Vacuum Centering & O-ring (SUS304, VITON)

Model: PVF-03

PVF-03 is a centering-ring and O-ring set used when fastening KF (NW) and ISO standard vacuum flanges. The combination of a SUS304 centering ring and a VITON (FKM) O-ring is used to maintain airtightness at vacuum flange connections in semiconductor, display, solar, and laboratory applications.

Features

• Supports KF flange (KF16 - KF50) and MF flange (ISO63 - ISO320) standards
• Centering ring: SUS304 material, precision machined
• O-ring: VITON (FKM) material, chemical and heat resistant
• For maintaining tightness in semiconductor, display, and solar vacuum lines

Specifications

Frequently Asked Questions

Must the centering ring and O-ring be used as a set?

Yes. In KF and ISO flange systems, the centering ring locates and constrains the deformation of the O-ring, so it is standard to use them as a set. If only the O-ring is used without the centering ring, the O-ring may be displaced from the flange contact face, causing leakage. During assembly, always use the centering ring together.

What is the application range of VITON O-rings?

VITON (FKM) can be used in the range of approximately -20 to 200°C and offers good chemical resistance to general acids/alkalis, hydrocarbon-based fluids, and most process gases. Some corrosive gases used in deposition and etching processes (fluorine- or chlorine-based, etc.) may exceed VITON's capability, so higher-grade materials such as Kalrez (FFKM) should be reviewed for those environments.

How often should O-rings be replaced?

O-ring replacement cycles vary depending on operating temperature, process gas, and flange disassembly frequency. In general, it is safer to replace with new ones each time the flange is disassembled. Even for flanges fixed in place for long periods, O-rings should be replaced immediately if elasticity loss, discoloration, or cracks are confirmed during regular inspection.

How do I select the size?

Specifications are dedicated by KF (NW) or ISO flange standard and size (NW10/16/25/40/50, NW63/100/160/200, etc.). Tell us the flange size and standard in use and we will supply matching specifications.