The ferrule type pipe joint has the advantages of simple structure, convenient use and no welding. However, in the medium and high pressure hydraulic system, improper operation will often cause leakage, affecting its popularization and use.
(1) Pre-installed
①The pre-installation of the ferrule type pipe joint is the most important link, which directly affects the reliability of the seal.
②The end face of the pipe should be flush. After the pipe is cut off, it should be polished on a grinding wheel and other tools, and the burrs should be removed, cleaned and blown with high-pressure air before use.
③ During pre-installation, the coaxiality of the pipe and the joint body should be kept as far as possible. If the deflection of the pipe is too large, the seal will fail.
④The preloading force should not be too large. The inner edge of the ferrule should be just embedded in the outer wall of the pipe, and the ferrule should not be significantly deformed. When connecting the pipes, assemble them according to the specified tightening force. If the ferrule is severely deformed during pre-installation, the sealing effect will be lost.
(2) It is forbidden to add fillers such as sealant. In order to achieve better sealing effect, some people apply sealant on the ferrule, as a result, the sealant is flushed into the hydraulic system, causing failures such as blockage of the orifice of hydraulic components.
(3) When connecting the pipeline, the pipe should have enough deformation allowance to avoid the pipe being subjected to tensile stress.
(4) When connecting the pipeline, it should be avoided to be subjected to lateral force. If the lateral force is too large, the sealing will not be tight.
(5) When connecting the pipeline, it should be tightened at one time to avoid multiple disassembly, otherwise the sealing performance will be deteriorated.