1) The Shore hardness of the sealing ring is 45~50 degrees, otherwise it will be lost. When wiring, the layered side of the sealing ring should face the inside of the wiring cavity, otherwise it is not intact (except for coal drill).

2) The size of the sealing ring must meet the following requirements. If one item fails to meet the requirements, it will be a loss of explosion.

① A. If the outer diameter of the sealing ring is less than or equal to 20mm, the difference between the outer diameter of the sealing ring and the inner diameter of the wiring device is less than or equal to 1mm

B, the outer diameter of the sealing ring is less than 60mm or greater than 20mm, and the difference between the outer diameter of the sealing ring and the inner diameter of the wiring device is less than or equal to 1.5mm.

C, the outer diameter of the sealing ring is greater than 60mm, the difference between the outer diameter of the sealing ring and the inner diameter of the wiring device is less than or equal to 2mm

The difference between the inner diameter of the sealing ring and the outer diameter of the cable is less than 1mm.

The width of the sealing ring shall not be less than 0.7 times of the outer diameter of the cable and not less than 10mm.

The thickness of the sealing ring is not less than 0.3 times the outer diameter of the cable (except for the cable with 70mm2) and not less than 4mm.

3) The sealing ring is not damaged and shall not be cut open for use. No other objects shall be wrapped between the cable and the sealing ring.

4), not through the cable connection nozzle with sealing ring and thickness of not less than 2mm steel baffle plug tight. The sealing ring is placed in the steel baffle.

5) The wire nozzle is pressed with allowance, and a metal gasket is installed between the wire nozzle and the sealing ring.

(1) the gap between the outer diameter of the rubber ring and the inner diameter of the chamber is not more than 2mm mm (2) the gap between the inner diameter of the rubber ring and the outer diameter of the incoming cable is not more than l mm;(3) multiple cables are not allowed to penetrate into the single hole of the sealing ring;(4) The sealing ring is not allowed to be cut and sleeved on the cable;(5) No other bandage is allowed between the sealing ring and the cable sheath.