How to choose rigid coupling and flexible coupling?

There are many types of grooved pipe fittings. Rigid coupling  and flexible coupling have similar functions, but they are used in different situations. During engineering construction, due to insufficient technical explanation and quality control, workers often use rigid coupling and flexible coupling without distinction, which brings hidden dangers to the reliable operation and normal maintenance of the entire pipeline system. For example: in a domestic hot water system, the difference between the system operating temperature and the temperature during pipe installation can reach 60°C. If the steel pipe is 6m long, the thermal expansion stress generated will reach 1200kg/mm2. If the pipes are rigidly connected, this will cause the brackets to deform and lead to damage to the piping system. Therefore, joints and fittings should be distinguished and reasonably selected.
① Domestic hot water pipes, air-conditioning water pipes, and open-air pipes. In order to effectively compensate for pipe displacement caused by thermal expansion and contraction, flexible coupling must be used for the above three categories. If the displacement of the expansion section exceeds the total compensation amount of the flexible coupling, you should also consider installing metal expansion joints.
② Pipes with little temperature difference change, such as indoor firefighting pipes, can use a large number of rigid joints. However, a certain number of flexible coupling should be installed in the middle section of the long straight pipe to compensate for the small amount of thermal expansion of the long straight pipe section and ensure that the entire pipeline system is in safe operation.
③ For bent pipes and zigzag pipes with temperature compensation function, flexible coupling should be installed on the pipe sections that produce angular displacement.
④ It is recommended to use flexible coupling for pump room piping to reduce noise and weaken vibration transmission.
⑤ Flexible coupling should be used for buried pipelines, which can effectively cope with local deformation of the pipeline system caused by uneven settlement.
⑥Flexible coupling must be used to connect small arc-shaped pipes. You can first assemble according to the straight line pipe, and then bend the pipe to make it reach the predetermined corner. However, under no circumstances shall the angle of rotation exceed the value specified in the instructions for the grooved pipe fittings.
Shandong Zhihua Pipe Industry provides you with the highest quality grooved pipe fittings, including not only rigid coupling and flexible coupling, but also various different options such as reducing clamps and quick-release clamps. Our products are made of high-quality ductile iron with higher strength and better durability. They also have multiple industry standard certifications such as FM and UL, ensuring that you don't have to worry about product quality. Whether it is standard parts or customized products, you can find the grooved pipe fittings you need in Zhihua. At the same time, we provide one-stop solution services. If you have any needs, we will provide you with the most sincere service so that you can Choose the most suitable and reliable product! Welcome to inquire and look forward to cooperating with you!