The outer protective layer 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 surface polarization process that significantly enhances its adhesive compatibility with polyurethane. This innovative approach ensures superior adhesion performance, offering unmatched durability and unparalleled efficiency in thermal insulation applications, making it the prime choice for robust, long-lasting underground steam piping solutions.
| 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 pipe, spiral welded pipe, and straight seam welded pipe. Before thermal insulation, our pipes undergo rigorous mechanical rust removal to ensure a quality standard that meets or exceeds GB/T8923.1 Sa level 2.5. This guarantees unparalleled reliability and durability, making our pipes the gold standard in the industry.
2. Slepipe: Engineered with an exclusive blend of modified flame retardant and anti-static polyethylene resin, processed using state-of-the-art single screw extrusion technology. This results in pipes with exceptional impact resistance, superior isolation properties, and formidable corrosion resistance, perfectly suited for the most demanding applications.
3. Polyurethane Insulation Layer: We utilize cutting-edge, modified flame retardant polyurethane foam, injected under high pressure to fill the gap between the casing and the working steel pipe. This process ensures a superior insulation effect, characterized by exceptionally low thermal conductivity, high compression strength, minimal water absorption, and an impressive closure rate, guaranteeing optimal thermal performance.
1. Eliminates the need for additional support, significantly reduces heat loss, and completely eradicates the 'support thermal bridge' phenomenon, greatly enhancing energy efficiency.
2. Offers remarkable strength and excellent toughness, combined with ease of welding and convenient construction. This ensures seamless integration into any project, providing both efficiency and durability.
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 unparalleled versatility and reliability.
4. Ensures straightforward connection through flange or quick joint connections, simplifying the installation process and significantly reducing labor costs.
5. Boasts an impressive service life, enduring challenging environments with temperatures ranging from -20ºC to 120ºC for over 30 years, thereby ensuring long-term performance and reliability.
Discover a diverse array of connection methods meticulously designed to amplify the efficiency and reliability of your operational processes.
| Flange connection |
Flexible socket connection |
Experience a comprehensive welding joint demonstration that ensures seamless integration and delivers robust, long-lasting 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.
Shandong Donghong Pipe Industry Co., Ltd. (stock code: 603856), or Donghong Co., Ltd., is proudly based in the historically rich city of Qufu, China, the birthplace of Confucius. As a trailblazer in the engineering pipeline sector, we stand out as a premier manufacturer, comprehensive service provider, and general contractor. Our expertise spans four pivotal categories of specialized and tailored pipeline solutions: rainwater and sewage diversion, municipal services, industrial and mining sectors, and key national engineering projects. At Donghong Co., Ltd., we are committed to creating a vibrant industrial ecosystem that integrates design institutes, financial institutions, port logistics, construction firms, and a network of upstream and downstream enterprises. Our visionary approach is set on transforming the global pipeline industry. Our mission is to lead with intelligent pipeline solutions that not only elevate the quality of life but also guarantee the long-lasting safety of pipeline transportation.
Donghong Co., Ltd. boasts a dynamic team of over 200 R&D experts and holds an impressive collection of over 100 patents. Our spirit of innovation is powered by national technology platforms, including our enterprise technology center, CNAS laboratory, academician expert workstation, and post-doctoral workstation. We are at the forefront of digitalizing, informatizing, and intelligentizing pipeline engineering, propelling the industry forward and establishing new benchmarks of excellence.
In November 2017, Donghong Co., Ltd. marked a monumental milestone by becoming the first company in China's engineered composite piping systems sector to be listed on the main board of Shanghai.
Outstanding Technical Research and Development Capabilities
Our cutting-edge national CNAS laboratory is equipped with the latest testing technologies, facilitating the innovation of new products, materials, and connection types. This stringent testing ensures that our products maintain consistent stability and reliability, reflecting our unwavering dedication 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. With a meticulous approach to packaging and shipping, we safeguard the integrity and quality of our Pre-insulated pipes, making them ready for immediate installation upon arrival, providing you with the ultimate convenience and peace of mind.
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, thus guaranteeing the highest quality and reliability.
2. What kinds of services do you offer?
As a manufacturing powerhouse, we offer an extensive range of pipe products, fittings, packaging, and seamless shipping solutions. In addition, our consultancy services provide expert project consulting, innovative pipe system solutions, and detailed design recommendations. Furthermore, as an engineering-focused enterprise, we excel in pipeline contracting, repair services, and free maintenance guidance, ensuring comprehensive support for all your requirements.
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.
Audited Supplier 
){kind=link}
){kind=link}