Explosion-proof safety: Explosion-proof safety of common equipment

First, there are explosion-proof safety hazards in the selection of equipment

1. Use common electrical products in explosion hazardous locations.

2. Use coal mine underground electrical equipment at the factory site.

3. Use explosion-proof electrical equipment for gas environment in explosive dust environment.

4 , from the appearance of the product structure, looks like explosion-proof products. However, these products have neither product nameplates nor explosion-proof signs and product certification information (eg, explosion-proof certificate numbers). At the same time, it is unable to provide three products without the explosion-proof certificate of the product.

5 , from the appearance of the product structure, suspected of explosion-proof products. However, only the EX general-purpose mark and the explosion-proof mark are included in the brand name of these products , but there is no product certification information (for example, the explosion-proof certification number). Can not check, confirm whether the product has been tested and certified by a national authorized testing agency.

6 , determined by the professional testing personnel as ordinary products, but hit the explosion-proof information brand name fake and shoddy products.

7. In Class IIC hazardous locations, use Class IIB explosion-proof products.

8 , equipment selection requirements for the T4 temperature group, the actual selection of temperature group T1 explosion-proof products.

Second, explosion-proof electrical products have their own security risks

1. The outer shell of explosion-proof electrical products is damaged.

2. Nameplates of explosion-proof electrical products are missing or obscure.

3 , Explosion-proof increase safety composite explosion-proof cavity and wiring chamber isolation seal packing does not meet the requirements.

III. Explosion-proof safety hazards in the installation of electrical equipment

1 , cable introduction does not meet the requirements.

2 , excess line into the hole with plastic mud plug / plastic plug / unblocked.

3 , fastening bolts are inconsistent, missing, loose, rust, missing bombs, flat pads.

4 , flameproof electrical equipment cable or wire inlet and pipe directly connected.

5. The flexible tube is directly connected to the equipment and the cable introduction device is not installed.

6. The cable entry device installed in the explosion-proof equipment is inconsistent with the explosion-proof type.

7. The flameproof joint gap of explosion-proof equipment is too large.

8 , flameproof joint corrosion.

9. The flameproof joint between the lid and the box is coated or padded.

10. The independent explosion-proof chambers conduct each other without isolation and sealing measures.

11. The distance between the flameproof joint and the solid obstacle is too small.

12. Aging of the box or aging of the sealing gasket. The gap becomes larger and the protection level is not up to the requirement.

13. Increased safety equipment has been replaced or added without approval.

14. The bending of the anti-explosion interference tube is too small, the aging of the interference tube, and the rubber sheath is damaged.

IV. Problems in the laying of cable lines

1 , cable changes, damage.

2. Cables are directly connected in hazardous locations.

3 , the wire is twisted in the increased safety wiring.

4 , in the threading box wiring.

5. No isolation and sealing measures are taken when the cable passes through different areas.

6 , armored cable is not equipped with armored cable introduction device.

7 , armored cable armor exposed.

8. The unused cable ends shall be disposed in hazardous places. Unused bare copper conductors shall be placed in the increased safety junction box without being fixed or insulated.

V. Grounding and equipotential bonding problems

1 , the outer ground is not connected.

2 , the external grounding line in series, the cable bridge and the liquid conveying pipeline equipotential connection problems.

3 , outside the grounding line is less than 4mm ? .

4 , external ground bolt corrosion.

VI. Inspection and maintenance

1 , Explosion-proof electrical equipment inspection and maintenance

For the use of explosion-proof electrical equipment, it is necessary to implement daily inspection and maintenance and regular professional inspection and inspection systems. The problems reflected in the typical cases cited in the appeals are the focus of routine inspections and maintenance, and the specific contents will not be repeated.

During inspection and maintenance, explosion-proof electrical equipment was found to be degraded or failed due to external force damage, atmospheric corrosion, chemical corrosion, mechanical wear, and natural aging. Should be overhauled. Inspection of explosion-proof electrical equipment shall be carried out in accordance with GB3836.13-2013 . The explosion-proof performance that can not be restored to the original grade after overhaul can be dealt with according to the following principles according to actual technical performance:

a , reduce the use of explosion-proof grades ;

b , reduced to non-explosion-proof electrical equipment.

2. Explosion-proof performance of explosion-proof electrical equipment fails

When the explosion-proof electrical equipment structure is found during maintenance, the parameters change, and it is inconsistent with the original explosion-proof type and design and cannot be repaired, that is, it is judged to be invalid, and it is quickly deactivated and replaced. For example:

a . The enclosure of flameproof electrical equipment can not be repaired due to serious deformation;

b . The flameproof surface is seriously damaged and cannot be repaired;

c . Flameproof gap exceeds national standards and cannot be restored;

d . Cracking of explosion-proof electrical equipment enclosures does not meet the requirements of the original explosion-proof type.

Conclusion

1. The appeal issue is just a typical example of explosion hazards common to explosion hazardous equipment.

2. For the danger of explosion, in the past a long period of time, everyone mainly focused on hazardous chemicals, or focused on explosive gas atmospheres; on flammable dust, there was less concern about the explosion hazard of fiber materials, in fact, flammable dust Once the fiber material explodes, it is no less harmful than a gas explosion. For example, in the 1980s, the flax fiber explosion in the Harbin flax factory, the metal dust explosion in Kunshan last year, and the starch dust explosion in Xinbei, Taiwan all caused serious consequences.

3. For most powder-related companies in China, the security situation is still not optimistic. Explosion-proof safety hazards still exist in large numbers. For example: the use of ordinary electrical equipment in dust explosion hazardous locations, the selection of gas explosion-proof electrical equipment, or the use of dust Explosion-proof electrical equipment and the use of the environment does not match the phenomenon is very common.

4. Due to different industries and different situations, the explosion hazards that exist in explosion hazardous locations are numerous and varied. Due to time constraints, they no longer complain.

5. If the hidden danger exists, an explosion accident may occur at any time. What should I do?

a . Before the explosion-proof electrical equipment with serious failure of explosion-proof safety performance is completely rectified, it is necessary to strictly monitor the working state of the main device to prevent the occurrence of flammable gas, liquid and dust. Create an explosive atmosphere.

b . Ensure that combustible gas detection alarms and dust detectors installed in explosion hazardous locations are used within the effective period of measurement. Once exceeding the standard or warning, all devices should be immediately stopped for inspection and disposal.

c, according to SAWS released security industry production standards AQ3009-2007 "explosion hazardous area electrical safety regulations," the provisions of clauses 7.1.3 .2, safety testing and inspection agency entrusted with explosion-proof professional qualifications are regularly checked as soon as possible.

d . According to the results of the regular inspections and corresponding rectification proposals, take corrective measures in a timely manner according to the standards and conduct comprehensive and positive rectification.

e . Establish and improve management systems for procurement, installation, acceptance, use, maintenance, overhaul, and retirement of electrical equipment in explosion hazardous locations, and strictly inspect and implement them.

f . In the whole process of engineering design, selection, procurement, installation, commissioning, acceptance, acceptance and operation of explosive environmental equipment, introduce explosion-proof professional inspection / regulatory units, professional agencies undertake explosion-proof professional gate work, and early detection of fire and explosion hazards. Early scientific treatment will eliminate hidden dangers in the embryonic stage and minimize economic loss and personal injury.

The information in this article comes from the Internet and was reorganized and edited by China Rescue Equipment Network.