Oblong and special windows
Non-circular windows — only types and sizes with documented data.
An oblong (oval or rounded-rectangle) window widens the observation zone along the vessel — for example, to watch the medium level in a mixer or several zones through one window.
The category collects only types with documented data: oblong windows must not be assigned DIN 28120/28121 designations, which apply to circular fittings. Actual dimensions and versions follow the manufacturer documentation.
What belongs to this category
- Oblong windows for walls and covers with documented dimensions.
- Special viewing shapes (wide, sector windows) with confirmed data.
What does not belong here
- Circular DIN 28120/28121 fittings.
- Non-pressure covers with glass — a separate category.
- Arbitrary “sizes” without a primary source.
How to choose an oblong window
- Step 1
Define the zones that must be observed simultaneously: the window length is set by the task, not by “the more the better”.
- Step 2
Assess the effect of the cut-out on wall stiffness — this is a question for the vessel designer.
- Step 3
Ask the manufacturer for the actual dimensions, corner radii and permissible operating conditions.
- Step 4
Enter the measured values into the RFQ sheet, including the glass outer diameter or length for replacements.
Series and constructions of the section
The “Oblong windows” series explains the construction features; there is no universal standard for the shape.
Sources
- ACIopen the sourceTechnical review: 2026-11-04