| Product Name | Features | Applications |
| Aluminum wire O-ring | Aluminum wire O-rings with a purity of 99.99% and a diameter of less than 1mm need to be annealed at 350°C for 1 hour before use. Prior to usage, they should be cleaned with NaOH or dilute nitric acid. Due to the presence of an oxide film on the surface of the aluminum wire, welding can be challenging. To prevent aluminum oxidation, steel plating on the surface of the aluminum or the use of Al-Si alloy (with Si content ranging from 3% to 5%) can be employed. They can withstand temperatures of 400 to 500°C and are resistant to mercury corrosion. | Can be used in high-temperature or mercury diffusion pump systems. |
| Copper gasket and copper wire O-ring |
Copper gaskets and copper wire O-rings can withstand high-temperature baking up to 450°C. However, copper tends to develop a hard oxide layer during high-temperature baking. Plating the surface of the sealing ring with silver (with a silver layer thickness not exceeding 5μm) can prevent oxidation. Copper has higher hardness compared to aluminum and gold, requiring greater sealing force. Copper gasket material uses annealed cold-rolled copper sheets, namely soft copper sheets, with a Brinell hardness between 60 and 90. Silver solder or copper solder should be used for welding copper wire O-rings. |
Copper gaskets are generally used for flanges with nominal diameters less than 200mm, while copper wire O-rings can be used for flanges with nominal diameters greater than 250mm. |
| Gold wire O-ring | The material is 99.7% pure gold. Gold’s advantages include excellent chemical stability, corrosion resistance, non-oxidation when exposed to air for long periods, softness making it easy to process, good ductility, reusability, and minimal wear and tear. Commonly used gold wire diameters range from 0.5 to 2mm. A compression ratio of around 50% is typically employed, and the bolt diameter and number can be determined based on a compression force of 200 x 10^5 Pa. | Gold wire seals are primarily used for flange connections with nominal diameters greater than 250mm. |
| Indium O-ring | Indium wire O-ring or indium gaskets require relatively low sealing force and can operate at low temperatures. O-rings do not need to be pre-made; the fine wire ends can be overlapped and cold-welded during installation. If a ring shape is needed, the ends can also be cut at right angles and welded using solder in a weak flame from a torch. The main drawback of indium sealing is its poor heat resistance, with a maximum operating temperature not exceeding 150°C. | For applications where the temperature does not exceed 150°C. |
