My Outfall, My Rules | Customising the Smart Flap Gate Opening Angle
"Please open this outfall to one third." When the river chief's office and the local community made that request, the HIGHDE operations team responded immediately. Some outfalls require the opening of the Smart Outfall System Device (smart flap gate) to be set to an arbitrary angle to meet owner requirements. In this case the rule was: one third open in dry weather, fully open in heavy rain - achieving interception and flood discharge at the same time.
A 22-second remote adjustment
An operator logged into the HAIOT intelligent O&M platform, opened the device's O&M parameters page and changed the opening angle remotely. The adjustment was completed in 22 seconds, with no site visit, no excavation and no interruption of flow. Platform data and the field view showed the gate moving from a wide opening to the requested smaller one.
From open/close to "how far open"
Arbitrary-angle control rests on a complete product capability set. Developed by HIGHDE Intelligent (Guangdong) Technology Co., Ltd., the device combines mechatronics, automatic control, information technology and digital O&M for local and remote outfall management. It provides the four-remote functions (remote signalling, measurement, control and adjustment); opening angle, pipe elevation and first-flush duration are all configurable. A flexible multi-point force-distribution structure keeps loading even and sealing reliable at any angle, and the device opens automatically for flood discharge on power loss, network loss or overpressure.
Trenchless in-situ retrofitting and single-phase 220 V low-power design keep annual electricity cost below RMB 300, making site-specific "one outfall, one strategy" operation affordable and replicable. Hundreds of these devices are now running continuously across the Pearl River Delta.
Core value: "Three Preventions, Two Foundations"
- Prevent overflow - stop dry-weather sewage discharge and keep the river clean
- Prevent flooding - open in seconds when the pipe level reaches its preset threshold
- Prevent backflow - stop river water entering the network, protecting influent concentration and treatment efficiency
- Build an intelligent control and analysis platform - equipment status, risk control, operations and command in one place
- Build a digital O&M system - move from reactive to proactive, raising efficiency and cutting labour cost
Not all gates are the same
- Gravity flap gate - opens passively with flow and weight; no adjustable opening; no active emergency response; simple but limited
- Hydraulic / pneumatic flap gate - single-rod point loading, deformation and poor sealing under high head; loses power and pressure, making low-cost automatic flood discharge difficult; requires three-phase supply and frequent pressurisation, with high electricity cost
- Electric gate - adjustable but slow (about 8 minutes at best); cannot open on power loss or overpressure, risking flooding; demanding installation conditions
- Smart flap gate - freely adjustable opening angle; automatic second-level flood discharge with gravity gate fallback on power loss; trenchless in-situ retrofit, single-phase 220 V, low power and modular maintenance
