Benzene is an important basic petrochemical raw material, its storage and transportation temperature is generally 15-20 ℃, 80 ℃ boiling point, toxic, and its crystallization temperature is about 5 ℃. In the northern region due to climatic reasons benzene raw material is prone to solidification phenomenon, and benzene transport pipeline is long, up to thousands of meters.

                    In the choice of accompanying heat, if choose steam accompanying heat, the temperature is not good control, high temperature will also lead to benzene gasification, long distance pipeline along the way need to have more than one steam joining point and hydrophobic point, and there will be the phenomenon of running leakage and dripping, and at the same time, the steam will corrode the pipeline, affecting the normal production. Based on these reasons, many petrochemical enterprises began to use electric accompanying heat.

　　             Selection of electric heating cable need to consider the following several factors:1.

　　             1. Accompanying heat temperature should not be too high, precise temperature control.

　　             2. Accompanying heat length

　　             3. Safety.

                 Benzene pipeline in the choice of electric heating cable products, large tanks should use series constant power electric heat tape, electric heating cable by the set temperature of the temperature can be through the multi-point sensor + temperature controller︰ realize 10~15°C accompanied by heat. Specifically has the following advantages.
　　           1, length control flexibility
　　           2、Will not cause the local material temperature is too high
　　           3、Easy to control and save energy
　　           4、If the control has failed can be forced to run, can still meet the safety requirements. In addition, like some small tanks and short distance pipeline, can use parallel constant power electric heating cable and self-limiting electric heating cable.