2 Problems and optimization methods in the cutting process

2.1 Problems in the cutting process

During the whole cutting process, all parties strictly follow the cutting procedures of pipe beveling machinery, but the phenomenon of a jamming knife or even broken knife still occurs. Divers need to remove the old blade and install a new blade. It is difficult to remove the blade afterwards. The removal work takes about an hour, which seriously affects the construction progress and operation efficiency of the project. After the replacement of the new blade, the sea pipe cutting operation is repeated, and the knife jam phenomenon will occur repeatedly after reaching a certain cutting depth.

2.2 Analysis of the cause of stuck knife

A simple analysis of the cause of the jam knife phenomenon, the sea pipe at the working place is in a suspended state, the sea pipe is subject to gravity, during the cutting process, the sea pipe will bend, the cutting point will fall, and the upper end of the sea pipe will be compressed Force, the lower end is stretched and expanded. With the deepening of the cutting depth of the submarine tube, the wall thickness of the submarine tube becomes thinner. Due to its own gravity, the submarine tube has a slight deformation and falling trend, the upper level is squeezed, the angle becomes smaller, and the lower level has an expansion angle The trend of becoming larger. As the pipe wall becomes thinner, the deformation of the bending of the sea pipe will increase, and the squeezing force on the upper level will increase. With the deepening of the cutting depth, the contact surface between the diamond cutting blade and the groove increases, the squeezing force received by the blade increases, f friction force = F squeezing force μ friction coefficient, the friction coefficient does not change, with the extrusion The force becomes larger and the friction becomes larger. When the cutting depth is larger, the jam knife appears, and the jam knife appears near the upper level where the squeezing force is relatively large.

2.3 Cutting optimization method

In order to complete the cutting operation of the submarine pipe better, faster and more efficiently, the conventional cutting operation steps are optimized, and the following two methods are adopted: first, widening the cutting groove: second, adding a floating bag to offset the gravity of the submarine pipe. When the width of the groove is greater than

When the deformation of the submarine tube is not reached, one side of the blade does not come into contact with the submarine tube, the squeezing force received by the blade is negligible, and the phenomenon of jamming will not occur.

When the cutting depth of the sea pipe reaches 5em, exit the blade, move the beveling machine 3cm and reposition it. After the installation is completed, start the hydraulic equipment to widen the bevel. Avoid shift cutting

Card knife. This kind of operation is equivalent to multiple cuts by a cutting port, and it needs to be repeatedly installed in place of the beveling machine, which requires more construction time. In order to improve construction efficiency, the second optimization method is adopted: the floating bag offsets the gravity of the submarine pipe itself.

A floating bag is installed on both sides of the submarine pipe cutting port. After a certain amount of inflation, the submarine pipe cutting operation is started. When a knife or a machine is blocked at the upper level, more gas is flushed into the floating bag Until the jamming phenomenon disappears and the machine runs normally. This optimization method reduces the number of times the beveling machine is reinstalled and improves construction efficiency. The floating bag counteracts the gravity of the submarine tube. After the submarine tube is cut, there will be no obvious phenomena such as the submarine tube falling. The subdivision of the submarine tube cutting groove is smooth and regular, and there is no tearing or burr. Blue welding.

3 Conclusion

Pipe beveling machine is used in the actual construction of submarine oil and gas pipeline cutting. By optimizing construction schemes such as widening the bevel and floating bag to offset the gravity of the submarine pipeline, the cutting operation of submarine oil and gas pipeline is promoted safely and efficiently. The optimization of the beveling machine's submarine pipeline cutting plan has achieved the actual effect of reducing costs and increasing efficiency.

Pipe Beveling Machine