The cleanliness control of elliptical gaskets includes the production process, packaging and storage, as well as pre-installation and installation process.
1. Cleanliness control during production
- Environmental requirements: The cleanliness of the production workshop shall be ≥ ISO Class 7 (≥0.5μm particles ≤ 352,000 per m³); Temperature and humidity control: 22±2℃/55±5% (to prevent static adsorption of particles).
- Surface treatment process: (Electrolytic polishing) The surface roughness Ra of 316L material shall be ≤0.8μm (to eliminate micro-pits that hide dirt); (Passivation treatment) Nitric acid + hydrofluoric acid solution is used to remove free iron ions (to prevent subsequent oxidation pollution).
2. Packaging and storage specifications
- Inner packaging: Double-layer vacuum aluminized bags (anti-static).
- Storage environment: Inert gas cabinet with relative humidity ≤40%.
- Tools for taking: Special fluororubber gloves (powder-free).
3. Cleanliness verification before installation
- Solvent cleaning: Medical-grade isopropanol ultrasonic cleaning (removal rate of particles above 5μm ≥99%), acetone is prohibited.
- Cleanliness testing: (VDA19.1 standard) Filter membrane weighing method to detect impurities (zero tolerance for particles ＞200μm); (White glove test) No visible residues on the surface of the gasket after wiping.
4. Anti-pollution measures during installation
- Flange pre-treatment: Wipe the groove in one direction with non-woven fabric dipped in ethanol (back-and-forth friction is prohibited).
- Installation operation specifications: The elliptical gasket is prohibited from rotating after being placed in the groove (to avoid metal scratches and debris); Bolts are pre-tightened diagonally (torque deviation ≤5%) to prevent gasket displacement.
- Elliptical gaskets must not be touched directly with bare hands. Sweat salt can cause stress corrosion cracking! Micro-cracks after compression deformation are easy to hide dirt, so they cannot be reused. In addition, purging with dry gas is prohibited, as high-speed airflow can cause secondary pollution of metal particles.
The above content and data are for industry popularization.
About Us
Wenzhou Huahai Sealing Co., Ltd., a veteran firm, focuses on R-type metal ring gaskets. It holds ISO9001, API-6A, API17D certifications, and special equipment licenses — proof of quality and standards.
Whether facing high temperature, pressure, or corrosion, we’ll match you with the right material.
The above content and data come from public online sources. Contact us if there are errors.