Installation of heat tracing pipes in storage and transportation systems

Installation of jacket pipes and heat tracing pipelines I. Jacket pipe installation Construction procedures: Technical briefing, drawing of single-line diagrams, determination of the geometric dimensions of the inner pipe, use of positioning plates (support blocks), partial welding, determination of the geometric dimensions and accessories of the outer pipe, partial welding, degreasing of the pipes, fitting of the outer pipe, identification of the area to be adjusted on the semi-pipe, measurement of geometric dimensions, inspection tests for the inner pipe, strength and tightness tests, drying and sealing, welding of the outer pipe, cleaning of the interior cavity of the jacket, final sealing of the adjusted semi-pipe, further inspection and drying/sealing, numbering of prefabricated components, registration and fixation, preparation for installation, on-site installation, system testing, purging, and handover acceptance. II. Construction Preparation 2: Be familiar with the drawings. 2 Before starting work, provide technical briefings to all personnel involved in the construction, so that they fully understand the project requirements, the challenges involved in the construction, and the technical specifications. 2 Prepare construction machinery and tools. 2 Prepare the construction schedule. 2 Material planning and procurement. III. Basic construction requirements 2: When performing TIG welding, wind speeds above 2 m/s require the use of wind protection measures, and welders must hold valid certificates to work. 2 Before construction, the dimensions of various components, as well as the materials and fittings to be used, must be carefully checked. The assembly procedure should be planned properly to minimize the number of welds required. 2 After the inner pipe has been constructed and passed the inspections, and after strength and tightness tests have been completed, the outer pipe can be welded shut. 2 The pipes, piping fittings, and valves used for the bushing shall be accompanied by certificates of conformity from the manufacturer. Pipes, fittings, valves, and other components made of different materials must be properly stored and maintained to prevent confusion and damage. 2 The appearance of various stamped pipe fittings shall be free from defects such as cracks, folds, inclusions, and double skins. 2 The springs used for the supports and hangers of the bushings shall have a design, dimensions, and material that meet the requirements specified in the design. The springs for supports and hangers shall come with a certificate of conformity from the manufacturer. IV. Fabrication of the inner and outer tubes 2. The cutting and beveling of the tubes should not be carried out using manual flame cutting; plasma cutting or mechanical methods should be employed instead ； The perpendicularity of the pipe end face should also be ensured. 2 There is jacket processing and jacket installation; the groove types of the inner and outer tubes as well as the alignment gap must meet the requirements of the welding process. Regarding the misalignment amount: the deviation of the central tube is 0.15 times the wall thickness, and shall not exceed 1 mm ； The deviation of the outer tube shall be 0.15 times the wall thickness and not exceed 2 mm. 2 When manufacturing the outer pipe section, it should be 50~100 mm shorter than the corresponding inner pipe section to facilitate various inspections and tests of the inner pipe. The seal welding of the outer tube is compensated by adjusting the actual dimensions of the half-tube. 2 The fabrication of the cladding sleeve must ensure its straightness, horizontal turning angles, and the accuracy of three-dimensional turning angles. Its geometric dimensions are strictly controlled using a platform and a set square. 2 For cross welds, weld the long straight seams first, and then weld the circumferential seams. 2 The welds of the inner and outer tubes of the jacket are not allowed to be on the same cross-section; they must be offset from each other. 2 After cutting, the steel pipes should have their material specifications and other relevant markings transferred to each pipe segment promptly to avoid errors. 2. A positioning block made of the same material as the inner wall of the jacket tube should be welded to it in order to maintain the gap between the inner and outer tubes. VI. Installation of jacket pipes 2 The installation of jacket pipes should be carried out after the construction of the building is largely complete, and after the equipment related to the piping systems as well as the supports and hangers have been installed, fixed, and leveled. Moreover, the jacket pipes should be installed before the adjacent individual piping systems. 2 Before installing the cladding tubes, for each prefabricated system, valves, instrumentation components, etc. must be carefully checked to ensure they conform to the design drawings; only after that should the inner tube be cleaned and inspected. Only after verification may it be installed in place and the connections sealed. 2 The coordinates, elevation level, and verticality of the clamp sleeve installation shall meet the design requirements. 2 The connectors attached to the jacketing (thermometers, pressure gauge fittings, etc.) should be installed during the fabrication of the jacketing. 2 Flange connections shall use bolts and nuts of the same material and specification. The nuts should be on the same side, and the fastening bolts should be tightened symmetrically and evenly, with an appropriate tightness such that 2–3 threads are visible. 2 For jacketed pipes designed with a slope, the specified slope value must be maintained; shims used to adjust the installation slope shall not be placed between the pipe and the pipe support, but only under the base plate of the pipe support. 2 Before installing the cladding sleeves, for the prefabricated systems and sections, the valves, instrumentation components, etc. required must be numbered according to the design drawings on a section-by-section basis, and the actual items must be carefully verified. At the points where the jacket pipe passes through walls, platforms, and floor slabs, sleeves and water-blocking rings should be installed. The layout of the weld positions in the double-pipe jacket shall comply with the following requirements: for the butt welds between straight pipe sections, the distance for the inner pipe shall be no less than 200 mm, and that for the outer pipe shall be no less than 100 mm. . 2 The circumferential welds should be at least 100 mm away from the pipe rack, and must not be located at wall or floor penetrations. 2 The longitudinal welds on the outer wall of horizontal pipe sections should be located in areas that are easy to access for maintenance. 2 No openings or branch pipes shall be made on the inner pipe welds. Holes and branch connections should be avoided as much as possible on the outer pipe welds.

Are you in the construction industry? May I ask how the heat tracing pipes in storage and transportation systems are installed? Do you have any photos from the site?

For the heat tracing pipes installed in the tank area, are they connected directly to the main steam pipe, or are there distributors from which the pipes branch off?

Using steam for heating involves more complications; one has to take into account thermal expansion as well as condensate drainage. If possible, it’s better to use electric heating – it requires only an initial investment, is easier to maintain, and allows for precise temperature control.

Electric heating – I haven’t dealt with that yet. Do you have any information on it? Could you share it?

The diameter of the heating pipeline, as well as the heating medium to be used, are determined by the diameter of the pipeline being heated. Hot water heating is the most economical option; installing a valve assembly on the main line is the best way to ensure easy operation. :)

I heard that there is now a new electric heating system installed in storage tanks, which is energy-efficient and safe. I wonder if anyone has practical experience in this type of project and could share it.

Installation of heating pipes for the asphalt heat transfer oil system?

The original poster had better mention what the medium of the main line is first, so we can make a judgment :)

The type of heat tracing to be used should be determined based on the medium inside the pipeline.

Setting up the distributor is also related to the number of heat tracing pipes, right? For 2 or 3 heat tracing pipes, I think it’s sufficient to connect them directly to the main pipe. I’m not sure if there are any specific regulations! !

Do some statistics on which types of media require which type of heat tracing, so that everyone can share this information.