Tank Sight Glass type 220 | Noris

Tank Sight Glass Noris Type 220

The Noris Bauform 220 is a rectangular sight glass designed for direct welding onto tanks, vessels, and silos. It is intended for local visual observation of liquid surfaces and is not a continuous level measurement device.

Operating Conditions

• Nominal pressure: 16 bar / PN 16
• Temperature: up to 243 °C, suitable for saturated steam or hot water in direct contact
• Glass: borosilicate reflex, DIN 7081
• Sealing: asbestos-free as standard; other materials available on request
• Available body lengths: 170 to 930 mm
• Visible length: 120 to 880 mm

Construction Materials

Standard combinations include weld base in WN 1.4571 or RSt 37-2, cover in WN 1.4571 or RSt 37-2, and bolts in A4-70 or zinc-plated 8.8. Product documentation also lists 1.0038 and 1.4571 as material options.

Sizing and Installation

Lengths 500–740 mm use two glass discs; 930 mm uses three. Bolt count ranges from 8 to 42 depending on length. After welding, sealing surface flatness must be checked and re-machined if required.

Typical Applications

• Hot water or condensate tanks
• Process vessels requiring liquid surface observation
• Silos or closed vessels with side inspection points
• Applications needing greater vertical visibility than circular sight glasses

Selection Criteria

Type 220 is selected where a rectangular viewing window, PN 16 rating, and welded integration into the vessel shell are required. Prior to operation, reinforcement of the vessel wall opening must be verified per TÜV leaflet B9 / AD Merkblatt B9.

FAQ

Is an actuator required?
No. This is a static visual inspection component.

What is checked during maintenance?
Glass, gaskets, bolts, sealing surface flatness, and signs of leakage after thermal cycles.

When is it preferred over circular types?
When a larger linear viewing area of the level or liquid surface is required.