Exchange of DN1200 pipes for the main water supplying for Central Water-Supply in Warsaw with reconstruction of SW2 chamber.

The range of the works under the contract included:

• assistance during preparation of execution project.
• dismantling of the existing water supplies and molders with maintaining continuity of operation of the whole system
• supply and assembly of pipes and molders DN 1200 with spiral seam, factory protected together with gaskets and screws from the flow-meters chambers (SQ 1.1, SQ 1.2, SQ 1.3) to the chamber SW2. The water-supply pipe's thickness outside the chamber – 16 mm, the pipe's thickness inside – 10 mm.
• cleaning, sandblasting and painting of the spigot at the flow meters in chamber SQ 1.1, SQ 1.2, SQ 1.3 and connecting with the new water supply with the STAUB coupling.
• dismantling and assembly of flow meters
• anti-corrosion protection of the pipes and molders – 3 LPE
• making of workshop welds in class B
• making of assembly welds in class C
• exchange of the DN 1200 pipes in SW 2 chamber, 10 mm thickness, anti-corrosion coating – paint
• exchange of the pipes towards chamber A – echange finished before the chamber, making of the joint with existing pipeline,
• supply and assembly of the connecting flanges DN1200 with gaskets
• demolition of the chambers on the steel – cast iron pipelines connections
• assembly of the fittings
• assembly of DN 1200 steel joints and pipe crosses in SW 2 chamber,
• supply and assembly of SIKA seals at the walls crossing (without sleeves)
• ground works and reconstruction of the area with exchange of the soil,
• securing of the existing underground installations not subject to exchange
• securing of the trenches
• assembly of the water-supply pipelines' vents in SW 2 DN 150 chamber.
• assembly of cover plates on SW 2 chamber,
• isolation on SW 2 chamber
• assembly of 2 hatches on SW 2 chamber DN 600
• exchange of the baffling with assembly lever in Z19 chamber
• welding the sleeves on existing pipeline in order to adopt the existing pipeline to the new one in SW 2 chamber. Works done on the outlet of the pipeline, behind the SW 2 chamber towards the Z9A chamber on the length of 1 meter behind the chamber.
• Preparation of the quality assurance plan (QAP) – 4 copies
• Preparation of the WPQR (Welding Procedure Qualification Record) – 4 copies
• Preparation of (WPS) Welding Procedure Specifications – 4 copies
• sandblasting of cover sleeves 1, SQ1.2, SQ1.3, Z19
• anti-corrosion coating on sleeves 1, SQ1.2, SQ1.3, Z19
• preparation of the irrigation of the trench – prior to the works the wellpoints have to be supplied to the site
• preparation of the execution plan prior to the start of the works, considering the stages aspect of the works covering exchange of the DN 1200 pipes.
• supply and assembly of the SW 2 chamber's drainage – flushing pipes - PVC-U S-class DN 400 pipes – outside SW 2 chamber, inside – steel pipes DN 400.
• supply and assembly of concrete wells for SW 2 drainage.