The proper maintenance of flow control structures is crucial to delivering an effective water management strategy.

ECS has the skills and resources to implement a turnkey project including the design, fabrication and installation of new equipment.

With over 25 years’ experience in maintaining water control structures, ECS can provide cost effective solutions that are tailored to each situation.

Penstocks have many applications in the arrest and control of liquid flow. They are used on Waterways, Power plants, Industrial effluent plants, hydro power, Drainage and Flood control as well as being used in large numbers on water, waste water and sewage treatment plants.

Penstocks, unlike valves, are normally fitted into or onto the civil structure formwork either in channels or over an aperture in a wall. The channels and apertures are sized to accept a range of flow situations and the penstocks are required to suit. This requirement alone dictates that they are a bespoke product.

  • Penstock type – Open, shut, modulating, weir
  • Mounting configuration – Channel, Wall
  • Seating direction – On, Off
  • Pressure – Static, Operational
  • Operation/Operator – Manual, Prime mover, (electric, pneumatic, hydraulic)

Our standard range includes sizes from 100mm to more than 4000mm, but each H.C. Waterbeheersing penstock is individually designed to specific customer requirements and a general arrangement drawing produced for approval prior (if required) to manufacture. Following initial selection, thrust and torque values are calculated in order to determine the operating equipment size. Channel penstocks normally operate at door depth pressure, but wall mounted penstocks of both HDPE and fabricated construction can be subject to very high pressures.


Standard HDPE penstocks are either circular or square, however non standard sizes can be accommodated upon request. Fabricated penstocks can be designed and manufactured to any rectangular or square size. We will be pleased to discuss any general or specific requirements you may have.


A range of Handstops and Stoplogs are available for lighter duties and temporary damming applications. These are made to the same high standards as the penstocks and can be provided in a range of materials – please see the relevant section for more details.

W9000 & W9500

Lightweight corrosion resistant flap valves for the prevention of reverse flows.

Flap valves are designed and manufactured for use in modern industrial and domestic effluent environments and for protected river and sea outfalls with gravity flows. Utilisation of the latest materials combined with the strength of steel or stainless provides a range of flap valves having strength and rigidity but which are very sensitive to small differential heads.

Rectangular flap valves are available in sizes 450mm sq up to 3200mm sq as standard. Larger and smaller sizes plus rectangular sizes are available to suit individual requirements. Circular flap valves are available in sizes 80mm bore to 600m bore only.

Pressure Drop across the Flap Valve

The approximate pressure drop across a flap valve is a function of the Velocity head of the fluid passing through it and its size.

  • Corrosion resistance
  • Lightweight
  • Low cracking heads
  • Low maintenance
  • Lower installation costs using expanded anchor bolts
  • Choice of frame material
  • Mechanically fixed renewable seals
  • Custom built to customers requirements

450sq mm up to 2000mm square or any rectangular size within these limitations. Larger sizes can be accommodated depending on pressure and duty.

Standard fixing arrangements is wall fixing on to a flat vertical wall. Note: It is recommended that at least 300mm fall away is provided at the invert to prevent fouling of the bottom of the floor.

Top bottom and side pressed members produce a sloping surface which will guarantee closure in balanced or dry conditions.

Frames and doors are manufactured from mild steel to BS4360 GR43A or stainless steel to BS970 or BS1449 grades 304 or 316.

Mild steel frames as standard are blast cleaned after fabrication to SA2 2/2 minimum quality zinc sprayed to 100 microns nominal thickness (75 microns minimums) etch primed and finished with two coats of coal tar epoxy or high build bituminous paint (potable water), 75 microns per coat.

For sea water applications paint thickness is increased to 225 microns DFT. Stainless steel frames are natural finish.

Is an EPDM (Ethylene Propylene) wiper type seal having an angled lip seal. EPDM (Ethylene Propylene) is chosen for its greater resistance over Neoprene to ultra violet degradation.

The seal is fixed with a corresponding Resistant retaining strip and stainless steel fasteners.

H.C. Waterbeheersing Weirs are available in various forms and are mainly used in surface and process water systems.

H.C. Waterbeheersing tilting weirs provide a very accurate means of controlling water levels upstream.

The tilting weir can be supplied in various sizes and types for water level maintenance and flood alleviation. the weirs can be manually or electrically operated.

The H.C. Waterbeheersing tilting weir is manufactured using stainless steel and hdpe (high density polyethylene).