Sight Glass, 316L Stainless, C-Axis Sapphire Window

Sight window with NPT threads conforming to the ASME B1.20.1 Standard. This is a drip-in equivalent to a standard National Taper Pipe fitting. The sight glass features a sapphire window hermetically sealed into the housing with a Viton™ seal durometer 90. For visual inspection, machine vision, laser sensors, in use with all common hydraulic oils, refrigerants, pharmaceutical processing equipment. This sight glass is an ideal choice for applications requiring no compromises in optical clarity. The window is flat on both sides, and precisely polished to surface quality of 50-30 S-D per MIL-O-13830. The window material is C-Axis sapphire. This enables the sight glass to support applications requiring extended optical transmission into the UV and IR regions. Specifically, this window transmits in the range 175 nm - 4.5 µm wavelength. The window is sealed into the housing with a high durometer Viton seal. This sight glass has a long working life under severe temperature swings and prolonged exposures to UV light. In reverse pressure applications, (pressure outside the HEX, not from the inside of the fitting), pressure is rated to 150 bar (2175 psi) at maximum operating temperature. In deep vacuum applications, the sight glass is Helium leak-tight to 10xE-5 mbar·L/s. Vacuum inside the vessel, ambient pressure outside the HEX.