After the PVC transparent steel wire hose is produced, the general manufacturer needs to carry out the relevant vacuum performance test. The standard is the experimental method for the shape change of the inner and outer surfaces of the hose after the suction hose is evacuated to the specified negative pressure. There are two kinds, let's take a look at it.
First of all, in terms of the length of the test hose, the minimum length, excluding the end hose joint, should be five times the nominal inner diameter of the hose, or 1 meter long. For the two data, you can choose A long value, for some cases less than 1 meter in length, can take the entire hose or hose assembly. For some hoses with an inner diameter of 80 mm or less, we generally need to place the hose as flat as possible on a flat surface, and use a metal plug to block one end so that it does not leak. At this time, a solid ball is inserted into the inside of the hose, and then the open end of the hose needs to be connected to a vacuum pump with a vacuum gauge. Within 60 seconds, we need to reduce the internal pressure value of the hose to the specified experimental pressure value. And keep this value for at least 10 minutes. During the process of maintaining the test pressure, we can also check whether there is any depression on the outside of the transparent steel wire hose. Finally, we need to tilt the test hose so that the internal solid ball can be The entire hose is passed inside, and remember to check the hose for any other malfunctions.