Frequently Asked Questions
Q. What is a Hydro-Brake Optimum®?
A. A Hydro-Brake Optimum® is a no-moving parts, self-activating vortex flow control. When the upstream water level reaches a suitable level the water entering the unit spins within it. This causes the formation of an air-filled core which takes up a significant proportion of the outlet of the unit. Water discharges around the periphery of the outlet from the Hydro-Brake Optimum® only which enables the use of a significantly larger outlet than if a simple orifice was used. The outlet cross-sectional area can be significantly greater than that of other flow controls required to meet the same head / discharge condition.
Q. Are all vortex flow controls the same?
A. NO! The performance characteristics of the Hydro-Brake Optimum® are unique and have been independently accredited by the BBA and WRc. We pride ourselves on being able to deliver the very best hydraulic performance from our products, the value of which is realised through the efficient design of stormwater and wastewater infrastructure.
Switching from a Hydro-Brake Optimum® to an alternative vortex flow control device may remove added value already factored into the design. This can lead to inadequate storage capacity onsite, resulting in:
- Increased flood risk (onsite and downstream).
- Premature flooding of the storage facility.
- Unauthorised over discharge from the site
The smaller openings and outlets on other products can lead to an increased risk of blockage, and the inferior materials used by some suppliers can lead to structural failure resulting in installers having to spend a lot of time and money rectifying problems and repairing their damaged reputation
Q. How much maintenance does a Hydro-Brake Optimum® require?
A. Quite simply, this is site-dependent. It depends upon the size of the Hydro-Brake Optimum® itself (the larger the unit the less the likelihood of a blockage occurring), the nature of the influent (for example a unit of a given size would be more susceptible to blockage were it placed on a foul system than on a purely surface water system) and physical characteristics of the control chamber itself (adequate benching is essential). We have minimum recommended sizes for use within surface and foul water systems (contact Hydro for more information).
Q. Why is there a door on the front of the unit? Can I open this to increase the flow rates?
A. The door is intended to allow an emergency drain down of the manhole chamber or tank in case of a blockage at the inlet of the Hydro-Brake Optimum® unit. It can be operated from the surface, allowing the chamber to be emptied prior to freeing the blockage from the inlet of the unit. On release of the pull cable, the door will close under its own weight and does not require any complicated mechanism that may contribute to debris being caught around the unit.
The door should only be opened in the event of a blockage and must be closed following maintenance. Opening the door during normal operation will prevent the unit from operating as a vortex flow control and will pass more flow than permitted under the unit design. This could constitute a downstream flood risk.
Q. Do they work under downstream surcharge conditions?
A. Yes, but an air vent pipe may be required to ensure that the air core can form. The flow through a Hydro-Brake Optimum® is dependent upon the physical size of the unit itself and the differential head of water acting upon it. Please contact us for further information
Q. How much clearance must I allow downstream before I can fit another valve, control or device, put a bend in the pipe or change pipe diameter?
There is a requirement of all vortex flow controls to maintain a downstream clearance to allow the vortex to fully form. This clearance is typically around 3m, or 10x the outlet diameter of the unit (whichever is the greater).