26 Inch Thermal Insulation Pipes

Product Specification

Large-Caliber Anti-Corrosion And Thermal Insulation Steel Pipe For Water Supply Pipe Heating

Insulation steel pipe refers to a steel pipe that has been processed by heat preservation technology and under the action of different working environments and external media to ensure that the internal temperature and surface temperature of the working steel pipe meet or meet the requirements for use.

1. Steel sleeve steel composite insulation steel pipe
According to different sliding methods, the insulation structure of steel sleeve steel composite insulation steel pipe can be divided into two categories: 1. Internal sliding type: the insulation structure consists of working steel pipe, aluminum silicate, drag reduction layer, microporous calcium silicate, heat insulation layer, and stainless steel It is composed of fastening steel strip, aluminum foil reflective layer, polyurethane insulation layer, outer steel pipe, and outer anti-corrosion layer. The inner sliding type thermal insulation steel pipe is composed of a steel pipe for conveying medium + composite silicate or microporous calcium silicate + rigid polyurethane foam + outer steel pipe + glass fiber reinforced plastic shell anti-corrosion protection layer structure. Various pipe fitting nodes have mature heat preservation technology and reliable quality.

2. External sliding type: the heat preservation structure is composed of working steel pipe, glass wool heat preservation and heat insulation layer, aluminum foil reflection layer, stainless steel fastening steel belt, sliding guide bracket, air heat preservation layer, outer protection steel pipe, and outer anticorrosion layer.

External sliding insulation steel pipe structure form External sliding insulation steel pipe
1. Inner steel pipe 2. Zinc-rich primer 3. Sliding guide support 4. High temperature resistant glass wool 5. Aluminum foil reflective layer 6. Air insulation layer 7. Outer steel pipe 8. Outer steel pipe anticorrosive layer Steel sleeve steel composite heat preservation steel pipe is underground straight One of the buried pipelines, it can be buried directly underground without concrete structure, that is, the thermal expansion of the working steel pipe is carried out in the outer pipe, thereby reducing material costs, shortening the construction date, and ensuring the heating pipeline Safety, can be safer and widely used in different temperature environments, especially suitable for high-temperature steam pipeline projects. The operating temperature can reach 150℃-450℃. Pipe ports are generally sealed with polyethylene film or three-layer PE cold-wrap tape to prevent moisture or water from entering before installation or during construction. The multi-layer staggered wrapping of thermal insulation materials effectively reduces heat loss. At the same time, control measures are taken on the surface of the jacket to prevent the generation of cold bridges, so that the temperature control of the jacket anticorrosive layer is guaranteed. The multi-layer aluminum foil reflective layer is wrapped with thermal insulation material, which effectively reduces heat loss and makes the steam pipeline more economical and reasonable. The drainage system adopts a fully enclosed form, flexible layout, reasonable structure, safe and reliable. The moisture exhaust pipe on the steel casing can not only discharge humid gas in time, but also serve as an alarm signal pipe for daily operation. The thermal compensation of the pipeline adopts a high-quality corrugated pipe compensator and installs it in the casing to make it into a direct-buried form. There is no need to set up an observation well. The construction is convenient and the construction period is short. It is suitable for conveying steam or other media below 2.5MPa and 350 degrees Celsius. The product uses steel pipe as the outer protective layer, which has the advantages of high strength, not easy to damage, simple construction and maintenance, and long service life.

2. Polyurethane insulation steel pipe
On medium and small diameter heat-transporting crude oil or heating pipelines, in order to reduce heat dissipation from the pipeline to the soil, a thermal insulation composite layer is added to the outside of the pipeline. The commonly used thermal insulation material is rigid polyurethane foam, the applicable temperature is -185～120℃. This material has a soft texture. In order to improve its strength, a high-density polyethylene layer is added on the outside of the insulation layer to form a composite material structure to prevent groundwater from penetrating into the insulation layer. The high-pressure complete set of polyurethane foaming equipment is used to perform shot blasting and rust removal treatment on the outer surface of the steel pipe and corona treatment on the inner surface of the outer protective pipe to improve the bonding performance of the insulation pipe. The material of the insulation layer is rigid polyurethane foam with a density of 60kg/m3 to 80kg/m3, which fully fills the gap between the steel pipe and the casing, and has a certain bonding strength, so that the steel pipe, the outer casing and the insulation layer Form a solid whole. Polyurethane foam has good mechanical properties and thermal insulation properties. Under normal circumstances, it can withstand a temperature of 120℃, and can withstand a temperature of 180℃ through modification or combination with other insulation materials. The prefabricated polyurethane insulation steel pipe is divided into three layers from the inside to the outside: The first layer: working steel pipe layer According to the design and customer requirements generally choose seamless steel pipe, spiral steel pipe and straight seam steel pipe. After the surface of the steel pipe is treated by the advanced shot blasting process, the rust removal grade of the steel pipe can reach the Sa2 level in the GB8923-1988 standard, and the surface roughness can reach the R=12.5 micron in the GB6060.5-88 standard. Second layer: Polyurethane insulation layer: Using a high-pressure foaming machine to inject rigid polyurethane foam stock solution into the cavity formed between the steel pipe and the outer sheath at one time, it is commonly known as "tube-in-tube foaming". The third layer: high-density polyethylene protective layer: pre-made black or yellow polyethylene plastic pipe with a certain wall thickness. Polyethylene is odorless, non-toxic, feels like wax, and has excellent low temperature resistance. The lowest temperature can reach -70～-100℃. It has good chemical stability and can withstand most acids and alkalis (not resistant to oxidation Acid), insoluble in general solvents at room temperature, low water absorption, but because it is a linear molecule, it can slowly dissolve in some organic solvents without swelling, and has excellent electrical insulation properties. One of its functions is to protect the polyurethane insulation layer from damage by mechanical hard objects, and the other is to prevent corrosion and waterproof. High-density polyethylene polyurethane foam insulation steel pipe implementation: SY/T114-2000 and SY/T115-2001 standards. Advantages and characteristics of polyurethane insulation steel pipes: 1. Reduce project cost. According to the calculations of relevant departments, under normal circumstances, polyurethane insulation steel pipes can reduce the project cost by about 25% (using FRP as protective layer) and 10% (using high-density polyethylene as protective layer) . 2. Low heat loss and energy saving. The thermal conductivity of polyurethane is: λ=0.013-0.03kcal/m·h·oC, which is much lower than other commonly used pipe insulation materials in the past, and the insulation effect is increased by 4-9 times. Moreover, its water absorption rate is very low, about 0.2kg/m2. The reason for the low water absorption rate is that the closed cell rate of the polyurethane foam is as high as about 92%. Low thermal conductivity and low water absorption, coupled with insulation layer and high-density polyethylene or glass fiber reinforced plastic protective shell with good waterproof performance, has changed the traditional "worn jacket" situation of heating pipes laid in trenches, and greatly reduced the heat supply pipes. The overall heat loss, the heat loss of the heating network is 2%, far less than the international standard requirement of 10%. 3, anti-corrosion, good insulation performance, long service life Because the polyurethane rigid foam insulation layer is tightly bonded to the outer skin of the steel pipe, it isolates the infiltration of air and water and can play a good anti-corrosion effect. At the same time, its foaming cells are closed, and the water absorption is very small. Both HDPE shell and FRP shell have good anti-corrosion, insulation and mechanical properties. Therefore, the outer skin of the working steel pipe is hard to be corroded by outside air and water. As long as the internal water quality of the pipeline is treated well, according to foreign data, the service life can reach more than 50 years, which is 3 to 4 times longer than the service life of traditional trench laying and overhead laying.

Application of insulation steel pipe
Insulation steel pipe is suitable for conveying various media in the range of -50℃—150℃. It is widely used in the transportation of central heating, cooling and hot oil, as well as heat preservation and cold preservation projects in heating rooms, cold storage, coal mines, petroleum and chemical industries. .
Development status of thermal insulation steel pipe in China

Insulation steel pipe is an important factor affecting energy saving, and the development and application of insulation steel pipe have been paid more and more attention by countries all over the world. After the 1970s, foreign countries generally paid attention to the production and application of thermal insulation steel pipes, and strived to greatly reduce energy consumption, thereby reducing environmental pollution and the greenhouse effect. The foreign thermal insulation industry has a long history, and new thermal insulation materials are constantly emerging. Before 1980, the development of thermal insulation steel pipes in my country was very slow. The few thermal insulation plants could only produce a small amount of directly buried thermal insulation steel pipes. However, after more than 30 years of hard work in China’s thermal insulation industry, especially after nearly 10 years of rapid development, many Products from scratch, from single to diversified, quality from low to high, applications are becoming more and more common. Polyurethane material is currently the most commonly used insulation material in the world. Rigid polyurethane has many excellent properties and is widely used in the field of thermal insulation in European and American countries. Approximately 49% of thermal insulation materials in developed countries such as Europe and the United States are polyurethane materials, while in China this proportion is still less than 20%. Therefore, there is still a lot of room for the development of polyurethane insulation steel pipes in China.

Product Paramenters