Steel Pipe Shot Blasting Machine engineered to remove rust scale and mill scale

The steel pipe internal shot blasting machine is a dedicated surface treatment unit for cleaning, derusting and strengthening steel pipe inner walls. Different from conventional external shot blasters, it adopts a targeted blasting structure to convey steel shot, steel grit and other abrasives to pipe interiors. It effectively addresses the difficulties in treating inner cavities of long, large-diameter and thick-walled steel pipes, and serves as key equipment for oil & gas pipelines, water supply & drainage pipelines and structural steel pipe production.

Typical models & Specification

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 blasting lance is positioned along the central axis of the steel pipe, fitted with multiple directional nozzles at regular intervals. As the lance rotates and moves back and forth axially, high-speed abrasives spray from the nozzles to fully cover the entire inner wall, including hard-to-access pipe ends and weld seams.
• Adaptability to different pipe specifications: We can customize the blast lance length and nozzle quantity to match steel pipes with lengths of 3m to 20m and diameters of 50mm to 2000mm. Compact lances fitted with fine nozzles are adopted for small-diameter pipes, while heavy-duty lances with high-flow nozzles are used for large-diameter pipes to guarantee consistent blasting strength.
• Adjustable movement speed:The lance’s axial travel speed and rotational speed can be regulated separately. We slow down both speeds to prolong blasting time for pipes with heavy internal rust. For workpieces with light oxide scale in mass production, higher speeds are set to boost overall productivity..

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: Blasting intensity can be precisely regulated by tuning the pressure and material flow of the abrasive delivery system. Low blasting intensity is applied to thin-walled steel pipes to prevent wall abrasion. For thick-walled pipes such as high-pressure oil pipelines, high intensity is used to remove tough scale and reinforce inner surfaces.
• Treatment of special pipe types: The machine processes not only straight steel pipes, but also slightly bent pipes and pipe sections with welds. Thanks to the flexibly connected blast lance, it can accommodate small-angle bends and deliver effective cleaning to inner walls of curved segments.

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 may pre-set parameters including lance travel speed, rotation speed, abrasive flow rate and clamping force for various pipe sizes and save the settings in the system. For repeated production of the same pipe type, one-touch operation is available to maintain consistent processing quality.
• Real-time monitoring and fault alarm: The system enables real-time monitoring of the blast lance, abrasive recycling unit and dust collector. It will trigger an automatic shutdown and sound an alarm once faults including lance jamming, abrasive clogging or dust collector overload are detected, minimizing equipment damage and cutting maintenance hours.
• 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.