The Foundation of Wall Penetration: The Rigid Casing
In civil engineering, the most common way to allow a pipe to pass through a concrete wall is by using a Rigid Waterproof Casing. While the flexible model handles movement and vibration, the rigid casing (Type A/B/C as per 02S404) is the heavy-duty standard for structures where the pipe and wall remain static.
1. The Power of the Water-Stop Ring (Wing Ring)
The most defining feature of a B-NAI rigid casing is the Water-stop ring (wing ring) welded to the outer surface.
Mechanism: When the casing is cast directly into the concrete wall, the wing ring creates a long, winding path that water cannot easily bypass. It significantly increases the contact surface, preventing seepage along the outer wall of the sleeve.
2. When to Choose Rigid Over Flexible?
While flexible casings are great, they are more expensive. Rigid casings are preferred in:
Static Structures: For walls that do not experience significant settling or seismic movement.
Non-Vibration Pipes: For gravity drains or pipes not connected to heavy machinery.
Cost-Sensitive Projects: It provides a reliable, long-term seal at a fraction of the cost of mechanical-seal flexible casings.
3. B-NAI Quality: Welding and Coating
A leak in a buried casing is a nightmare to fix. That’s why B-NAI uses full-penetration welding for the wing rings and applies a thick layer of anti-corrosive primer or epoxy. Our casings are designed to last as long as the building itself, resisting corrosion from soil and moisture for decades.
