Depending on the actual project settings, ANDRITZ HYDRO designs, manufactures and installs pressure conduits both as exposed and embedded penstocks, as pipe bridges or steel tunnel linings. Also competence and long-lasting experience exists in design and construction of bi-/trifurcations and complete, hydraulically optimized manifold systems.
ANDRITZ HYDRO holds world records in penstock design, both with regard to max. design heads (2,070 resp. 1,500 m waterhead) and max. internal diameter (13.26 m). Beside the hydraulic optimization of water conduits, the choice of suitable materials alongwith most economic process technology is a major concern in penstock construction.
ANDRITZ HYDRO has penstock references made of high strength quenched and tempered steels with Y.P. more than 700 MPa, and was also first in using thermomechanically rolled steels with Y.P. up to 550 MPa in penstock construction.
To date, all penstocks designed, manufactured and installed by the present ANDRITZ HYDRO group come to some 500,000 tons.
The size of today’s projects, the necessity of reducing cost in combination with the maximum use of local resources require more and more the outplacing of activities to the project countries.
ANDRITZ HYDRO started to fabricate penstocks directly on site some 30 years ago. A temporary field workshop is set up to house all necessary machinery for production and testing, so that deliveries to site are limited to flat steel plates only. So far, site fabrication for 46 contracts in a total of 170,000 tons have been successfully handled in 20 countries, under most diverse and adverse conditions, from sub-tropical areas to sites located at an altitude of 4,100 meters.
The largest project with site fabrication, in terms of volume, was the Mingtan Pumped Storage Scheme in Taiwan, involving 26,000 tons of steel conduits, penstocks and manifolds.
In many instances, hydro power plants are located in areas where access is difficult. Well-considered solutions and special equipment designed by our engineers help to mask even the most challenging situations. Specially designed temporary erection bridges are among these not-quite-so-usual methods, as well as climbing cranes for a counterlever erection method or mobile ropeway systems for erections in extreme steep terrain.
The heaviest erection units in ANDRITZ HYDRO’s penstock history weighted 285 tons each and were part of the penstock for the Tarbela 3rd Extension Project in Pakistan.
Research and development was always a driving factor also in penstock construction. Hydraulically optimized design for bifurcations and manifold systems, as well as development in fabrication technologies have secured our lead in this field. Just recently, ANDRITZ HYDRO was first applying the TIG-hotwire technology for fully automatic welding of circumferential field joints of steel tunnel linings.
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