Introduction
Polyethylene pipes and fittings are light in weight and easy to handle compared to many other materials. They have considerable resilience, flexibility and resistance to impact. However PE pipes and fittings can be scored by sharp edges and can be distorted under load, particularly at higher temperatures. Therefore, in general, PE pipes and fittings should not be dropped, indented, crushed or impacted and should not be subjected to rough handling during loading and unloading operations.
General
Pipes and fittings must not be stored or transported adjacent to heat sources, such as engine exhausts, boilers, naked flames or hot water or steam lines. While PE is very resistant to low temperature, as the temperatures drops below 0°C the impact resistance will slowly reduce, and therefore more care should be taken to avoid damage by impact.
Care should be taken in handling pipes and fittings in wet and frosty conditions as they may become slippery.
As with all pipe materials, contact with oils, petrol, solvents or chemicals that might have an adverse effect on future performance should be avoided.
Typically, scores or scratches to a depth of more than 10% of the wall thickness should be avoided for pressure applications.
Polyethylene is combustible, but there are no restrictions on the type of fire extinguisher which can be used.
Generally, only webbing slings should be used to lift PE pipes by crane. Vacuum lifting may be used, but chains, wire ropes and hooks should be avoided.
In the storage and issuing of pipe and fittings the principle of "first in, first out" should preferably be observed.
Lifting, handling, storage and transport of straight lengths
Lifting of individual pipes or packs up to 6 m in length can be performed by a fork lift. To prevent drooping of long packs or individual pipes and subsequent scuffing of pipe ends, two lifting points or spreader bars should be used for pipe s or pipe packs exceeding 6 meters in length.
Appropriate personnel exclusion zones should apply when lifting PE pipes in order to avoid injury if the pipe slips.
Straight pipe lengths stacked for storage or transport should be continuously and evenly supported to minimise distortion.
Pipes with end treatments such as belling, forming, flanging or pre-assembled fittings should be stacked so that the ends are free from loading; if necessary they should be protected from damage. Pipes cut and squared for butt fusion should be given special attention to ensure that they are always handled, particularly in transit, in a manner that keeps the pipe ends free from damage.
If different SDR’s of pipe are kept in the same stacks then the lowest SDR (thickest wall) should always be at the bottom. Pipes may be nested inside each other for transport or storage provided distortion does not occur. When being transported, pipes should not be restrained in a manner likely to result in damage to them.
Lifting, handling, storage and transport of coils
Larger diameter coiled polyethylene pipes, for example those of diameters equal to or greater than 63mm can be very heavy and pose particular handling and storage risks. The consequences of coils falling or slipping should always be considered as serious injury can occur. This is particularly the case for coils stored in a vertical or near vertical position. For unloading heavier coils, delivery sites should be equippedwith cranes or forklifts or crane-trucks should be used
When lifting coils, slings must be placed around the entire coil. If coils are lifted by a fork truck, contact points must be protected and the lifting must be performed on the entire coil. Fork tines should not be inserted between windings in a coil.
Coiled pipe can be stored and transported by being laid flat on a continuous surface such as pallets but stored only to such a height that the bottom convolutions do not become distorted. Pipe coils can also be stored and transported in a near vertical position. Care must be exercised to ensure the support against which the coils are leant are strong enough to withstand the load. Care should also be taken to ensure the external loops of the vertically supported coil are not damaged or flattened in transport.
When releasing coils and uncoiling PE pipe, it must be remembered that the coil is under tension and must be released in a controlled manner. The end of the coil should be restrained at all times, then the straps released steadily, one at a time. If the coil has bands at different layers of the coil, then they should be released sequentially starting from the outer layers. The amount of energy locked up in the coil will depend on the size of pipe, the class of the pipe, and the size of the coil. The amount of energy can be substantial and cause significant injury or damage if released in an uncontrolled manner. The person releasing the restraining straps should stand at a safe position at the side of the coil.
Lifting, handling, storage and transport of compression, mechanical and fabricated fittings
Compression, mechanical and fabricated fittings should be stored, handled and transported in a manner that does not cause undue scoring to the body of the fitting or damage to any sealing surfaces. Wherever possible, fittings should be retained in their original packaging until ready for use. In order to eliminate the risk of damage to the fitting or injury to personnel, larger fittings may be strapped to pallets to prevent their moving or falling.
Lifting, handling, storage and transport of compression, mechanical and electrofusion fittings
Electrofusion fittings are usually stored and transported in cartons on pallets. They should be handled using standard safe working practices. Fittings must be stored under cover in dry conditions and kept in their packaging, which is intended to keep the weld surfaces clean, until ready for use.