Precautions for selecting explosion-proof flexible hoses for explosion-proof motors
2021-02-22 12:07
Key points for selecting explosion-proof motor explosion-proof hose parameters ：
1. Both ends of the explosion-proof hose can be made into metric or British threads, with metric threads being widely used. 2. The explosion-proof hose sheath can be made into structures such as metal mesh braided sheath, rubber sheath, and plastic sheath. 3. The nominal diameter of the explosion-proof hose is 25、32、38、50、64、75、100 mm; the hose length is 700、800、1000、1200、1400 mm or any cut length. 4. Ambient temperature: There is no limit to the temperature of hoses protected by metal mesh braided sheaths, while rubber sheathed hoses are generally -20~60 , and plastic sheathed hoses are generally 5~40 . When a protective hose with high-quality rubber or plastic sheathing passes inspections for other ambient temperature ranges, the ambient temperature range can be expanded accordingly. 5. The explosion-proof hose consists of a pipe fitting and a connecting pipe; the connecting pipe consists of an inner pipe and a sheath.
6. Pipe fittings should be made of rolled metal materials that are not easily corroded or electroplated. It is recommended to use galvanized A3 steel. The pitch of the fitting threads should not be less than 0.75 mm and not greater than 3 mm; the effective number of threaded engagements should not be less than 6 threads, and the pitch length should not be less than 9 mm.
7. The inner pipe uses a metal corrugated pipe and a metal hose. It is recommended to use a metal hose, which should be made of stainless steel or electroplated material, and the inner pipe should be smooth and free of burrs.
Technical requirements for explosion-proof motor power distribution cable explosion-proof hoses ：
1. Only use unarmored PVC and cross-linked polyethylene cables, excluding other types of cables. If other types of cables are selected in the engineering design, the outer diameter of these cables should be verified to match the protective hose and its rubber gasket or the rubber gasket in the explosion-proof motor junction box.
2. When using aluminum core cables, there should be reliable copper-aluminum transition joints.
3. In explosion-hazardous areas, the cross-section of the power cable to the motor is a copper core cable 2.5m/m2 and above,
4. armored cables do not need to use protective hoses and should be directly introduced into the explosion-proof motor junction box. The allowable gap error between the outer diameter of the cable and the inner diameter of the rubber gasket in the junction box is 1 mm.
5. The connection method between the explosion-proof hose and the explosion-proof motor can be that the cable diameter is introduced into the explosion-proof motor through an underground protective pipe, or it can be introduced into the motor from above through an overhead cable bridge. Note: Galvanized welded steel pipes for low-pressure fluid transportation should be used in explosion-hazardous areas, and the model and specifications of the protective steel pipes should be selected according to the fact that the inner diameter of the protective steel pipe is not less than 1.5 times the outer diameter of the cable.
Fax: 021-67690505
Address: 678 Tongli Road, jiuting town, Songjiang District, Shanghai
