What’s the difference between a Vortex and Orifice Flow Control system?
Vortex Flow Control Valves and Orifice Flow Control Chambers are used to support the management of Sustainable Drainage Systems (SuDS) and the sewer infrastructure as part of a designed attenuation system. Both systems are highly effective but if you’re considering which one to use on your project, what’s the difference? Here’s a useful guide.
What are the systems used for?
Both systems are used alongside an attenuation system to control the flow of stormwater and help prevent flooding. With the increased acreage of hard-surfaced, urbanised land in the UK and the increased cost of developed land, Sustainable Drainage Systems (SUDS) are becoming an increasingly important topic with developers and is being driven by the UK government.
What is a Vortex Flow Control System?
A Vortex Flow Control System is a self-activating device based on the principle of vortex hydrodynamics – it uses hydraulic effect without the need for moving parts or power to control the flow of stormwater.
When the device is subjected to sufficiently high upstream water levels, a vortex is induced in the flow. The vortex motion results in significant energy loss, thereby creating a pressure drop across the device and restricting the discharge leaving the outlet.
What is an Orifice Flow Control System?
Orifice Flow Control Systems are pre-fabricated structured twin-wall chambers that incorporate an integral orifice plate flow control.
Orifice plates are used as restriction devices to regulate fluid flow or reduce the flowing pressure downstream of the orifice plate. The use of a fixed restriction orifice can be beneficial and economic by reducing the demands on other flow system components. These systems also allow the precise control of discharge rates.
What’s the difference between the two systems?
Both systems are extremely effective in helping to control the flow of stormwater. Which one is best is dependent upon your specific application and our team of specialists are happy to advise you on this. Generally, though, we tend to find that the Vortex system is best suited to larger projects whilst Orifice suits smaller ones. Here are some of the key differences:
- The outlet of a Vortex Flow Control Valve can be up to 6 times larger than a traditional orifice plate, significantly reducing the risk of blockages and the associated maintenance costs.
- A Vortex Flow Control has much less energy than an Orifice Flow Control so will cause less scouring or physical damage to downstream features like sensitive wetlands, ponds, basins, watercourses or sewer infrastructures.
- Minimal maintenance is required with a Vortex Flow Control because they are self-activating with no moving parts or power supply requirements.
- In contrast to a Vortex Flow Control Valve, an Orifice Flow Control Chamber is delivered as a one-piece unit ready to install, which means reduced installation time and costs.
- An Orifice Flow Control Chamber can reduce the land requirement and make significant savings on the cost of installing and maintaining a larger flow control chambers at the final outfall of the site.
- An Orifice Flow Control Chamber is strong but lighter in weight than a Vortex Flow Control, minimising health and safety risks.
How can we help?
We provide a range of Vortex Flow Control and Orifice Flow Control Systems to suit your needs and budget. Our team of specialists can provide you with expert advice on which system would be best suited to your application. Please call us today on 0121 351 3230.