Tank Sight Glass type 118 | Noris

Tank Sight Glass Noris Type 118

The Noris Type 118 is a circular low-pressure sight glass designed for visual inspection and illumination of the interior of closed vessels, such as tanks, boilers, and silos. The assembly is intended for direct welding to the vessel shell and consists of a base, flange-type cover, glass disc, gaskets, and bolts.

Operating Conditions

• Nominal pressure: PN 2.5 / up to 2.5 bar
• Operating temperature: 150 °C or 280 °C, depending on sealing version and glass type
• Sizes: DN 50 to DN 200
• Reference standard: DIN 28120
• Material certificate: EN 10204-3.1 optional

Materials and Sealing

Available base and cover materials: RSt 37-2, H II, 1.4541, 1.4571. Bolts: galvanized 5.6, A2-70, or A4-70. Glass: borosilicate per DIN 7080 or soda-lime per DIN 8902. Standard sealing is asbestos-free, with alternative materials or O-ring available for vacuum service.

Typical Applications

• Low-pressure liquid storage tanks
• Boilers and process vessels requiring visual inspection
• Silos or closed vessels where internal inspection is necessary
• Locations requiring local verification of level, color, foaming, or medium clarity

Version Selection

For corrosive or demanding media, stainless steel grades 1.4541 or 1.4571 are recommended. For increased mechanical protection, a double safety window (Bauform 126) can be specified. For tanks with glass fouling, a wiper (Bauform 190) is available. No actuator is required, as this is a static visual inspection component.

FAQ

Is it suitable for mains pressure?
No. It is intended for low-pressure applications up to 2.5 bar.

Can it be used under vacuum?
Yes, with the appropriate O-ring sealing version.

What is checked during maintenance?
Bolt torque, gasket condition, glass for cracks or clouding, and signs of leakage at the sealing seat.