Aluminium Funnel Baffle Siphon Drain with Stainless Steel Roof Outlet for DN50-DN400 Commercial Steel Buildings

The Vantra Aluminium Funnel Baffle Siphon Drain, manufactured by Guangdong Wanquan, is a high-performance stainless steel roof outlet engineered for commercial steel building drainage systems. Optimised for large metal roofs of commercial properties, this siphon drain delivers stable, efficient rainwater removal under heavy rainfall, making it a trusted choice for modern commercial construction projects.

The aluminium funnel baffle and stainless steel main outlet are the core of its superior performance. The precision-crafted aluminium baffle suppresses vortex formation and restricts air ingress into the pipeline. By minimising air mixing, the drainage system quickly establishes and maintains a full siphon effect, achieving a far higher continuous flow rate than conventional gravity drains. This powerful draining capacity effectively eliminates standing water on large, low-slope commercial steel roofs and prevents roof ponding risks during storms.

• High drainage efficiency
• Fewer drainage pipes
• Save space

Built for long-lasting performance in harsh outdoor environments, the stainless steel outlet flange and body offer outstanding tensile strength, rust resistance and chemical stability. The aluminium baffle resists UV degradation and temperature cycling, without warping or cracking under long-term sun exposure. The matched elastic sealing gasket forms a tight waterproof joint between the drain and roof waterproof membrane, stopping water seepage that could damage interior commercial spaces and finishes. Every unit undergoes strict factory performance testing, including flow calibration, watertight pressure tests and load inspection to guarantee consistent operational reliability.

Its integrated baffle structure also provides excellent anti-blocking performance. It intercepts leaves, gravel and construction debris before they enter the HDPE siphon pipeline. This greatly reduces pipeline clogging, cuts downtime and lowers routine maintenance costs for busy commercial buildings such as exhibition halls, shopping centres and transit terminals.

Designed to fit standard steel roof installation procedures, this siphon outlet features a bolted connection design for fast, neat installation. It is fully compatible with HDPE siphonic pipework and available in multiple standard sizes to match different rainfall load calculations.

As a professional drainage manufacturer based in Guangdong, Guangdong Wanquan provides technical support, drawing guidance and customisation services for global engineering partners. If you require high-performance siphon drainage outlets for your commercial steel roof projects, our Vantra siphon drains are the reliable solution.

We accept OEM & ODM orders as per the customer's drawing; OEM service is available. We can also put your logo on our products. 100% test before shipments.

Die casting offers tolerances ranging from +/-0.003″ to 0.005″ per inch, and even as tight as +/-0.001″ depending on customer specs.

Die cast parts can be produced with smooth or textured surfaces and a variety of paints and plating finishes. Finishes can be chosen to protect from corrosion and improve cosmetic appearance.

We usually charge a relevant sample fee. The sample fee is refundable when the order reaches a certain quantity. Make sure our product is what you need. Sample lead time is usually 2–4 days, and 10–12 days for batch goods.

It is a twenty-four-hour service that allows you to send information at any time of the day or night. We will reply to you within 12 hours.

We have our own various patents and hydraulic calculation book. We have a design team to make customized products; we can also design products as per your description.