包建管道铁路公司去年敷设了一条φ1420×12毫米的钢管线。接口采用捍接,外焊两遍,内焊一遍,根据设计要求,钢管的外部用沥青玛(王帝)脂蔴布防腐,然后每30米一段进行组装。夏季,由于防腐层吸收的太阳辐射热,使得管内的窒气温度升高,再加上焊接熔化的热量,管内的空气温度达50℃以上;又因焊条药皮 The Baojian Pipeline Company laid a φ1420×12 mm steel pipe line last year. The interface is spliced, welded externally twice and welded inwards. According to the design requirements, the outside of the steel pipe is greased with asphalt (Majestic) grease and then assembled every 30 meters. In summer, due to the solar radiant heat absorbed by the anti-corrosion layer, the temperature of the helium in the pipe rises, plus the heat of welding and melting, the temperature of the air in the pipe reaches above 50°C;