OVERVIEW :: MODEL 23 :: MODEL 23 DS :: MODEL 23 A :: MODEL 23 XL :: MODEL 45 :: MODEL 45 A ::MODEL 45 XL :: MODEL 59 :: DIMENSIONAL CHART :: MAINTENANCE & INSTALLATION
SAF Viewports units are for use in low-pressure applications (5 PSI) where 100% shutoff is not required. Rectangular View Ports are available in three different sizes and a variety of styles.
Rectangular View Ports enable the operator to safely and clearly inspect the interior. Adjustments can be made under actual operating conditions without combustion or air infiltration. Two types of glass are available for a variety of viewing conditions. High and Low-temperature glass, as explained below, is protected by the stainless steel screen and stainless shutter. The viewing is done by pulling the handle down; when finished, release the handle and the shutter closes automatically. Glass can be cleaned and removed quickly by using wing nuts.
Each unit includes a 1/4″ NPT purge hole for adding cooling capabilities with air or nitrogen. Sealant can be added to improve the seal in low-pressure applications. All Rectangular View Ports are provided with a mounting flange gasket that fits securely between the unit and the vessel wall. All configurations of the Rectangular View Ports units are available in cast iron and stainless steel (except for the Model 23 A and 45 A, which is carbon steel) from stock. Fabrication in other metals for specific applications is available upon request.
All models are made of cast iron except Model 16 (Angular), which is carbon steel. Some units are also produced in stainless steel. Both the shutter and protective screen are stainless steel. Additional information can be found on the individual models below.
Standard vs. Extra Seal
Rectangular View Ports come in two models: Standard or Extra Seal. A mounting flange gasket is provided for installation between the unit and the furnace wall. The unit is equipped with a 1/4″ NPT purge hole to run air or nitrogen for cooling of the port. It can be replaced with a 1/2″ NPT hole.
The Extra Seal Rectangular View Port, designated by a “ES” in the model number, has been sealed with a high-temperature sealant between the components of the body and frame to prevent air leakage when used in a low-pressure application. A mounting flange gasket is provided for installation between the unit and the furnace wall. The unit is equipped with a 1/4″ NPT purge hole to run air or nitrogen for cooling of the port. If 1/4″ NPT hole is not sufficient, it can be replaced with a 1/2″ NPT hole.
Available Glass Types
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)*.
Borosilicate Clear – (also known as Pyrex) Designated by a “B” 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.
*Note: The iron or steel bodies have different maximum temperatures than the viewing glass.