Crude oil tank cleaning robots and dredging robots serve distinct industrial purposes but share some robotic principles like autonomy and remote operation. Tank cleaning robots are specialized for hazardous, confined oil storage environments, focusing on sludge removal and safety in explosive atmospheres. Dredging robots, in contrast, are engineered for underwater or sediment-heavy aquatic settings, emphasizing sediment excavation in open, fluid-filled spaces. Below, I outline the key design differences across core aspects, based on industry-standard systems 

AspectCrude Oil Tank Cleaning robotDredging Robot
Industry StandardATEX ZONE 0/1Non Exproof/CNEX
Primary MediumAir/Sludge confined hazardousWater/sediment open submerged
Walking SystemMagnet build in rubberRubber or chain cralwer
PowerDual motor 37kwOne motor 18.5kw 
Power back designNot with robot,outside tankCarried by robot back,enter tank
Size deploymentCompact can enter 19inch manholeLarger modular ,surface launched
Core toolsJets,shredder,slurry pump, vacuum suctionCutters,slurry pump



1. ATEX ZONE 0/1 VS None Ex-proof or normal Ex-proof working conditions 

 VS 

•  Crude Oil Tank Cleaning Robots: Designed for enclosed, confined spaces like 28m-diameter storage tanks with viscous, flammable sludge (e.g., 0.5m depth). Structures are compact (fitting 600mm manways) and corrosion-resistant (e.g., stainless steel alloys) to handle toxic vapors (H2S), hydrocarbons, and minimal water. They prioritize vertical/horizontal adhesion in low-gravity, non-submerged conditions.

•  Dredging Robots: Built for open-water bodies (rivers, reservoirs, lakes) or industrial water tanks, submerged up to 100-300m depths. Designs feature buoyant, waterproof hulls (e.g., modular fiberglass or steel frames) resistant to water pressure, currents, and abrasive sediments. They include flotation aids for surface deployment.

•  Key Difference: Tank robots emphasize explosion containment and confined-space maneuverability; dredging robots focus on hydrodynamic stability and depth tolerance.

2.Walking mechanism 

 VS  

•  Crude Oil Tank Cleaning Robots: Designed for oily sludge slippery working conditions,special designed rubber built in strong Magnet 

•  Dredging Robots: Rubber or chain cralwer without strong magnet ,can not adhere to tank bottom and walk properly 

•  Key Difference: Tank cleaning robots emphasize on walking on oily slippery steel plate with magnet attached to the bottom 

3.Motor system 

 VS  

•  Crude Oil Tank Cleaning Robots: Designed for working while walking ,dual motors more powerful

•  Dredging Robots: One motor for both walking and suction,very weak

•  Key Difference: Tank cleaning robots more powerful when working while walking .

4.Power pack system 

   vs  

•  Crude Oil Tank Cleaning Robots: Designed for less weight and compact  ,power pack system with power station ,not goes into tank ,robot can work more flexible and less maintainance

•  Dredging Robots: Old design ,carry power pack on back,very heavy and bulk,can not pass through 20inch manhole, more difficult to do maintainance 

•  Key Difference: Tank cleaning robots less weight,compact can pass through 19inch man hole more user friendly.

5.Pumping system 

VS 

•  Crude Oil Tank Cleaning Robots: Two pump ,one slurry pump for liquid phase sludge ,vacuum solids pump with air tank,Ex aircompressor  for hard sludge transfer

•  Dredging Robots: Only one slurry pump,not suitable for hard sludge transfer 

•  Key Difference: Tank cleaning robots built for tank bottom hard sludge cleaning purpose

6.Robot head 

 VS 

•  Crude Oil Tank Cleaning Robots:designed for not only mixing  and suction ,but also grinding ,cuttings and vacuum suction 

•  Dredging Robots: Only for liquid phase ,solids phase not effective

•  Key Difference: Tank cleaning robots built for tank bottom hard sludge cleaning purpose