Adjusts overflow heights, increases storage volume, hydraulic or external energy-free

The Challenge

Storm reten­tion tanks and sew­er net­works have to be equipped with spill over­flows. In the event of heavy rain­fall and if the tank is full, the over­flows divert excess water into the adja­cent water­course etc. The upper edge of the over­flow weir is the max­i­mum stor­age of the tank. The area above the over­flow weir is used by the water over­flow­ing, the height of which increas­es as flow increas­es due to head­loss. The  Stein­hardt HydroBend Weir Gates, when fit­ted on the over­flow weir, allow this over­flow height  to be utilised and retained increas­ing the vol­ume of the tank.

The Way

The HydroBend vari­able weir is nor­mal­ly set in its upright posi­tion and will hold back water until an over­flow occurs. As the flow rate of the over­flow increas­es, the weir will start to col­lapse; this action main­tains the top water lev­el of the upstream water. The instal­la­tion of the HydroBend Weir Gate on the over­flow weir increas­es the water lev­el by the val­ue of the head­loss due to flow rate. The HydroBend Weir Gate col­laps­es as the over­flow occurs, main­tain­ing the nor­mal top water lev­el. When the over­flow stops the HydroBend Weir Gate returns to its upright posi­tion and retains its height in addi­tion­al storage.

The Solution

HydroBend Weir Gates are mount­ed on the spill­way / over­flow weir and they are hinged at the bot­tom. If the water lev­el exceeds the weir height, the weir low­ers main­tain­ing a con­stant top water lev­el. The water is dis­charged over the upper edge of the gate.  As the over­flow rate sub­sides the HydroBend returns to its ver­ti­cal posi­tion. In doing so, it retains its height in addi­tion­al stor­age with­in the tank.

HydroBend Weir Gates can be con­trolled elec­tri­cal­ly, hydrauli­cal­ly or with­out a pow­er source using a counter-bal­ance sys­tem. The weir gate, oper­at­ed by adjustable coun­ter­weights and cables, is low­ered and raised in pro­por­tion to the water level/water pres­sure. In the event of down­stream sur­charge the HydroBend will still col­lapse pro­vid­ing there is still a dif­fer­en­tial water lev­el to per­mit dis­charge. Alter­na­tive­ly, the weir gate can be pro­vid­ed as a flood pro­tec­tion valve. In addi­tion to the dis­charge fre­quen­cy, the over­flow quan­ti­ty can also be com­put­ed by means of an option­al incli­nome­ter. Instal­la­tion can also take place in open chan­nels lead­ing to the treat­ment plant. We would be pleased to pro­vide fur­ther information.

The Advantages

• acti­vates stor­age volume
• keeps water lev­el constant
• reduces dis­charge frequency
• pro­tects bod­ies of water
• no exter­nal ener­gy required
• mod­u­lar structure
• reli­able operation
• retro­fittable
• low-main­te­nance
• robust stain­less-steel construction
• option­al back­pres­sure compensation
• option­al back­pres­sure safeguard
• option­al remote effect, angu­lar measurement