第1层：工作钢管层
Layer 1: Working Steel Tube Layer
依据设计和客户的请求普通选用无缝管(GB8163-87)螺旋焊管(GB9711-88;SY/T5038-92)和直缝焊管(GB3092-93)。
Seamless pipe (GB8163-87), spiral welded pipe (GB9711-88; SY/T5038-92) and straight welded pipe (GB3092-93) are usually selected according to design and customer's request.
钢管外表经过的抛丸除锈工艺处置后，钢管除锈等级可达GB8923-1988规范中的Sa2级，外表粗糙度可达GB6060.5-88规范中R=12.5微米
After the surface of steel tube is treated by advanced shot peening rust removal technology, the grade of steel tube rust removal can reach Sa2 level in GB8923-1988 specification, and the surface roughness can reach R=12.5 micron in GB6060.5-88 specification.
第2层：聚氨酯保温层
Layer 2: Polyurethane Thermal Insulation Layer
用高压发泡机在钢管于外护层之间构成的空腔中一次性注入硬质聚氨酯泡沫塑料原液而成。即俗称的“管中管发泡工艺”。其作用一是防水，二是保温，三是支撑热网自重。当保送介质温度为：-50℃—120℃时，选用硬质聚脲酸酯泡沫塑料做保温层。
A rigid polyurethane foam plastics raw liquid is injected into the cavity formed between the steel pipe and the outer protective layer by a high-pressure foaming machine at one time. That is commonly known as "tube-in-tube foaming process". Its function is waterproof, heat preservation and self-weight support of heat network. The rigid polyurethane foam is chosen as insulation layer when the temperature of delivery medium is -50 ~120 ~C.
第3层：高密度聚乙烯维护层
Layer 3: High Density Polyethylene Maintenance Layer
预制成一定壁厚的黑色(黄色)塑料管材，其作用一是维护聚氨酯保温层免遭机械硬物毁坏，二是防腐防水增强级聚氨酯保温钢管特 点：用钢管做外维护层，具有强度高。不易损坏且能接受较大上部荷载的特性，为到达短命命，对钢外套管需停止防腐处置。滚动支持构造设计合理，滚动摩擦力小，固定支座受力减小，其力学剖析原理简单，管道稳定性、平安性得到较大进步。真空层彻底根绝了空气层存在的热传导和热对流、极大地降低了热损失。与空气层构造相比，在同等保温厚度下可降低外壁温度8-13°c。抽真空安装彻底处理了外钢套管内壁容易被热湿空气腐蚀的难题，大大进步了直埋蒸汽管道的运转寿命。产品寿命进步到30年。
Prefabricated black (yellow) plastic pipes with a certain wall thickness. Its function is to protect the polyurethane insulation layer from mechanical damage. The second is the characteristics of anti-corrosion, waterproof and reinforced polyurethane insulation pipes: using steel pipes as external maintenance layer, it has high strength. It is not easy to damage and can accept large upper load. In order to achieve short life, the steel casing should be stopped anti-corrosion treatment. The design of rolling support structure is reasonable, the rolling friction is small, the force of fixed support is reduced, the mechanical analysis principle is simple, and the stability and safety of pipeline have been greatly improved. The vacuum layer completely eliminated the heat conduction and convection in the air layer and greatly reduced the heat loss. Compared with the air layer structure, the outer wall temperature can be reduced by 8-13 C under the same thermal insulation thickness. Vacuum extraction installation has thoroughly solved the problem that the inner wall of the outer steel casing is easily corroded by hot and humid air, and greatly improved the operation life of the directly buried steam pipeline. The product life has been improved to 30 years.
This article is supported by polyurethane insulating steel pipe manufacturer. For more details, please click on our official website at http://www.sdhpgy.com. We will provide you with satisfactory service wholeheartedly.
