In the early days IHP would fabricate penstock pipes at fabrication shops set up near the site of the respective hydroelectric project.

However in the year 1958 when the Company secured a prestigious contract for fabrication, supply and erection of steel liners for Head-race and penstock tunnels of underground Koyna Hydro-electric project, not far from Pune, it was decided to set up a very modern and well equipped penstock fabrication plant at Hadapsar, in technical collaboration with world famous Swiss Companies namely M/s Giovanola Freres SA & Zehokke SA of Zurich and M/s Chicago Bridge & Iron Co. Ltd. of USA.

The factory is equipped with sophisticated machinery and equipment required for the fabrication and erection of penstocks and penstock specials like expansion joints, Wye pieces, bulk heads and other products like LPG Storage Tank, Boiler Shells, Cement Kilns etc.


A Penstock is a high pressure steel pipeline that carries water from the storage reservoir to the turbines and is a vital element of hydro-electric projects. The design, fabrication and erection demand a high degree of skill. Until the late thirties, penstock and even technicians had to be brought from abroad. In 1937, however the company decided to take up the challenge of manufacturing penstock in India and offered its services to the Madras Government for the prestigious Papanasam Hydro project. This order was secured against heavy odds and executed successfully to the satisfaction of the authorities. The successful completion of the Papanasam Hydro project led to further orders from erstwhile Madras and Mysore Governments to fabricate and supply penstocks for Moya and Mahatma Gandhi Hydro Projects. Since then the company has established a long track record for designing, fabrication and erection of several penstock projects all over India and neighboring countries. A little over a hundred a thirty thousand tones of penstock have been supplied and installed by the company to various hydro-electric projects generating about 12,000 Megawatts of power per day.


Quality control is an essential part of fabrication and erection of penstocks. Depending upon the basic steel material used for penstocks, the matching welding consumables are selected. Particularly, while using 'quenched' and 'tempered' steel, electrodes with low hydrogen content are to be baked and kept dry before use and while welding this steel, it is very essential to strictly control the pre-heat temperatures, inter-pass and post-heat temperatures. The company has wide experience in the welding of special steels requiring rigorous quality control procedures and our technicians have mastered these techniques. The Company's engineering experts ensure the high quality of welding by inspecting every weld by dye-penetration check, ultrasonic testing, magnetic particle testing and radiography. The welded pipes are subjected to hydrostatic test before painting and despatch to ensure pipes are strong and safe enough to withstand design water pressure.


The design, fabrication & erection of extra high tensile steel Penstock Specials, capable of withstanding very high pressures is a challenging job. IHP technicians have, during the past several years successfully designed, fabricated and erected various types of specials like ring girders, rockers, transitions, bell mouths, expansion joints, flexible couplings, wyes (bifurcation and trifurcation pieces), surge liners for surge tanks, bulkheads etc.


The IHP's Penstock Division, with its rich experience and unmatched expertise in fabrication, welding technology and non-destructive testing has taken up the fabrication of centrifugal baskets for sugar plant machineries, shells for mill and cement kilns, LPG tanks and several other job works and is geared to serve vital needs of the country in several other fields too.

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Product Catalog

Highlighted projects

Project Quantity
Sharavati Stage II 9929 MT
Nathpa Jhakri 8800 MT
Koyna Stage IV 7435 MT
Bhira 5950 MT
Narmada 4700 MT


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