The outer protective layer of our Underground pre-insulated pipe with thermal insulation jacketing for industrial applications is meticulously crafted from high-strength, high-toughness polyethylene material. Utilizing Shandong Donghong Pipe Industry Co., Ltd.'s revolutionary polyethylene modification technology, this layer undergoes a state-of-the-art surface polarization process that significantly enhances its adhesive compatibility with polyurethane. This innovative approach ensures superior adhesion performance, providing unmatched durability and efficiency in all thermal insulation applications, making it an ideal choice for demanding industrial environments.
| Working Steel Pipe Diameter mm |
Outer Sheath Diameter mm |
Minimum thickness of outer sheath mm |
Insulation layer thickness mm |
| 426 |
494-554 |
4.0 |
30-60 |
| 478 |
547-607 |
4.5 |
30-60 |
| 529 |
598-658 |
4.5 |
30-60 |
| 630 |
700-760 |
5.0 |
30-60 |
| 720 |
790-850 |
5.0 |
30-60 |
| 820 |
891-951 |
5.5 |
30-60 |
| 920 |
992-1052 |
6.0 |
30-60 |
| 1020 |
1093-1153 |
6.5 |
30-60 |
| 1120 |
1194-1254 |
7.0 |
30-60 |
| 1220 |
1316-1436 |
8.0 |
40-100 |
| 1420 |
1538-1678 |
9.0 |
50-120 |
| 1620 |
1760-1880 |
10.0 |
60-120 |
| 1820 |
1960-2080 |
10.0 |
60-120 |
| Note: can be customized as customer's needs. |
1. Working Steel Pipe: Meticulously crafted from premium seamless steel, spiral welded, and straight seam welded pipes. Before receiving thermal insulation, each pipe undergoes a stringent mechanical rust removal process. This ensures the quality standard meets or exceeds GB/T8923.1 Sa level 2.5, delivering reliability and unparalleled durability.
2. Slepipe: Engineered with a proprietary blend of advanced flame retardant and anti-static polyethylene resin, processed using cutting-edge single screw extrusion technology. This innovation grants our pipes exceptional impact resistance, superior isolation properties, and formidable corrosion resistance, making them ideal for the most demanding applications.
3. Polyurethane Insulation Layer: Employing cutting-edge modified flame retardant polyurethane foam, injected under high pressure into the gap between the casing and the working steel pipe. This process creates a superior insulation effect, characterized by ultra-low thermal conductivity, high compression strength, minimal water absorption, and an impressive closure rate, ensuring optimal thermal performance.
1. Eliminates the need for additional support, significantly reducing heat loss and completely eradicating the 'support thermal bridge' phenomenon. This enhances overall energy efficiency.
2. Offers remarkable strength and excellent toughness, combined with ease of welding and convenient construction. This ensures seamless integration into any project.
3. Exhibits exceptionally low thermal conductivity along with robust waterproof and corrosion resistance properties. Ideal for direct burial in the ground or underwater applications, providing unmatched versatility and reliability.
4. Ensures straightforward connection through flange or quick joint connections, simplifying the installation process and reducing labor costs.
5. Boasts an impressive service life, operating effectively in challenging environments with temperatures ranging from -20ºC to 120ºC. Designed to endure over 30 years, ensuring long-term performance and reliability.
Discover an array of advanced connection methods specifically designed to elevate the efficiency and reliability of your industrial operations.
| Flange connection |
Flexible socket connection |
Experience a comprehensive welding joint demonstration tailored for seamless integration and unparalleled robustness, ensuring optimal performance.
Insulation steel pipes are indispensable in liquid and gas transmission pipe insulation projects across various sectors such as petroleum, chemical industries, central heating systems, heating networks, central air-conditioning ventilation pipes, and municipal engineering. Our high-temperature prefabricated direct-buried thermal insulation steel pipe stands out as a premier choice, offering exceptional thermal insulation performance, unparalleled safety and reliability, and notably reduced construction costs. Specifically designed to excel in the most demanding conditions, these pipes ensure longevity and efficiency, making them an invaluable asset for industrial and municipal applications alike. By choosing our solution, you are making a wise investment in cutting-edge technology, superior engineering, and sustainable infrastructure. Choose Shandong Donghong Pipe Industry Co., Ltd. for your underground pre-insulated pipe needs and experience the ultimate in durability and innovation.
Shandong Donghong Pipe Industry Co., Ltd. (referred to as: Donghong Co., Ltd., stock code: 603856) is headquartered in Qufu, China, the historic and culturally rich hometown of Confucius. We are a distinguished leader in the engineering pipeline sector, excelling as a manufacturer, comprehensive service provider, and general contractor. Our core business encompasses four primary categories of specialized and customized pipeline solutions: rainwater and sewage diversion, municipal projects, industrial and mining operations, and pivotal national engineering initiatives. By cultivating a robust industrial ecosystem that integrates design institutes, financial institutions, port logistics, construction firms, and both upstream and downstream enterprises, Donghong Co., Ltd. is on a mission to revolutionize the global pipeline industry. Our vision is to spearhead innovation with intelligent pipeline solutions that elevate the quality of life and ensure the enduring safety of pipeline transportation.
Donghong proudly boasts a team of over 200 R&D experts and an impressive portfolio of more than 100 patents. Our relentless innovation is fueled by national technology platforms, including our enterprise technology center, CNAS laboratory, academician expert workstation, and post-doctoral workstation. We are at the forefront of digitalization, informatization, and intelligentization in pipeline engineering, propelling the industry forward and setting new benchmarks of excellence.
In November 2017, Donghong marked a historic milestone by being listed on the main board of Shanghai, a groundbreaking first for engineered composite piping systems in China.
Outstanding Technical Research and Development Capabilities
Our national CNAS laboratory is equipped with cutting-edge testing equipment, driving the development of new products, materials, and connection types. This rigorous testing ensures that our product quality remains consistently stable and reliable, underscoring our unwavering commitment to excellence.
Donghong has established strategic partnerships with over five elite 5A-level logistics companies, boasting extensive expertise in transportation. Utilizing a dynamic blend of automobile, railway, port, and shipping logistics, we ensure unparalleled service, regardless of extreme temperatures or challenging locations. Our robust transportation strategy guarantees timely delivery to your site, maintaining the highest standards of efficiency and reliability.
1. Does your product meet international standards?
Our products have not only successfully passed CE, BV, ISO, and WAR certifications but have also exceeded all required standards. Specify the national standard you need, and we will either verify or test it to ensure compliance, guaranteeing the highest quality and reliability.
2. What kinds of services do you offer?
As a proud manufacturing factory, we provide an expansive range of pipe products, fittings, packaging, and shipping solutions. In our role as a consultancy, we offer expert project consulting, innovative pipe system solutions, and detailed design recommendations. Additionally, as an engineering-focused enterprise, we excel in pipeline contracting, repair services, and free maintenance guidance, ensuring comprehensive support for all your needs.
3. Do you support OEM/ODM services?
Absolutely, we offer extensive customization options in materials, specifications, logos, packaging, and connection methods. Our expert team is proficient in delivering tailored solutions for your unique projects, backed by numerous successful cases that highlight our exceptional service.
4. What are your terms of payment?
We accept T/T (Telegraphic Transfer) or L/C (Letter of Credit) at sight, providing flexibility and convenience in our payment options.
5. How can you guarantee the quality of your goods?
We warmly invite all customers to visit our company and inspect our goods firsthand. We are also capable of conducting rigorous tests as per your request before the order. Additionally, we can send samples before bulk production for your testing and approval, ensuring the highest quality standards are met for your satisfaction.
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