Vacuum Viewports and Access Doors Information

Vacuum viewports and access doors are components for viewing, accessing or transferring samples or process devices in a vacuum chamber or system. Viewports and doors are available with glass, quartz, sapphire or other specialty window materials.  Different window materials are used depending on the wavelength to be transmitted through the window to a detector.   Access doors or access caps may or may not have a window.  Vacuum component types, flange system or fitting port type, flange size specifications, and ratings and features are important parameters to consider when searching for vacuum viewports and access doors.

Choices for Vacuum Component Types

Choices for vacuum component type include access cap or port cover, door, shutter or shield, and viewport.  Caps or covers are vacuum component that seal a port or distribution pipe of a vacuum chamber. Vacuum doors provide a means to access a vacuum chamber or system for material throughput, transferring samples or process devices or maintenance. Shutters or shield protect a window from evaporated or sputtered coating material that would otherwise collect on the window of a viewport or door. Viewports are components for viewing or optically sensing samples or process devices in a vacuum chamber or system.  Window materials for vacuum viewports and access doors include optical grade glass, quartz, and sapphire. 


Flange or seal types for vacuum viewports and access doors include none, metal seal, elastomeric seal or o-rings, ISO-BF, ISO-CF, ISO-KF or ISO-QF, ISO-LF, ISO-MF, ANSI ASA, Conflat, Del-Seal, Pyraflat, and Tri-Seal.  Choices for fitting connectors or port types include flange, weld or braze stub, threaded, and compression fitting.  Flange size specifications include ISO nominal flange size, viewing diameter, flange outer diameter, length or thickness, and flange bore or inner diameter. ISO nominal flange size refers to the nominal bore size.  Choices range from NW 10 to NW 1000.  Common ratings and features include vacuum or pressure range, operating or bake-out temperature, and features.  Common specifications for vacuum valves include port size or outer diameter, vacuum or pressure range, and operating or bake-out temperature.  The vacuum or pressure range can be rough or low (< 760, > 1 torr), medium (< 1, >10-3 torr), high vacuum (< 10-3, >10-8 torr), ultra-high vacuum (< 10-8 torr), and elevated pressures (> 760 torr). The maximum operating or bake-out temperature that the fitting, flange or vacuum component can be exposed to is important to consider.  Features of vacuum viewports can include integral windows, low profile, non-magnetic, square or custom shape, and zero profile.