The GNA HYDROSLIDE is a proven technique for regulating sewer flows. Flows from as little as 5 l/s (80 gpm) may be regulated using valves with a nominal flow diameter of 200 mm (8 in). The float activated mechanism of the GNA HYDROSLIDE regulator is designed to maintain a constant discharge without the use of external energy sources. The flow area is adjusted to perfectly match any increase or decrease in the upstream water level.

Operating Principles

  • The GNA HYDROSLIDE remains in the neutral or fully open position during dry weather flow. As the inflow at the control point increases and exceeds the capacity of the fully opened unit, the increasing water level causes the float to rise, which in turn causes the flow area to be adjusted so that a constant discharge is maintained.
  • The flow rate is maintained constant for head variations of up to twelve (12) times the nominal valve inlet diameter. For a unit with a nominal diameter of 200 mm (8 in) the upstream water level may vary from 0 to 2.4 m (0 to 7.9 ft) while maintaining a constant discharge.
  • The GNA HYDROSLIDE flow passage area is largest at the most critical time; during dry weather flow, at the beginning of a storm event when the sewer lines are being flushed and at the end of a storm event when the sewer lines are emptying, thereby reducing the chances and frequency of blockage.
  • The GNA HYDROSLIDE flow regulator is easy to install in standard chambers through standard circular openings. The installation procedure is simple and is supplied with every unit.

Various Types of Hydroslide Valves

  • STANDARD unit for discharges between 35 and 2000 l/s (1.25 to 70 cfs).
  • VARIO unit which allows the user to change the design flow by 30 %. The unit is designed to handle flows ranging from 35 to 2000 l/s (1.25 to 70 cfs).
  • SELFCLEAN unit which is designed to open automatically and completely should a blockage occur. This unit is designed for flows ranging from 5 to 60 l/s (0.18 to 2 cfs).
  • VERTICAL unit for discharges ranging from 10 to 60 l/s (0.35 to 2 cfs). This unit is designed in such a way as to enable the valve to be opened manually, from the top of the manhole, should blockage occur.
  • MINI unit designed for small head variations. Design flows may vary from 15 to 60 l/s (0.53 to 2 cfs).

Advantages of Hydroslide

  • constant discharge over a variable head range
  • largest possible opening during critical flow periods
  • flow area greater than vortex flow regulators during dry weather periods
  • robust, stainless steel 304 construction
  • no head loss
  • no constriction or diversion of water passage
  • easy and inexpensive to install in new or existing chambers
  • no in-situ adjustment or testing
  • applicable for all types of fluid control
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