KF sight glass

Core Material: Most use borosilicate glass for its low thermal expansion and chemical resistance. For extreme durability, sapphire glass offers scratch resistance and high IR transmission.

• Performance Limits: High-vacuum rating down to 10⁻⁸ Torr. Max bakeout temp is usually 150°C (with sapphire models handling up to 350°C). Pressure max is roughly 4 bar (58 psi).
• Installation: Uses a KF quick-flange system: an elastomer O-ring (FKM/Viton) with a centering ring, secured by a hinged clamp.

 Flange Material & Sizes: Typically AISI 304 stainless steel or aluminum 6082. Standard KF sizes range from DN16 to DN50, with view diameters varying accordingly (e.g., 16mm for KF16 up to 52mm for KF50).

Specialized variants also exist: removable viewports let you swap glass without breaking the main flange seal, and hygienic fused models use glass-to-metal fusion with no epoxy or crevices to prevent bacteria trapping.