• FOR LOW PRESSURE APPLICATION ONLY! (5 PSI or LESS)  
• Fruehauf Viewports Threaded Gate View Port are available in cast iron, stainless steel and carbon steel upon request.
• The stainless steel slide arrangement in the blast gate gives added protection and life to the lens during operation, and allows maintenance to be performed with added safety during vessel down-time.
• Add a purge connection for additional cooling. Positioned on either the glass or vessel side of the blast gate housing, standard purge is at 3 o’clock position. Alternative placement of the purge is available upon request.
• Thread sizes range from 2 inch to 6 inch NPT threaded openings. 
• Standard glass options include clear borosilicate (Pyrex) or clear quartz.
• Custom lenses available upon request.

Quartz Clear - Designated by a "Q" in the model number. Maximum intermittent operating temperature is 2048°F. Maximum continuous operating temperature is 1600°F (Glass Only)*.
Pyrex Clear - (borosilicate glass) Designated by a "P" in the model number. Maximum intermittent operating temperature is 554°F. Maximum continuous operating temperature is 446°F (Glass Only)* . Glass is heat strengthened for safety and is coated with a heat reflecting shield.