Stormwater Flo® vortex valve, have been designed with this goal in mind. This valve is a self activating flow control device that can be installed in either a manhole or catchbasin to restrict site runoff to the
predevelopment rate. It operates by harnessing the energy inherent in the flow field and avoiding the need for moving parts or power. No moving parts mean rquire little or no mainte nance.
The design of the valve is simple, consisting of an intake, a volute and an outlet. Flow is directed tangentially into a volute to form a vortex. High peripheral velocities induce an airfilled core with a resulting back pres sure that reduces the discharge. By using the vortex to control the flow, clear openings are up to 600% larger than
conventional
flow
control
devices, such as sharp edged orifice plates. The larger opening size has two major benefits. Firstly, the larger openings mean the vortex valves are less prone to blockage from the trash and debris often found in urban runoff.
Secondly, the larger openings allow consulting engineers to consider new approaches when designing drainage
Installing a 22 inch Type C Reg-U-Fio vortex vaive into the controi structure at Eastern Maii Office Park, South Portiand, Maine.
systems. For example, installing the valves at points higher up in the drainage network can lead to a reduc tion in the size and cost of downstream
Class H Insulation For Continuous Duty and V.F.D. Applications I Continuous duty and Variable Frequency drive (VFD) rated Insulation system rated to 1802 C (3562 F) Designed to operate over a wide frequency range or speed Special coated, voltage spike resistant, inverter duty motor Exceptional, high performance capabilities F.E. MYERS COMPANY
Myers
Division of Pentair Canada, inc. 269 Trillium Drive • Kitchener, Ontario N2G 4W5
Pentair Pump Group
lei. 519-748-5470 Fax 519-748-2553
^3 engineered pump systems ltd. BRITISH COLUMBIA
ALBERTA
1635 industrial Avenue
115, 9920 - 63rd Avenue Edmonton, AB T6E 0G9
Port Coquitlam, BO V3C 6M9 Ph;(604) 552-7900 Fax:(604) 552-7901
Ph:(780) 439-7800 Fax:(780) 439-7840
Toll Free: (800)668-4533 • Email: epsl@telus.net
pipe work - inlet or source control. Reg-U-Flo vortex valves have a unique S-shaped head/discharge curve, which has been devised from extensive
computational fluid dynamic modeling (CFD) and both laboratory and field testing. The head discharge curve com prises two distinct phases. As the head increases, a transition takes place from the free flow (lower portion of the curve) to vortex controlled flow (upper portion of curve). This unique charac teristic can reduce on site storage vol ume requirements by up to 30%, low ering overall project costs by as much as 50%.
There are currently over 14,000 of these vortex valves in operation around the world, controlling a wide range of flow from 0.15 cfs (4 1/s) to 425 cfs (11,900 1/s). An example of the effective use of the Reg-U-Flo vortex valves can be seen at an office park in South Portland, Maine. The office park con sists of three separate one-story build ings totaling 93,000 sq ft, surrounded by paved parking for 424 cars(an addi tional 183,000 sq ft)for a total of 6.3 acres of impervious surface out of the 10 acre site. The stormwater permit required that post development runoff should not exceed predevelopment runoff rates. The post-development runoff rate was calculated to be 45 cfs
Continued on page 71... 64 Environmental Science & Engineering, March 2005