1、 Clean control during the production process
Environmental requirements: The cleanliness of the production workshop should be at least ISO level 7 (≥ 0.5 μ m particles ≤ 352000 particles/m ³); Temperature and humidity control: 22 ± 2 ℃/55 ± 5% (anti-static adsorption particles).
Surface treatment process: (electrolytic polishing) 316L material surface roughness Ra ≤ 0.8 μ m (eliminating micro pits and dirt accumulation); (Passivation treatment) nitric acid+hydrofluoric acid solution to remove free iron ions (to prevent subsequent oxidation pollution).
2、 Packaging and Storage Standards
Inner packaging: double-layer vacuum aluminum plated bag (anti-static)
Storage environment: Inert gas cabinet with relative humidity ≤ 40%
Access tool: specialized fluororubber gloves (powder free)
3、 Cleaning verification before installation
Solvent cleaning: Medical grade isopropanol ultrasonic cleaning (removal rate of particles larger than 5 μ m ≥ 99%), acetone is prohibited.
Cleanliness testing: (VDA19.1 standard) membrane weighing method for detecting impurities (0 tolerance for particles>200 μ m); (White glove test) Wipe the surface of the gasket without visible residue.
4、 Anti pollution measures during installation process
Flange pretreatment: Use non-woven fabric dipped in ethanol to wipe the groove in one direction (do not rub back and forth).
Installation action specification: After the oval gasket is inserted into the groove, it is forbidden to rotate (to avoid metal scratching and debris generation); Bolt diagonal pre tightening (torque deviation ≤ 5%) to prevent gasket displacement.
Oval gaskets cannot be directly touched with bare hands, as sweat and salt can cause stress corrosion cracking! Microscopic cracks after compression deformation are prone to accumulate dirt and grime, therefore they cannot be reused. It is also prohibited to blow dry gas, as high-speed airflow can cause secondary pollution of metal particles.