Stainless steel manhole covers are not prone to rust. Rust removal for stainless steel manhole covers mainly involves two methods: shot blasting and jet blasting. Shot blasting utilizes the high-speed rotation of the impeller in a shot blasting machine to disperse abrasive particles towards the surface of the stainless steel manhole cover. The abrasive particles fly out at high speed, impacting and rubbing the surface of the stainless steel manhole cover, thereby removing rust and oxide scale.
Gun blasting uses compressed air that has undergone oil-water separation treatment to propel abrasive particles from a nozzle at high speed. The compressed air pressure is typically 0.4-0.6 MPa. The high-speed, pressurized abrasive particles, upon contact with the stainless steel manhole cover, generate friction and impact to remove oxide scale and rust.
Generally, both shot blasting and jet blasting methods are effective for removing rust from stainless steel manhole covers. However, these methods are not universally applicable. When a good method becomes available, it should be adopted. This requires gradual accumulation of experience through practical use.
