Our state-of-the-art outer protective layer is meticulously engineered using high-strength, high-toughness polyethylene material. Leveraging the groundbreaking polyethylene modification technology developed by Shandong Donghong Pipe Industry Co., Ltd., this layer undergoes an advanced surface polarization process. This technology significantly enhances its adhesive compatibility with polyurethane, ensuring superior adhesion performance. The result is unmatched durability and unparalleled efficiency in thermal insulation applications, setting a new industry standard.
| 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 seamless steel pipe, spiral welded pipe, and straight seam welded pipe. Before thermal insulation, each pipe undergoes an intensive mechanical rust removal process to ensure a pristine quality standard, meeting or exceeding GB/T8923.1 Sa level 2.5.
2. Slepipe: Innovatively engineered with a specialized modified flame retardant and anti-static polyethylene resin, our Slepipe is processed using a state-of-the-art single screw extrusion machine. This grants the pipe exceptional impact resistance, superior isolation properties, and formidable corrosion resistance, making it a standout in its field.
3. Polyurethane Insulation Layer: Utilizing modified flame retardant polyurethane foam injected under high pressure, we fill the gap between the casing and the working steel pipe. This method ensures an extraordinary insulation effect, marked by low thermal conductivity, high compression strength, minimal water absorption, and an elevated closure rate, positioning it in a league of its own.
1. Efficiently eliminates the need for support, significantly reduces heat loss, and completely eradicates the phenomenon of the 'support thermal bridge,' ensuring optimal performance.
2. Provides exceptional strength and remarkable toughness. Thanks to its easy welding and convenient construction, it ensures efficient and reliable installations.
3. Boasts low thermal conductivity along with robust waterproof and corrosion resistance. Perfectly suited for direct burial in the ground or underwater applications, it stands resilient in diverse environments.
4. Facilitates easy and secure connections through flange or quick joint methods, ensuring a seamless and efficient setup.
5. Offers an impressive service life, designed to endure and perform in environments ranging from -20ºC to 120ºC for over 30 years, showcasing its durability and reliability.
Explore Various Connection Methods
| Flange connection |
Flexible socket connection |
Comprehensive Welding Joint Demonstration
Insulation steel pipes are an essential component in the insulation projects of liquid and gas transmission pipes across diverse sectors. Whether it's petroleum, chemical industries, central heating systems, heating networks, central air-conditioning ventilation pipes, or municipal engineering, our high-temperature prefabricated direct-buried thermal insulation steel pipes excel as the premier choice. They provide outstanding thermal insulation performance, unmatched safety and reliability, and significantly lower construction costs, making them the ultimate solution for all your insulation needs.
Shandong Donghong Pipe Industry Co., Ltd. (referred to as: Donghong Co., Ltd., stock code: 603856) is headquartered in Qufu, China, the revered hometown of Confucius. We stand as a premier engineering pipeline manufacturer, comprehensive pipeline engineering service provider, and trusted general contractor. Our core business encompasses four primary categories of functional and customized pipeline solutions: specialized pipelines for rainwater and sewage diversion, municipal areas, industrial and mining zones, and national key engineering projects. By fostering an industrial ecosystem that integrates design institutes, financial institutions, port logistics, construction units, and both upstream and downstream enterprises, Donghong Co., Ltd. is dedicated to transforming the global pipeline landscape. Our mission is to lead with intelligent pipelines that enhance human life and ensure the perpetual safety of pipeline transportation.
Donghong boasts a team of over 200 R&D professionals and holds more than 100 patents. Our innovation is anchored by national technology platforms such as the enterprise technology center, CNAS laboratory, academician expert workstation, and post-doctoral workstation. We are at the forefront of researching and advancing the digitalization, informatization, and intelligentization of pipeline engineering, steering the industry's evolution and setting new benchmarks of excellence.
In November 2017, Donghong achieved a significant milestone by being listed on the main board of Shanghai, marking a historic 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, facilitating the development of new products, materials, and connection types. This rigorous testing ensures our product quality remains consistently stable and reliable, maintaining our unwavering commitment to excellence.
Donghong has established strategic partnerships with over five leading 5A-level logistics companies, boasting extensive years of transportation expertise. By integrating automobile transport, railway logistics, and port and shipping solutions, we ensure unparalleled service regardless of extreme heat, cold, or challenging remote locations. Our robust and comprehensive transportation strategy guarantees that every shipment reaches the customer site with utmost speed and efficiency.
1. Does your product meet international standards?
Our products proudly meet and exceed international standards, having achieved CE, BV, ISO, and WAR certifications. Rest assured, all figures surpass the required benchmarks. Should you have a specific national standard in mind, we are more than happy to verify or conduct tests accordingly.
2. What kinds of services do you offer?
As an end-to-end manufacturing powerhouse, we offer a vast array of pipe products, fittings, packaging, and shipping services. Our consultancy division excels in project consulting, innovative pipe system solutions, and expert design advice. Moreover, our engineering expertise encompasses comprehensive pipeline contracting, repair services, and complimentary maintenance guidance.
3. Do you support OEM/ODM services?
Absolutely, we specialize in OEM/ODM services tailored to your needs, including material choice, specifications, logos, packaging, and connection methods. Our dedicated team is adept at crafting bespoke solutions for your unique projects, as demonstrated by our extensive portfolio of successful customizations.
4. What are your terms of payment?
We accommodate flexible payment terms, accepting T/T or L/C at sight for your convenience.
5. How can you guarantee the quality of your goods?
We invite all customers to visit our facilities and witness the quality of our goods firsthand. Additionally, we offer rigorous pre-order testing based on customer requirements. To ensure your satisfaction, we can also provide samples for thorough examination before commencing bulk production.
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