1. The carrier pipe of the steel insulated pipe is seamless steel pipe for fluid conveyance, to GB 8163—99 or GB 3087; other standards may be used at the customer's request or according to supply conditions.

　　2. Insulation layer: Hydrophobic composite silicate pipe shells or XN-3 aluminum silicate (moisture-proof ceramic) insulation shells are used; other insulation materials may also be selected per customer requirements. The insulation material is bound to the carrier pipe in a staggered double-layer, offset-peak arrangement to form an integral layer, reducing heat loss, avoiding surface friction with the steel casing, and extending the service life of the insulation. Thickness is determined by the medium temperature.

　　Main technical indicators of composite silicate. Note: This product is non-toxic, harmless, and non-polluting. It is composed of a steel pipe conveying the medium, an anti-corrosion outer steel jacket, and ultra-fine glass wool filled between the steel pipe and the outer steel jacket. It can also be composed of graphite, calcium silicate tile shells, and filled PU foam composites.

　　Steel-in-steel insulated pipe is a new fully enclosed burial technology that is waterproof, leak-proof, impermeable, and pressure-resistant—a major breakthrough in applying direct-buried laying in areas with a high groundwater table. The primary issue for the protective pipe of a direct-buried pipeline is reliable, tight waterproofing, together with good mechanical strength. Because of its high mechanical strength and welded connections, a steel casing offers highly reliable waterproof sealing; in addition, its high-temperature resistance is unmatched by other outer jackets. In areas with a high groundwater table, to ensure that groundwater does not affect the normal operation of direct-buried steam pipelines, a strong, sealed steel outer shell is the preferred protective jacket.

　　1. Waterproof and moisture-proof

　　2. Resistant to high temperature and high pressure; suitable for medium temperature of 350°C and pressure of 2.5 MPa

　　3. Low heat consumption; insulation performance superior to any conventional insulation method

　　4. Strong anti-corrosion capability; the coating is high in strength and not easily damaged

　　5. Long service life, up to 30–50 years

　　The primary issue for the protective pipe of a direct-buried pipeline is the reliability of tight waterproofing. In addition, it must have good mechanical strength. Steel-in-steel insulated pipe uses welded connections due to its high strength, so the reliability of waterproof sealing is very high. In addition, its high-temperature resistance cannot be matched by other outer jackets.

　　Insulated steel pipe uses two coats of inorganic zinc-rich primer as the anti-corrosion coating. Pipe ends are sealed with polyethylene film, three-layer PE, or cold-applied tape to prevent moisture from entering before installation or water from entering during construction. The insulation is wrapped in multiple staggered layers, effectively reducing heat loss, while jacket-surface measures prevent cold bridges and thereby ensure temperature control of the jacket anti-corrosion coating. Wrapping the insulation with multiple layers of aluminum-foil reflective material effectively reduces heat loss and makes the steam pipeline more economical.

　　That concludes the above introduction by Jinan insulated pipe to the performance features of steel-in-steel insulated pipe. We hope it is helpful. Follow us for more industry news. https://www.sdhpgy.com