1. Assumes use of Standard (i.e. not tapped) mounting flange.

Viewports will give a long and reliable service if they are properly treated. They must be stored carefully & kept free from damage. During bakeout they must have their temperature accurately controlled. We recommend that you cover the external surface of the viewport with aluminium foil, which will reduce temperature variations across the surface of the glass. For each viewport there is a maximum recommended temperature ramp rate (refer to the appropriate product table) which is the maximum rate at which the temperature can either rise or fall during bakeout . It is equally important to consider the viewports when the system has stopped baking. Opening the bakeout ovens with the system still hot can cause unacceptable cooling temperature rates.

Always use an annealed gasket when mounting a viewport as it reduces the mechanical stresses seen by the glass. Tighten the mounting bolts equally over several passes. Use a torque wrench to ensure equal sealing torques.

Never use a viewport that appears to be, or is known to be damaged. A replacement viewport costs far less than repairing a system that has been the subject of an implosion caused by a faulty viewport.