and the crane boom must be dealt with in time to ensure that the hoisting effect is sufficiently significant.
(2) Riveting and welding
In the process of riveting the steel pipe, the elastic layer on the surface of the steel pipe should be laid. The polyethylene closed-cell foam board of the layer is selected and the thickness is set to be 10 mm. In the construction process, first, apply a low-density polyvinyl chloride primer with a width greater than or equal to 10 mm, and then wrap the foam board. A rotating butt joint device of steel pipes with a high safety index should be chosen for riveting steel pipes, forming by two dependent turntables and successively distributing around the bottom side of the steel pipe. The turntable contains brackets, one end of which is connected with the bearing. During the trial period, the two turntables are docked to complete the butt installation of the two pins. In order to ensure that the plane position and elevation of steel pipes are valid, several points must be controlled:
① The parallelism error of straight pipes of steel pipes and expansion joints and axis design does not exceed 0.2%.
② The deviation of the installation core of the steel pipe does not exceed 5 mm.
③ The vertical value of both ends of steel pipes shall not exceed 3 mm.
2. Key points for improving the installation and construction of large-diameter water supply steel pipes
(1) Hoisting of steel pipes
In the process of hoisting large-diameter steel pipes, a crawler crane should be selected, and the construction specification should be less than or equal to 40 tons. However, in some cases, the crawler crane is likely to be unstable due to the influence of the road conditions on the construction site. If you want to avoid the occurrence of the above situation, you can choose the construction road with good smoothness. Aiming at the hosting which needs to pass a special location near the foundation pit, the key point should be to compact the ground where the crane is located. At the same time, the car body rotation and the crane boom must be dealt with in time to ensure that the hoisting effect is sufficiently significant.
(2) Riveting and welding
In the process of riveting the steel pipe, the elastic layer on the surface of the steel pipe should be laid. The polyethylene closed-cell foam board of the layer is selected and the thickness is set to be 10 mm. In the construction process, first, apply a low-density polyvinyl chloride primer with a width greater than or equal to 10 mm, and then wrap the foam board. A rotating butt joint device of steel pipes with a high safety index should be chosen for riveting steel pipes, forming by two dependent turntables and successively distributing around the bottom side of the steel pipe. The turntable contains brackets, one end of which is connected with the bearing. During the trial period, the two turntables are docked to complete the butt installation of the two pins. In order to ensure that the plane position and elevation of steel pipes are valid, several points must be controlled:
① The parallelism error of straight pipes of steel pipes and expansion joints and axis design does not exceed 0.2%.
② The deviation of the installation core of the steel pipe does not exceed 5 mm.
③ The vertical value of both ends of steel pipes shall not exceed 3 mm.
