What safety precautions should be taken during the polishing process of stainless steel seamless

What safety precautions should be taken during the polishing process of stainless steel seamless pipes? 

When processing stainless steel seamless pipes for polishing, the following safety precautions should be observed, covering aspects such as equipment operation, protective measures, and environmental management:

1. Equipment safety operation

Pre-start inspection: Ensure that the torque of the fixing bolts for the polishing wheel is ≥ 30N・m, the strength of the protective cover is sufficient to withstand 80m/s projectiles, and the response time of the emergency stop button is ≤ 0.5 seconds.

Speed limit: The linear speed of the grinding wheel ≤ 35m/s, the rotational speed of the abrasive belt machine ≤ 1800rpm. The automatic shutdown device must be sensitive when it exceeds the limit.

Power-off maintenance: When replacing grinding media or conducting maintenance, cut off the main power supply and hang a "Do Not Close Switch" sign. The discharge time of the capacitor should be ≥ 5 minutes.

2. Personnel protection requirements

Eye protection - Impact-resistant goggles (ANSI Z87.1 certified), a transparent protective screen (thickness ≥ 6mm acrylic) should be added in the polishing area.

Respiratory protection - For dry polishing, wear an N95 mask (filtration efficiency ≥ 95%), use a full-face respirator when the dust concentration is > 10mg/m³.

Hand protection - Cut-resistant gloves (EN 388 Level 5), add nitrile rubber gloves when in contact with corrosive polishing solutions (resistant to pH 1-14).

Body protection - Fly-splash apron (PVC coating), wear anti-shock safety shoes (impact resistance ≥ 15kN) for the feet. 

III. Hazardous Operations Control

Flammable and Explosive Environments:

When the polishing solution contains alcohol (concentration > 10%), open flames are prohibited in the workshop, and the static grounding resistance should be ≤ 100Ω.

When the dust concentration exceeds the explosion lower limit (aluminum powder <37g/m³), the explosion-proof dust removal system (wind speed ≥ 10m/s) must be activated.

Chemical Injury Prevention:

When in contact with nitrate-based polishing solution (concentration > 20%), a 2% sodium bicarbonate rinse solution must be provided. If splashed into the eyes, immediately rinse for 15 minutes and seek medical attention.

During electrolytic polishing, the grounding voltage of the tank ≤ 36V, and when the anode current density > 20A/dm², forced cooling (water temperature ≤ 35℃) is required. 

IV. Emergency and Environmental Management

Fire Extinguishing: When the polishing wheel catches fire due to friction, use ABC type dry powder fire extinguisher (with a range of ≥ 3m). Water is prohibited for extinguishing oil-based polishing liquid fires.

Waste Liquid Treatment: Polishing waste liquid containing heavy metals (Cr⁶+ > 0.5mg/L) must undergo neutralization and precipitation (with pH adjusted to 8-9) before being discharged.

Noise Control: Polishing machines must be equipped with sound insulation covers (with noise reduction of ≥ 25dB). When operators continuously work for more than 8 hours, the noise exposure limit should be ≤ 85dB (A).

V. Special Operating Conditions Notes

Inner Hole Polishing: When using magnetic grinding, the grinding needle diameter should be <0.8mm, and the magnetic field strength should be ≤ 1200Gs to prevent steel pipes from being adsorbed and deformed.

Thin-Walled Tube Processing: When the wall thickness is <1.5mm, the polishing pressure should be ≤ 0.15MPa to avoid finger injuries or workpiece splashing (a protective net should be added when the kinetic energy is > 10J). 

Strictly implementing the above measures can reduce the incidence of safety accidents by more than 80%, meeting the requirements of the ISO 45001 occupational health and safety management system.