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The design and selection of the structures for pipe supports and hangers are important aspects of pipeline system design. In addition to supporting the weight of the pipes, specialized pipe supports can balance the forces acting on the pipeline system, limit pipe displacement, and absorb vibrations. When designing a pipeline system, choosing and arranging pipe supports with appropriate structures can improve the stress distribution within the pipes as well as the forces exerted on the pipe supports, thereby ensuring the safe operation of the pipeline system and extending its service life. How is the position of pipe supports and hangers determined? The key points for determining the location of pipe supports and hangers are as follows. (1) Meet the requirements for the maximum allowable span of the pipeline. (2) In the presence of concentrated loads, the supports should be placed near the load to reduce eccentric loads and bending stresses. (3) Near sensitive equipment (pumps, compressors, etc.), supports should be installed to prevent the pipeline loads from acting on the equipment nozzles. (4) The suction or discharge pipes of reciprocating compressors, as well as other pipes subject to severe vibration, should be equipped with separate supports. These supports should be anchored to pipe pedestals or pipe racks on the ground and separated from the building, in order to prevent vibrations from being transmitted to the building. (5) Except for pipes that vibrate, building or structure beams and columns should be utilized as much as possible as anchorage points for the supports, taking into account the load that these anchorage points can bear; the design of these anchorage points must meet the requirements of the fixing elements. (6) For complex pipelines, especially those that require detailed stress calculations, the positions of their supports and hangers should also be adjusted based on the results of those stress calculations. (7) It should be located in a position that does not interfere with the connection and maintenance of pipelines and equipment. (8) It should be located near elbow pipes and large-diameter tee branch pipes. (9) Support brackets should be considered for the outlet pipeline of the safety pressure relief device as needed. What are the types of pipe supports and hangers? Brackets and supports can be classified into 3 categories based on their function: fixing brackets, guiding brackets, and supporting brackets (or one-way thrust brakes) ； Based on their mechanical properties, supports and hangers can be further divided into rigid supports and elastic supports. First, rigid brackets. Theoretically, a rigid support has infinite stiffness and does not deform under external loads; it is generally used in applications where there is no vertical displacement. Second, the springs of elastic supports all possess a certain stiffness, and they can deform (move) under the action of external forces. Within the operating range of the spring, when the pipeline undergoes slight deformation, the spring bracket does not completely lose its ability to distribute loads, thereby controlling the amount of load transfer. Spring supports are generally used in areas where the pipe sections experience thermal displacement in the vertical direction, which causes movement at the pipe supports. If these supports are rigid, they will prevent the pipe sections from moving, or may cause the sections to become detached from the supports, resulting in excessive forces and stresses on the pipes. This phenomenon does not occur if bellows supports or pipe hangers are used. Third, spring supports are divided into two main categories: variable spring supports and constant-force spring supports. The characteristic of variable spring supports is that when the piping system moves vertically, the spring compresses or expands, resulting in changes in the forces acting on the support points. The load on the piping system at these support points is then redistributed to nearby support points; generally, a range of 25% for the rate of load change is specified. Constant-force spring supports maintain a constant load when the piping system undergoes vertical displacement; in other words, the rate of change of their load is theoretically zero. Such supports are suitable for piping systems that experience significant vertical displacement, or in situations where a strict control over the rate of load change is required. For pipes and equipment supported by constant-force spring hangers, a constant supporting force is also maintained when displacement occurs, thus avoiding any additional forces and stresses on the pipes and equipment. It prevents adverse force transfer in the piping system, ensuring the proper operation of the pipes and equipment. Principles for selecting pipe supports and hangers: (1) When selecting pipe supports and hangers, appropriate ones should be chosen based on factors such as the magnitude and direction of the loads borne by the support points, the displacement of the pipes, the operating temperature, whether insulation or cooling is required, and the material of the pipes. (2) Standard pipe supports, pipe clamps, and pipe hangers should be used as much as possible during design. Welded-type pipe supports and hangers consume less steel, are easier to manufacture, and facilitate construction compared to clamp-type pipe supports and hangers. Therefore, except in the following cases, welded type pipe supports and pipe hangers should be used as much as possible: ① Pipes made of carbon steel with a medium temperature inside the pipe of ≥400°C ； ②Low-temperature pipeline ； ③Pipes made of alloy steel ； ④Pipelines that need to be frequently disassembled for maintenance during production ； ⑤Pipes laid overhead and difficult to weld during installation ； ⑥Non-metallic lined pipes. (3) To prevent excessive lateral displacement of the pipeline as well as potential impact loads, ensuring that the pipeline moves only axially; guide supports are generally installed on pipelines under the following conditions: ① High-speed vent pipes at the outlet of safety valves and two-phase flow pipes that may experience vibration ； ②Excessive lateral displacement affects adjacent pipes ； ③If the distance between the fixed supports is too large, it may lead to lateral instability ； ④Pipelines for which excessive lateral displacement is not allowed to prevent leakage at flanges and unions. (4) For overhead pipes with a thermal expansion amount exceeding 100 mm, extended pipe supports should be used to prevent the supports from falling under the pipe bridges. (5) The brackets take root on the steel equipment; if heat treatment is required for the equipment, special shims should be provided to the relevant party. When the equipment is made of alloy, the backing plate material should be the same as that of the equipment. (6) For support locations where rooting occurs on equipment or civil engineering platforms and where heavy loads are involved, the elevation and load requirements should be discussed in advance with the relevant departments. (7) Whenever it is necessary to limit the amount of pipe displacement, consideration should be given to installing limit frames. (8) When there is displacement in the vertical direction, spring hangers can be selected ； Springs can be used in parallel and in series depending on the specific circumstances. (9) When the pipeline experiences vertical displacement at the support points and it is required that the variation in supporting force remains within 6%, constant-force spring supports should be used for the piping system. (10) When no suitable support or hanger can be selected from the general drawings for pipe supports and hangers, other special types of supports and hangers can be used. Summary by the Seismic Bracing Network: Among all the investments in a piping project, although the proportion allocated to the bracing and hanger systems is relatively small, these systems play a crucial role in ensuring the safe operation of the entire piping system ； The design of pipe supports and hangers is closely related to the stress in the piping system; by installing such supports and hangers, it is possible to limit forces or displacements in certain directions, thereby keeping the piping system in a safe state.