Seal performance After the box is sealed, inflate to 100kPa inwards (inflation only apply to the models with the air hole), and then soak it in the water of normal temperature, after 15 minutes of steady observation, there is no bubble to overflow.
The insulation resistance between the metal work piece and the earth is greater than 20kMΩ.
Pressurization: there is no breakdown or flashover under 15kVdc/1min between the metal work piece and the earth.
The curvature radius of the fiber 40mm, without extra loss inside the splice tray.
It can bear the axial tensile strength no less than 1000N.
Lifetime: 25 years.
Other performances are all in accordance with the requirement of standard YD/T814-1998.