Pipeline vibration problems in reciprocating compressors

To eliminate device vibration caused by airflow pressure fluctuations, the following methods are often employed: Adding pipe supports: 1. Pipe supports should be added as close as possible to the points where the amplitude is highest. 2. Pipe clamps should be installed at both ends near the elbow, as well as on the three branch pipes near the tee junction. It should not be fixed rigidly at just one point, but rather at multiple locations to minimize the additional stress on the pipeline as much as possible. 3. Install pipe clamps at the vibration source as much as possible. 4. Design the strength and stiffness of the pipe rack based on the direction of the excitation force. 5. The pipeline should be fixed in its natural state; avoid applying forces that create additional loads. 6. In environments with vibration, direct friction between pipes, between pipes and pipe supports, and between pipes and fastening bolts should be avoided. Add orifice plates (vibrations caused by large airflow pulsations): 1. Orifice plate dimensions: opening ratio d/D = 0.43~0.5, thickness h = 3~5 mm. 2. The inner hole of the orifice plate has no chamfer. 3. Vibration of the pipeline in front of the container; the orifice plate is installed near the flange at the front of the container ； Vibration in the pipeline behind the container; the orifice plate is installed near the flange at the back of the container. Design and modify pipelines: 1. Shorten the pipe length as much as possible to reduce the number of elbows, reducers, etc., thereby decreasing the excitation forces. 2. Avoid the resonant tube length. 3. Use a larger pipe bending radius to enhance the damping effect of pulsations. 4. The mechanical vibration frequency can be altered by increasing the stiffness and mass of the piping system, either by adding pipe supports or by enlarging the diameter or thickness of the pipes (provided that the strength requirements and process specifications are met). Add buffers: 1. There must be space for installation and maintenance. 2. The buffer should be as close to the cylinder as possible. 3. The buffer volume is large enough. Add acoustic filter: 1. The nominal diameter D” of the container is 4 times the inner diameter d of the pipe. 2. The container length L is 12~16d. 3. The flow cross-sectional area of the tubed pipe is equal to or greater than that of the intake pipe. 4. The diameter of the small holes in the perforated tube is 1/4 of the diameter of the tube, and the distance between adjacent holes is 1/3 of the diameter of the tube. Others: 1. If there is still some vibration despite taking a series of vibration-damping measures, or if it is difficult to eliminate the vibration due to certain constraints, reinforce plates can be added at the root of the pipe to reduce local stress there and gradually release the vibration-induced stress. This method is effective in preventing vibration-induced cracks in reducer tees or small pipes. 2. Vibration in the pipelines of standby equipment is caused by the presence of dead sections; this vibration can be completely eliminated by adding valves to cut off the air columns in those dead sections.

Without any calculations, based on my personal experience, the following guidelines apply: 1. The inlets should be arranged symmetrically; high pipe supports should be installed at the inlets, along with shock-absorbing friction brackets. 2. Pipe supports must also be installed near the outlets, using guide-like pipe clamps for fixation. A asbestos pad of about 4 mm should be placed between the guide plate and the guide bracket plate to ensure proper compression. 3. Depending on the pipe diameter (the diameter of the inlet and outlet pipes is not known), additional pipe supports should be installed to reduce the amplitude of pipeline vibration

Factors such as stress concentration at the flange diameter when tightening the pipeline flange bolts, and inadequate fixation in areas like pipeline elbows.

The second floor covered it very comprehensively. In cases where vibration in existing pipeline systems occurred, modifying the pipeline layout and adding supports proved to be an effective solution.

It is expensive and not suitable; it can be used as a short-term backup, but care should be taken to avoid using it in enclosed spaces or areas with poor ventilation, as it can cause suffocation.