Chezy Siphonic Rainwater Drainage System
An engineered full-bore rainwater drainage system designed to remove roof water rapidly while reducing pipe sizes, vertical droppers, roof penetrations and underground drainage compared with conventional gravity systems.
More Drainage Capacity with Less Pipework
Gravity Drainage
- Air and water flow together inside the pipe.
- Larger pipe diameters and multiple vertical droppers.
- Horizontal pipe gradients are required.
- More underground drainage and building space are needed.
Chezy Siphonic Drainage
- Controls air entry for full-bore water flow.
- Smaller pipe sizes and fewer vertical droppers.
- Zero-gradient horizontal pipework.
- Reduced roof penetrations and underground drainage.
Performance
Up to 10× Faster Water Removal
Catalogue positioning for high-discharge siphonic flow versus gravity-assisted drainage.
Cost & Space
Up to 30% Project Cost Saving
Simpler Network
75% Fewer Pipes
Fewer droppers can reduce roof openings, pipe congestion and underground pipework.
Building Design
Suitable for Complex Roof Shapes
Water Reuse
Rainwater Harvesting Ready
Assurance
12-Year System Warranty
System Services & Products
With Chezy, your rainwater drainage systems are solved without issues. Our team accompanies you from planning stage, from design including installation and maintenance service.
With Chezy, your rainwater drainage systems are solved without issues. Our team accompanies
you from planning stage, from design including installation and maintenance service.
Solution Development
Our application engineering team provides tailored drainage solutions using precise calculations and advanced software. We can also customize solutions to meet specific project requirements.
Installation Team
We offer turn-key installations managed by our own specialists. This guarantees that the installation adheres to design and drawings.
After Sales and Warranty
After installation and validation, Chezy provides a 12-year warranty for added peace of mind, backed by responsive after-sales service and technical support.
Four Stages to Full-Bore Siphonic Flow
The water flow through Chezy siphonic system can be summarized in four steps.
Gravity Flow
During light rainfall and the initial or final stages of a storm, air and water enter the system together, creating a conventional gravity-flow pattern.
Plug Flow
As rainfall increases, hydraulic plugs form inside the pipe, creating pressure-driven flow and triggering the siphonic action.
Bubble Flow
As the pipe fills further, air bubbles are carried through the water flow, helping the system transition toward full siphonic operation.
Full Bore Flow
During heavy rainfall, the pipe becomes fully primed and operates under negative pressure. High-velocity flow delivers maximum drainage capacity and high discharge performance.
Engineered as One Integrated Drainage Solution
Chezy siphonic roof rainwater system generally consists of the siphon rainwater collector, pipes (connecting pipe, hanging pipe, stand pipe, discharge pipe), pipe fittings, and a fixing system.
The fixing system consists of a suspension fixing system (m10 mounting piece, m10 screw rod, small riding clamp, hanging pipe clamp, triangular pin, square steel connector, square steel), and a stand pipe fixing system (m20 mounting piece, m20 screw rod, stand pipe clamp).
Siphonic Roof Collector
The collector is the starting point of the system. Its air-water separation and anti-vortex design helps initiate full-bore flow while restricting air entry.
304 stainless steel collector
Cast aluminium grille cover
Anti-vortex design
Corrosion resistant
HDPE Pipework & Supports
HDPE pipework provides a lightweight, corrosion-resistant and fusion-welded drainage network supported by engineered clamps and fixing systems.
Fusion-welded connections
Flexible and impact resistant
Negative-pressure resistant
Engineered support spacing
From Roof Plan to Installed System
Project Review
Hydraulic Design
Drawings & BOQ
Our Project References
Please email us marketing@chezy.com.my to get the project reference.
Explore the Full Siphonic Rainwater Drainage Catalogue
Download the complete catalogue for technical tables, formulas, component details, installation information and additional project references.