Introduction
Howell-Bunger valves (also widely recognized as hollow-jet or fixed-cone discharge valves) manufactured by Di Nicola represent the state-of-the-art solution for the safe and precise regulation of water release from dams, reservoirs, and large water storage assets. Engineered explicitly as free discharge valves, they are widely utilized as reliable turbine bypass systems, reservoir bottom drains, or continuous discharge flow control systems. Due to their unique internal architecture and contoured ribs, the discharging water jet expands into a broad conical angle that breaks up into a fine spray, effectively dissipating massive hydraulic energy while eliminating dangerous operational vibration problems.
Key Features
Exclusive and innovative “free spring sleeve design” that completely prevents sleeve jamming or operational blocking caused by adjusting spring failures common in competitor designs, integrated contoured inner body ribs hydraulically optimized to mitigate severe vibration issues during atmospheric discharge, high-integrity metal/EPDM encapsulated O-ring seating mechanism achieving a completely drip-tight shut off, cylindrical sleeve obturator utilizing precise linear motion for accurate and smooth flow parzialization throughout its operational range, robust framework engineered for the optional installation of a jet-guide hood to concentrate and direct the downstream water flow into a tightly controlled diameter.
Technical Data Table
Applications and Benefits
- Dam bottom outlet and reservoir draining: High-capacity continuous flow regulation to maintain safe water levels under severe hydrostatic heads;
- Hydro turbine bypass operations: Immediate and safe diversion of high-velocity flows without inducing destructive water hammers or dangerous pipeline surges;
- Versatile installation configurations: Standard open atmosphere discharge, specialized concentrated flow via hood guide pipe, submerged configuration for underwater energy dissipation, or vertical discharge into closed chambers;
- Cavitation and cost mitigation: Advanced internal flow design eliminates cavitation phenomena, drastically reducing long-term operation and routine maintenance costs.
Why Choose Our Products
The company Di Nicola builds bottom valves Howell Bunger type open drain, Room dissipation, or discharge submerged under construction EN S275J0 steel and stainless steel with high nickel content of more than thirty years with sizes between 200 and 2000 mm and nominal pressures from 2.5 bar to 100 bar. The bottom valves type Howell Bunger Di Nicola drives are built with mechanical, electrical and hydraulic and respond to major international standards such as EN 593, EN ISO 1074-1, EN ISO 1074-2, DIN 3202, BS 5150, ISO 5752, ASME B16.10. With marked according to EN ISO 19 and flanges according to EN 1092-2, ISO 2531, BS4504 test according to EN 12266-1. Nicola has assets of more than 30 installations in over 10 different countries in and outside Europe with sublime results. The bottom valves type Howell Bunger Di Nicola can be provided with a series of accessories such as universal joints, flow conveyors, sinks flow, columns of maneuver, position indicators and other.
Contact our engineering department today to request a tailor-made sizing study and configure the ideal Howell-Bunger valve matched to your specific project and layout requirements. Download our official technical catalog to further explore detailed discharge coefficient charts, pressure factor curves, and extensive hydraulic model data.
