Water pipeline - Handling and storage of coated pipes

GENERAL INFORMATION When handling coated pipes, pay special attention to the following:
- plan storage, lifting and transport in advance
- make sure there is sufficient and correct auxiliary equipment
- carry out an acceptance inspection
- be careful not to damage the pipe ends
- support and bind the bundles properly
- use a sufficient number of appropriate packers and wooden bases.

See also SSAB’s handling instructions for pipe products and the following publications:
- API RP 5L1, Recommended Practice for Railroad Transportation of Line Pipe
- API RP 5LW, Recommended Practice for Transportation of Line Pipe on Barges and Marine Vessels. .
To make it easier to handle pipes, we can deliver base packers, lifting lines, end stoppers and bevel protections.


External sheathings

PE coating

The line pipes for ground installations are usually furnished with an external sheathing of polyethene. Usually this is a so-called 3-layer sheathing for which a thin epoxy layer is first melted onto the shot-blasted steel pipe, over which the coats of adhesive and polyethylene are then applied (Figure 1). When the coatings cool down, bonds form between different components, which ensures the high level of adhesion and good mechanical and chemical properties of the coating.

The epoxy layer protects the pipe against corrosion. The polyethene coating protects the epoxy layer against damages. The adhesive layer functions as a glue between the epoxy and polyethene layers. If the polyethene layer remains intact there is little or no corrosion. The coating also protects the pipe during transport and installation.

The external coating can be damaged by mechanical impact, chemical substances, UV light and abrasion. Due to the different thermal expansion of the coating material and steel, the long-term storage of pipes in sunshine may decrease the adhesion of the coating in pipe ends.

Protective painting and storage lacquer

Protective painting and storage lacquer are intended only for temporary protection during storage. They must be removed before the actual primer coating and coating by means of shot blasting, for example.

Coatings of pipe fittings

Pipe fittings refer to the fittings of pipes for water mains such as fabricated bends and tee fittings. Pipe fittings are now most commonly coated with polyurethane. Polyurethane provides excellent protection against mechanical wear during the storage, transport and installation of pipes.


Internal coatings Pipes for water mains

Steel pipes for water mains and their components are supplied with a lining of concrete or epoxy.

The concrete cast used consists of
• SR-cement
• Dried, pure natural sand
• Tap water The thickness of the concrete lining is 7–15 mm, depending on the diameter of the pipe.

Ferric hydroxide, which forms on the interface of the concrete lining and steel pipe, protects the pipe against corrosion and fastens the concrete firmly to the steel. Minor cracks appearing in the concrete during e.g. transport or installation are not dangerous, because when exposed to water, concrete expands and thus fills the minor cracks. If necessary, the concrete can be moistened by watering with tap water. The epoxy lining of pipes for water mains is made of foodquality 2-component epoxy that is practically solventfree. The lining has good wear resistance and gathers no sediment. The thickness of the lining is about 0.5 mm.

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