Steel pipes [German version]

Table of contents

General:
Product information
Packaging
Transport
  Container transport
  Cargo securing


Risk factors and loss prevention:
Temperature Odor
Humidity/Moisture Contamination
Ventilation Mechanical influences
Biotic activity Toxicity / Hazards to health
Gases Shrinkage / Shortage / Theft
Self-heating / Spontaneous combustion Insect infestation




Product information

Product name

German Rohre, Stahlrohre
English Steel pipes
French Tubes
Spanish Tubos
CN/HS number * 73 ff.


(* EU Combined Nomenclature/Harmonized System)



Product description

Pipes are long hollow articles of various cross-sectional shapes supplied as straight lengths or in coils. They are produced by casting, rolling, pressing, drawing, electrolysis or by welding and subsequent curling of strip metal. The cross-section is constant at right angles to the longitudinal axis. Metal pipes may also be subdivided into seamless, butt-welded and welded pipes.


Quality / Duration of storage

Steel products are particularly susceptible to deterioration due to corrosion or may often require elaborate treatment before being used or further processed.

One particularly frequent cause of damage is rust due to seawater, rain, condensation water in the means of transport, cargo sweat or condensation inside the packaging. Unsuitable means of transport, ships with poor hatch covers or without ventilation facilities, damaged containers, uncovered railroad freight cars and trucks, incorrect storage in the open, use of unsuitable tarpaulins, exposed loading in wet weather conditions, and variations in temperature and climatic conditions during long voyages may result in rust damage.

The degree of rusting of steel consignments should be recorded in the shipping documents before acceptance of the consignment, possibly using the following definitions:

Wet before shipment
Partly rust stained to rusty
Gear marked
Contaminated by foreign substance
Contaminated by saltwater
Chafed in places
Packing torn exposing contents


The AMERICAN RUST STANDARD GUIDES are mainly used to describe the condition of hot-rolled steel or uncoated pipes.

Pipes are mainly stored in the cantline in several layers. In this case, the pipes must be prevented from rolling with wedges and friction-enhancing materials (e.g. nonslip mats) should be laid between the pipes. Stacking height is here determined by the wall thickness, diameter and coating of the pipes. Overstowing may result in distortion (ovalization) of the pipes.


Intended use

Depending upon their diameter, pipes have many different applications. Pipes are accordingly used, for example, for producing pipework, gas lines and boiler tubes, furniture, bicycle frames etc..


Figures

(Click on the individual Figures to enlarge them.)

Figure 1

Figure 1
Figure 2

Figure 2



Countries of origin

Trade in steel and steel products primarily flows:

within the EU
Eastern block --> EU countries and USA
EU countries --> USA
Japan, Korea, India, South Africa, Brazil --> EU countries and USA


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Packaging

Depending upon the diameter of the pipes, they are transported individually (large diameter) or in bundles (small diameter). Bundled pipes are held together with transverse metal strapping or wire. Care must be taken in this case that the strapping is very tight, so that the individual pipes cannot rub against each other, so causing damage. Depending upon the route and duration of transport and frequency of handling, bundled pipes may, for example, be wrapped in plastic/jute fabric and be provided with sheet metal protectors at the bundle ends and at slinging points.

Special pipes should be protected from corrosion and are generally coated or packaged in appropriately lined boxes or wood/corrugated board structures.

Special coatings, such as PE, must be padded so that the protective layer is not damaged.

Pipes (medium size pipes) with sensitive inner walls, threads or chamfers (beveled edges) are provided with protective plastic or metal end caps.

Figure 3

Figure 3


Marking of packages
Mark07.gif (2224 bytes)

Keep dry



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Transport

Symbols

Symbol, general cargo

General cargo



Means of transport

Ship, truck, railroad


Container transport

Pipes may be transported using the standard container. Particular attention must be paid to cargo securing in container transport. If the pipes are able to move longitudinally because they are inadequately secured, there is a risk that individual pipes will pass through the front end wall of the container.


Cargo handling

Pipes must be handled carefully owing to their sensitivity to mechanical damage. Losses are frequently caused by improper handling and the use of incorrect cargo handling equipment. Pipe ends may, for example, be damaged by notching or bruising, which makes them unsuitable for their intended use and entails reprocessing.

Careless handling may result in damage to protective layers (e.g. zinc), which consequently lose their protective function, so causing corrosion.

The permissible loading capacity of the slinging and handling equipment and the lifting capacity of the load suspension equipment must also be taken into account.

Cargo handling should be carried out in dry weather or under cover, since the product is highly susceptible to corrosion.


Stowage factor

Highly variable, depending upon packaging, dimensions and weight, e.g.:

1.04 m³/t (steel pipes) [1]



Stowage space requirements

Due to its weight, this cargo is generally stowed in the lower hold. The loading capacity of the decks must be taken into account when drawing up the stowage plan.

If pipes are secured with wedges to prevent rolling, care must be taken to produce the wedges such that the underside of the wedge (2) and inside of the wedge (1, the side facing the coil) are cut across the grain and the outside of the wedge (3, which is nailed) is cut with the grain. The minimum effective height for transverse securing should be at least 1/8 of the pipe diameter and the wedge width at least 2/3 of the wedge height.

keil.jpg (1995 bytes)


Due to the risk of corrosion, this cargo should always be stowed in holds which are protected from the weather or it should be covered in another way to provide appropriate protection. Corrosive contaminants must be absent from the holds.


Segregation

Cloth or plastic tapes

Oil-based paint and wooden dunnage may damage coated pipes.


Cargo securing

Comply with the consignor's/manufacturer's loading instructions in order to avoid damage due to mechanical stresses.

Truck:

Pipes must be transported in vehicles having a headboard and side walls (stanchions) with sufficient strength and loading capacity. Nonslip material must also be placed under the load and between layers. Gaps between the load and the headboard and side walls should be avoided. Gaps in the longitudinal direction in particular may result in slippage of the tubes on hard braking. If gaps in the load are unavoidable for reasons of proper load distribution, the load must be secured in accordance with anticipated accelerations by direct securing (e.g. tight fit, loop lashing) and/or by frictional securing (e.g. tie-down lashing).

Figure 4

Figure 4
Figure 5

Figure 5


For cargo securing, see the chapter entitled Pipes in the GDV Cargo Securing Manual.

For further information see also the chapters entitled

"Basic physical principles of cargo securing",
"Road vehicles, selection, equipping and loading capacity",
"Cargo securing materials".

Ship:

The following principles apply:

Select stowage spaces in accordance with the sensitivity of the cargo and anticipated accelerations
Where possible, load cargo closely against parts of the vessel or other cargo having sufficient loading capacity, but ...
... stow and secure in such a way that no excessive loads are applied to the hull or other parts of the vessel
Where possible, friction-enhancing materials should be laid beneath the cargo and between layers
Fill in any gaps between individual items of cargo
Protect cargo from chafing, scratching and similar mechanical damage
Protect cargo from harm caused by lashings and other securing materials
Heavy goods in particular, such as steel products, should where possible be stowed without gaps in a level layer from ship's side to ship's side


Where possible, pipes should not be stowed with their axis athwartships, unless they can be stowed in combination with upright layers and cargoes with a high loading capacity (buffer stow). Securing transversely stowed pipes is otherwise extremely difficult.

Figure 6

Figure 6


When transporting large pipes or very long cargoes, any unusable or inaccessible areas of the holds, especially in the fore and aft hatches must be filled with shores or the like.

Figure 7

Figure 7


Railroad:

Pipes must be transported in freight cars having a headboard and side walls (stanchions) with sufficient strength and loading capacity. Friction-enhancing material should also be placed under the load and between layers. Gaps between the load and the headboard and side walls should be avoided. Gaps in the longitudinal direction in particular may result in slippage of the pipes on switching impact. If gaps in the load are unavoidable for reasons of proper load distribution, the load must be secured in accordance with anticipated accelerations by direct securing (e.g. tight fit, loop lashing) and/or by frictional securing (e.g. tie-down lashing).

Figure 8

Figure 8



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Risk factors and loss prevention

RF Temperature

Pipes do not have any particular ambient temperature requirements for transportation and storage. It should however be noted that the temperature of the pipes determines whether the cargo sweats.


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RF Humidity/Moisture

Pipes require particular humidity/moisture and possibly ventilation conditions (SC IV) (storage climate conditions).

Designation Humidity/water content Source
Relative humidity <40 - 50% [1]


Steel is a cargo which is at risk of corrosion. Corrosion losses are in particular caused by

Seawater and seasalt aerosols,
during maritime transport due to leaky containers or hatches
during storage at sea ports near water
Rain water,
when containers are damaged
uncovered railroad freight cars and trucks
incorrect storage in the open
use of unsuitable tarpaulins
exposed loading in wet weather conditions
Condensation water,
on the means of transport
on the cargo/load
within the packaging
Accompanying chemical cargo,
Residues of chemicals from previous cargoes, possibly combined with moisture,
Hygroscopic accompanying cargo (e.g. fresh lumber) and
Relative humidities > 40%.



Steel corrosion begins at a relative humidity of 40% and rapidly accelerates at relative humidities > 60%:

Increase in corrosion

Figure 9


A distinction may be drawn between various Types of corrosion .

There are two main causes of corrosion:

Pure oxidation and
electrochemical decomposition of the metal due to the presence of an electrolyte (e.g. salts, acids, bases).


Pure oxidation means combination of the ferrous metal with atmospheric oxygen. Oxidation is assisted by electrochemical (electrolytic) processes. The extent of electrolytic decomposition is determined by the conductivity of the electrolyte present. For example, salt water is more conductive than fresh water and therefore has a greater corrosive effect. The effect of sulfurous acid is even more extreme.

If corrosion damage is suspected, testing is performed using the silver nitrate method, to find out whether chloride solutions or fresh water are the cause. When determining the origin of the sea salt on the cargo surface (corrosion resulting from contact with seawater or spray deposition by the hold/container air), the damaged surface is assessed with a magnifying glass (30x magnification): cubic sodium chloride (NaCl) crystals of an edge length of approx. 1/5 mm indicate contact with seawater. In the case of spray deposition, no crystal structures may be observed, since the crystals are too small (1/100 mm).

Thin-walled pipes of a relatively small diameter are in particular highly sensitive to corrosion, for which reason such pipes are frequently provided with a protective coating.

In the case of pipes made from hot-rolled steel, it is usual to store them in the open and to transport them without protection, such that no protection is provided against rain etc.. Such pipes therefore generally exhibit a layer of surface rust (rust film). Since the rust is removed from the steel (by pickling) prior to further processing, the quality of the steel is not impaired. Hot-rolled material must also be protected from chloride solutions (e.g. seawater or fertilizers) as pickling cannot remove uneven local corrosion or pitting corrosion. Especially in the case of damage by salt water, the pipes should be rinsed off with fresh water as soon as possible after arrival with the receiver and then pickled because significant delay prior to pickling may have the above-stated consequences. For reasons of quality maintenance, the aim should always be to store, handle and transport the sheets in the dry.

Surface coated pipes (e.g. galvanized pipes) are more sensitive to corrosion than those made from hot-rolled steel, such that the former should additionally be packed in fiber-reinforced packing or plastic-coated kraft paper (montan paper) and plastic films. It is therefore important to keep moisture away at all times; unprotected storage in the open or unprotected cargo handling in wet weather should be avoided.

Figure 10

Figure 10



Moisture may, for example, give rise to a white bloom on the zinc coating. If rain or condensation water penetrates between stacked galvanized pipes, the thin, protective zinc oxide layer does not form, but rather a thicker layer of pure zinc oxide. At the contact points between the pipes, this layer has the appearance of scurf.


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RF Ventilation

Pipes require particular humidity/moisture and possibly ventilation conditions (SC IV) (storage climate conditions).

Steel corrosion accelerates rapidly at relative humidity > 60%. If possible, relative humidity should be reduced to below 60% by appropriate ventilation measures.

However, the following should be noted:
  1. Steel exhibits a lower temperature than the external temperature anticipated during transit:

    If the temperature of the ambient air outside the ship rises, this has only a minimal effect on the temperature of the cargo. Ventilation with "warm" external air may result in cargo sweat on the "cold" steel, if the temperature of the latter is below the dew point of the ambient air. In such a case, ventilation may encourage corrosion.

  2. The steel is warmer than the external temperatures anticipated in transit:

    Ventilation may be performed without any risk of cargo sweat formation. However, cooling of the ship's sides may cause their temperature to drop below the dew point of the hold air, resulting in ship sweat inside the hold. In this case, the temperature of the hold air should be adjusted by ventilation to match that of the external air.

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RF Biotic activity

This risk factor has no significant influence on the transport of this product.


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RF Gases

Sulfur dioxides (exhaust gases from e.g. cargo handling equipment) have an extremely corrosion-promoting action on steel. It is therefore essential to prevent any contact with sulfur and its gases. Holds should accordingly be cleaned prior to loading.


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RF Self-heating / Spontaneous combustion

This risk factor has no significant influence on the transport of this product.


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RF Odor

This risk factor has no significant influence on the transport of this product.


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RF Contamination

Active behavior Steel pipes are frequently coated with grease, bitumen or similar substances to protect them from corrosion and as a result may contaminate other products.
Passive behavior Dust from coal, ores, salts and especially fertilizers and other bulk materials has a corrosive effect. For this reason, holds/containers have accordingly to be washed clean, to remove any residues from previous cargoes. When washing out ship holds with seawater, it must be borne in mind that seawater also contains salts which would encourage corrosion later in the voyage. It is therefore best to use fresh water for cleaning purposes.

The product should also be protected from acids, aggressive gases (sulfur dioxide) and readily decomposing chemicals, as these also accelerate corrosion.



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RF Mechanical influences

In order to avoid damage to pipes or their packaging by mechanical stresses, it is essential that stowing, cushioning, bracing, lashing and securing on the means of transport are performed carefully and in accordance with instructions. Suitable slinging and cargo handling equipment and lifting gear must be selected and used on the basis of the cargo's weight and slinging points.

Damage due to mechanical stresses in particular take the form of notching and bruising of the pipe ends and of buckling of the entire pipe. Excessive damage to the pipe ends may entail subsequent reprocessing of the pipes. Chamfers (beveled edges) are provided with plastic or metal caps to protect them from damage. Care must be taken to ensure that all these caps are present.

Figure 11

Figure 11


With bundled pipes, care must be taken to ensure that strapping is very tight. If the strapping is damaged or broken, the bundle loosens, as a result of which the tubes may move and damage each other. Strapping may also cause chafing on the surfaces and edges, so damaging them.

Careless use of handling equipment may result in damage (damage to protective coating). Thin pipes in particular must not be in the least bent as they are then unusable for their intended use. Relatively large diameter pipes may, under certain circumstances, be restored, for example by straightening or cutting off the bruised ends.


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RF Toxicity / Hazards to health

This risk factor has no significant influence on the transport of this product.


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RF Shrinkage / Shortage / Theft

This risk factor has no significant influence on the transport of this product.


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RF Insect infestation

This risk factor has no significant influence on the transport of this product.


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