Leakage caused by improper operation of ferrule fittings

In fact, the card sleeve 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 and affect its promotion and use.

Note for card sleeve type pipe joints: It is forbidden to add fillers such as sealants. In order to obtain a better sealing effect, some people apply a sealant on the ferrule. As a result, the sealant is flushed into the hydraulic system, causing failures such as clogging of the male and female holes of hydraulic components. When connecting the pipeline, the pipe should have sufficient deformation margin to avoid subjecting the pipe to tensile force. When connecting pipelines, avoid subjecting them to lateral forces. Excessive lateral forces can cause tight seals. When connecting the pipeline, it should be good at one time to avoid multiple disassembly, otherwise the sealing performance will be deteriorated.

Pre-installation of the ferrule:

Pre-assembly is the most important part of the ferrule, which directly affects the reliability of the seal. Generally, a special pre-conditioner is required, and the joint with a small diameter can be pre-installed on a vise. Card sleeve type pipe joints mainly include card sleeve type straight pipe joints, card sleeve type ends, straight through joints, and card sleeve type tee joints. Even with a batch of goods from the same manufacturer, the depth of the tapered holes in these types of joint bodies is often different, resulting in leakage, and this problem is often ignored. The correct approach is to use what kind of joint body to connect one end of the pipe, and the corresponding connection end is pre-installed with the same type of joint, so as to avoid leakage problems to the greatest extent.

The end face of the pipe should be flush. After the pipe is cut, it should be polished and evened on a tool such as a grinding wheel, and the burrs should be removed, washed and blown with high-pressure air before use. When pre-installed, the concentricity between the pipe and the joint body should be maintained as much as possible. If the pipe is too deflected, the seal will fail. The pre-installation force should not be too large so that the inner edge of the ferrule just fits into the outer wall of the pipe, and the ferrule should not have obvious deformation. When connecting the pipes, assemble them with the specified tightening force.

Installation of card sleeve type pipe joints: Pipes that need to be pickled should be pickled as required; cut the pipes with sawing machines or special pipe cutters according to the required length. Never use melting (such as flame cutting) or abrasive wheels to cut. ; Remove the internal and external round burrs, metal chips and dirt from the pipe end; Remove the rust inhibitor and dirt from the pipe joint; At the same time, ensure the roundness of the pipe; Put the nut and ferrule into the pipe one by one, and the front edge of the ferrule (small diameter end) At least 3mm away from the pipe opening, then insert the pipe into the taper hole of the connector body, as far as it will go; slowly tighten the nut, while turning the pipe until it does not move, then tighten the nut 2/3 ～ 4/3 turn; disassemble and check whether the ferrule The pipe has been cut in, and the position is correct. The ferrule is not allowed to move axially and can be slightly rotated; re-tighten the nut after inspection.