There are two commonly used laying methods for electric heat tracing, one is straight laying method and the other is winding method; Straight laying refers to the laying method in which the laying direction of the cable is consistent with the direction of the pipeline, and the length is proportional to the length of the pipeline; Winding refers to the laying method in which the cable is fixed in a winding manner on the surface of the heat trace object. Under normal circumstances, when referring to the installation method of straight and winding, the installation object is often aimed at the pipeline, because on the surface of the irregular heat tracing object of equipment and instrument lights, the cable can not be installed and laid in the form of straight laying, so only when the electric cable is installed on the pipeline, the two laying methods will be mentioned.
Under normal circumstances, the installation method of straight paving is relatively simple, the construction requirements are relatively low, and the requirements for the cable are relatively small, suitable for a variety of different pipe diameters of the pipeline, as long as the heat trace unit output power is greater than or equal to the premise of the system calculating heat loss, you can use this method for installation and construction, often the length of the cable will be an integer multiple of the length of the pipeline, such as the heat trace ratio of 1 to 1 or 1 to 2 and so on.
Winding method is relatively complex compared to straight paving, the pipe, heat trace and construction requirements are slightly more complex than straight paving, because the cable is fixed on the surface of the heat trace pipeline in a winding manner, so the bending radius and material of the cable are relatively high, so the difficulty of construction and installation is relatively large. Of course, whether straight or wound, there are some basic guidelines for cable installation that must be followed.
First, the heat trace is strictly forbidden to overlap, as a heating device, the overlap of the heat trace will cause the accumulation and superposition of heat at the overlapping point, causing serious damage to the cable itself, whether it is self-limiting temperature tracing or constant power tracing are no exception, even if the self-limiting temperature trace will adjust the output power due to temperature changes, and do everything possible to avoid the overlap of the cable during installation.
Self-limiting temperature electric heat tracing uses instrument valves that can be cross-wound
Constant power electric tracing uses large-diameter pipes and can choose multiple parallel straight lines
Second, laying the cable on the pipeline, it is inevitable to encounter flanges, valves, elbows and brackets, etc., in order to ensure that in the daily maintenance after the laying of the cable, it is necessary to replace the valve, disassemble the pipeline, maintain the instrument, etc., it is recommended to reserve a certain amount of the cable in the construction and installation of the above part, and the installation needs to consider the disassembly and maintenance of the corresponding parts.
Third, the laying of the cable must comply with the design requirements and pipeline conditions, and the installation method and installation quantity of the cable cannot be arbitrarily changed due to convenient construction or changes in the situation.
Fourth, the laying of the cable is often not the last stage of the entire construction operation, so after the laying of the cable is completed, the influence of the subsequent construction team should be avoided as much as possible under the condition of ensuring the performance conditions, including the damage caused by external forces such as stampede, collision, and cutting.
