Generally, flexible metal vacuum hoses can be divided into 3 lengths:

　　The first type of flexible metal vacuum hose is the compression length, that is, the length when the hose is compressed to the limit position; the second type is the installation length, which is the length of the hose when it is in the middle position of half the maximum displacement; flexible metal The third type of vacuum hose is the stretch length, which is the length when the hose is stretched to the maximum limit.

　　When installing the flexible metal vacuum hose, the hose should be in the middle position, which is the so-called installation length. When installed in this position, the hose can have two moving directions when it is subjected to an axial load. Otherwise, if it can only move in one direction, it will affect the strength of the metal hose and reduce its service life.

　　In the actual installation process of the flexible metal vacuum hose, considering that using a ruler to measure the length of the hose according to the calculation result and then installing it may affect the production efficiency, some foreign manufacturers install the ruler directly on the hose, and put the ruler after installation. cut out. The hose can be installed horizontally, vertically or obliquely. The most ideal state is vertical installation. At the same time, it should be avoided to be installed near the wheels. If necessary, a baffle can be installed.