Hydropower plant: Penstock

Diameter ND 36″ (950 mm) and 24″

Both with restrained joint and 25 bar pressure


QUETZAL – Guatemala



The project consists of a low pressure line up to a storage tank  where it connects to the ND 36″ ductile iron pipe from CONSTRUTEC DUKTIL.

The conduction runs through a steep orographic area, complicated for any alternative that requires concrete blocks due to its high cost. This high cost is given by the complex conditions of the pipeline installation, especially in the final section of the connection with the powerhouse, where a branch is required to split the pipe and connect with the two turbines. All this in a section of unevenness and without the need for anchoring.


In this hydroelectric central, CONSTRUTEC’s engineering services participated in the design of the pipeline and system modeling with specialized software. The storage tank with all its elements was designed. Furthermore, detailed engineering, installation manual, and supervision of the construction phase of the pipeline were made. The criteria for the pressure test were defined.

CONSTRUTEC supplied all the necessary equipment to achieve a perfect operation: Ductile iron pipes in ND 36 ″ + 24 ″, as well as all their bends, tees, connection terminals with storage tank and connection with the powerhouse, including all necessary disassembly valves and spools.

The entire pipeline was executed with double-chamber locking system pipe (Lok & Play) from USA and dimensional criteria pursuant to AWWA standard. The inner lining chosen has been Portland cement with a Seal coat. The exterior protection used is zinc 200 g / m2 and a black bitumen finish layer, a classic in iron pipes that covers 90% of the soil types where the pipes are installed.

The keystone in the project success

  • 40% reduction in the initial budget which included anchors, providing greater safety, useful life and long-term profitability, without maintenance cost.
  • Supervision and control up to the pressure test by the design team itself

Benefits and advantages of our solution:

  • Does not require concrete blocks (No expansion joints)
  • Very high placement performance: Lok & Play
  • Very complex areas and extreme slopes
  • Supports very high pressures
  • With trench or without trench
  • Seamless, even in a waterlogged trench
  • Minimal head loss
  • Operation guarantee, without breakdowns or service interruptions
  • Obsolete steel pipe replacements