After insulated pipes arrive at the construction site, they are often not installed immediately and may need to be stored for several days or even longer. Improper storage during this period can lead to problems such as aging of the outer protective pipe, dampness of the foam, and water ingress into the pipe ends. These issues may only be discovered during installation, at which point it may be too late. The following storage requirements are worth noting for on-site management personnel:
Site selection is the first step. The storage site should be flat, free of hard debris such as gravel, and have sufficient load-bearing capacity to prevent collapse or tipping after stacking. There should be no standing water on the site; drainage ditches are recommended. The storage area should be far away from fire and heat sources, generally at least 2 meters away. Fire-fighting facilities should also be available on-site.
The stacking method is important. Insulated pipes cannot be placed directly on the ground. Pipe supports should be provided at the stacking site, with the lower surface of the outer protective pipe at least 150 mm above the ground. The width of the pipe supports should be greater than 150 mm, and the height should be greater than 100 mm. Similar types of pipes should be stored together; different types and batches should not be mixed. The stacking height should not exceed 2 meters, and even short-term stacking should not exceed 1.5 meters. Nameplates should be displayed at the storage area, specifying pipe diameter, wall thickness, and insulation layer thickness.
Waterproofing and sun protection are crucial. Although polyurethane foam itself has some waterproof properties, prolonged contact with rainwater will cause the insulation material to absorb water, affecting its insulation performance. Polyethylene outer protective pipes will also age faster under prolonged exposure to sunlight. Therefore, when storing outdoors, tarpaulins should be used to cover the pipes to avoid direct sunlight and rain. The pipe ends should also be sealed to prevent rainwater from seeping into the insulation layer.
Storage time should not be too long. Different standards vary slightly regarding the outdoor storage period; some require no more than 6 months, while others recommend no more than 3 months. Generally, the shorter the outdoor storage time, the better. Finished insulation pipes should not be stored outdoors for more than one month. If storage time is longer, they should be stored in a sheltered warehouse. When storing outdoors for longer than a certain period, even stronger covering and pipe end sealing are necessary.
Handling and hoisting should be done with care. When hoisting insulated pipes, use hoisting slings wider than 50 mm; direct hoisting with steel wire ropes is strictly prohibited. Handle with care during loading and unloading to avoid bumps and damage to the outer protective pipe.
On-site storage of insulated pipes may seem like a minor matter, but damage caused by improper storage is often irreversible. A level site, raised platforms for moisture protection, covering for sun protection, pipe end sealing, controlling height and time, and standardized hoisting-only by doing these things properly can you ensure peace of mind after the pipes are buried.