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, providing unmatched durability and efficiency in thermal insulation applications.
| 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: Crafted from seamless steel pipe, spiral welded pipe, and straight seam welded pipe. Prior to thermal insulation, our pipes undergo mechanical rust removal to achieve a quality standard not lower than GB/T8923.1 Sa level 2.5.
2. Slepipe: Engineered with a special modified flame retardant and anti-static polyethylene resin, processed by a single screw extrusion machine. This lends our pipes exceptional impact resistance, superior isolation, and formidable corrosion resistance.
3. Polyurethane Insulation Layer: We utilize modified flame retardant polyurethane foam injected under high pressure to fill the gap between the casing and the working steel pipe. This creates an unparalleled insulation effect, characterized by low thermal conductivity, high compression strength, minimal water absorption, and an elevated closure rate.
1. Eliminates the need for support, reduces heat loss, and completely eradicates the phenomenon of 'support thermal bridge'.
2. Offers high strength and excellent toughness, with easy welding and convenient construction.
3. Exhibits low thermal conductivity and robust waterproof and corrosion resistance, making it suitable for direct burial in the ground or underwater.
4. Ensures easy connection through flange or quick joint connections.
5. Boasts a long service life, enduring in environments from -20ºC to 120ºC for over 30 years.
Different connection methods
| Flange connection |
Flexible socket connection |
Welding joint demonstration
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.
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 more than 5 5A-level logistics companies, and we have many years of transportation experience. Combining automobile transportation, railway transportation, port and shipping logistics, etc., no matter the heat or cold, no matter the area is remote or harsh, we can provide you with the best service. We have a comprehensive transportation strategy to ensure that every shipment is delivered to the customer site as soon as possible.
1. Does your product meet international standards?
Our products have successfully passed CE, BV, ISO, and WAR certificates, with all figures exceeding the required standards. Feel free to specify the national standard you need, and we'll verify or test it accordingly.
2. What kinds of services do you offer?
As a manufacturing factory, we provide a comprehensive range of pipe products, fittings, packaging, and shipping. As a consultancy, we offer project consulting advice, pipe system solutions, and design recommendations. Additionally, as an engineering-focused enterprise, we provide pipeline contracting, repair services, and complimentary maintenance guidance.
3. Do you support OEM/ODM services?
Yes, we offer customization in materials, specifications, logos, packaging, connection methods, and more. Our expert team can also provide tailored solutions for your specific projects, with numerous successful cases showcasing our service.
4. What are your terms of payment?
We accept T/T or L/C at sight.
5. How can you guarantee the quality of your goods?
We warmly welcome all customers to visit our company and inspect our goods firsthand. We can also conduct stringent tests as requested by customers before the order. Additionally, we can dispatch samples before bulk production for customer testing and qualification.
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