The steel pipe internal side shot blasting machine is a specialized surface treatment device designed exclusively for cleaning, derusting, and strengthening the inner walls of steel pipes. Unlike general shot blasting equipment that focuses on external surfaces, this machine uses a targeted shot blasting mechanism to deliver abrasive media (steel shots, steel grit, etc.) to the inner wall of steel pipes, solving the problem of difficult surface treatment for the internal cavity of long, large-diameter, or thick-walled steel pipes. It is a core piece of equipment in industries such as oil and gas pipelines, water supply and drainage pipelines, and structural steel pipe manufacturing.

The machine is equipped with a specialized internal shot blasting system, which is the core of its ability to treat steel pipe inner walls, with the following characteristics:

• Central blast lance design: A long blast lance runs through the axis of the steel pipe, with multiple directional nozzles evenly distributed on the lance. When the lance rotates and moves axially, the high-speed abrasive media ejected from the nozzles can cover the entire inner wall surface of the steel pipe, including the ends and weld joints that are hard to reach.
• Adaptability to different pipe specifications: The length of the blast lance and the number of nozzles can be customized according to the length (ranging from 3m to 20m) and diameter (from 50mm to 2000mm) of the steel pipe. For small-diameter pipes, a compact lance with fine nozzles is used; for large-diameter pipes, a reinforced lance with high-flow nozzles ensures uniform shot blasting intensity.
• Adjustable movement speed: The axial movement speed of the blast lance and the rotation speed can be adjusted independently. For pipes with severe inner wall rust, the speed is reduced to extend the shot blasting time; for batch pipes with light oxide scales, the speed is increased to improve production efficiency.

Aimed at the common contaminants on steel pipe inner walls (rust, oxide scale, welding slag, oil residues, and cementitious deposits), the machine has the following cleaning capabilities:

• Compliance with strict cleaning standards: It can achieve Sa2.5–Sa3 level surface cleaning (international standard for steel surface treatment). After treatment, the inner wall of the steel pipe is free of visible rust, oxide scale, and other contaminants, with a uniform rough surface, which provides an ideal base for subsequent processes such as anti-corrosion coating, cement lining, or plastic coating.
• Adjustable shot blasting intensity: By controlling the pressure of the abrasive delivery system and the flow rate of the media, the shot blasting intensity can be precisely adjusted. For thin-walled steel pipes, low intensity is used to avoid wall thinning; for thick-walled pipes used in high-pressure scenarios (e.g., oil pipelines), high intensity is adopted to remove stubborn scale and strengthen the inner wall.
• Treatment of special pipe types: It can handle not only straight steel pipes but also slightly bent pipes and pipes with welded joints. The flexible connection design of the blast lance can adapt to small-angle bends, ensuring that the inner wall of the bent section is also effectively cleaned.

The machine is equipped with a closed-loop internal abrasive recycling system, which solves the problem of abrasive collection in the narrow space of the steel pipe inner wall:

• Negative pressure collection + mechanical conveying: After shot blasting, the mixture of abrasive media, dust, and debris is collected at the pipe ends through a negative pressure suction device, and then transported to the separator through a screw conveyor. The separator uses air classification and screening technology to separate reusable abrasive media (separation accuracy > 90%) from waste debris and dust.
• Low-dust operation: The supporting high-efficiency dust collector (cartridge filter or bag filter) can capture more than 99.5% of the dust generated during the shot blasting process. The dust emission concentration is less than 20mg/m³, which meets the strict environmental protection requirements of pipeline manufacturing workshops and avoids dust pollution to the operating environment.
• Abrasive loss reduction: The closed-loop recycling system reduces the loss of abrasive media by more than 60% compared with open shot blasting methods, significantly reducing production costs for large-scale pipe processing.

To match the internal shot blasting process, the machine is configured with a specialized steel pipe clamping and conveying system:

• Dual-roller or three-roller positioning: The steel pipe is stably clamped by multiple groups of driving rollers, which drive the pipe to rotate slowly during the shot blasting process. This cooperation with the moving blast lance ensures that every part of the inner wall is evenly impacted by the abrasive media.
• Adjustable clamping force: The clamping force can be adjusted according to the pipe diameter and wall thickness to avoid deformation of thin-walled pipes during clamping and ensure stable rotation of heavy thick-walled pipes.
• Integration with production lines: It can be seamlessly connected to the steel pipe welding line, coating line, and cutting line, realizing automated loading, positioning, shot blasting, unloading, and transfer, and reducing manual intervention.

Modern steel pipe internal side shot blasting machines are equipped with an intelligent control system with the following capabilities:

• Parameter preset and storage: Operators can preset parameters such as lance movement speed, rotation speed, abrasive flow rate, and clamping force for different pipe specifications, and store them in the system. When processing the same type of pipe again, one-click operation can be realized, ensuring consistent treatment quality.
• Real-time monitoring and fault alarm: The system monitors the operating status of the blast lance, abrasive recycling system, and dust collector in real time. If faults such as lance jamming, abrasive blockage, or dust collector overload occur, the system will automatically stop and send an alarm, reducing equipment damage and maintenance time.
• Safety interlock protection: The equipment is equipped with door interlock, pressure protection, and emergency stop devices. When the equipment door is opened during operation, the system will automatically shut down to ensure the safety of operators.