The use of explosion-proof lighting in the oil and gas industry

I. Oil and gas pipeline project selection and the use of explosion-proof lighting phenomenon

Explosion-proof lamps and lanterns used in oil and gas pipeline engineering projects are classified into explosion-proof and lighting according to their functions. Because of its dual characteristics of explosion-proof and lighting, it must be implemented in accordance with the corresponding specifications when installing and selecting.

1. High-pressure gas discharge lamp is required to be installed in the lamp when designing the type-increasing safety explosion-proof lamp

With the advent of new light sources such as electrodeless lights and LED lights, some users often require new light sources such as electrodeless lamps and LEDs when selecting models. Article 5.3.1 of GB3836.3-2010 clearly states: “The light source shall be one of the following types of light sources: a single pin without initiators (Fa6) conforming to GB/T 1406.1-2008; G5 with GB18774-2002 Or G13 tube type double pin fluorescent lamp, the pin is made of brass, the lamp cap and the lamp holder meet the requirements of 5.3.3, such lamp should be connected to start and run without cathode preheating circuit; in line with GB/T10681-2009 and GB14196 .1-2008 General-purpose incandescent incandescent lamps.” Obviously, high-pressure gas discharge lamps, electrodeless lamps, and LEDs do not meet the above requirements. With the deepening of the understanding of explosion protection standards by design institutes and users, such phenomena have rarely occurred.

2. The supplier has over-promoted the protection level of its products to IPX7 flood prevention, resulting in some users often require that the degree of protection of the lamps also reach IPX7

The relevant provisions in GB4208-2008 clearly stipulate that IPX6 is the highest degree of protection for outdoor use, and the use of IPX7/IPX8 is limited to flood prevention/anti-submarine diving, unless the product that identifies IPX6/IPX7 can be used outdoors and submerged.

3. Some users are not strict

Some users do not have strict requirements for the installation of explosion-proof lighting fixtures, and they often think that the factory-installed lighting products can meet the explosion-proof requirements. Does not know that explosion protection is a systematic project, not only must be installed in strict accordance with the requirements of lamps, but also attach importance to the installation of lighting related to the pipeline, interface, etc. meet the explosion-proof requirements. Once there is a problem in one of the links, the entire explosion protection system will fail, and the explosion-proof lighting will not be able to perform its own explosion-proof function.

4 do not understand the limited breathing lamps

Restricted breathing luminaires are new types of products that have been developed in recent years. Because some users do not understand the principle of explosion protection, users do not recognize this type of explosion protection. If the user understands the principle of explosion-proof and the use requirements, there will be a lot of room for the development of breathing-limited lamps.

Second, the selection of explosion-proof lighting

Explosion-proof lamps used in hazardous environments in oil and gas pipeline projects can be divided into explosion-proof, increased safety, intrinsically safe, and restricted-breathing types. Since intrinsically safe types are less involved, the article mainly discusses fixed lamps for factories. .

1. Explosion-proof lamps

The flameproof lamps and lanterns mainly rely on the strength of the product shell and the gap between the bonding surfaces to prevent the flames generated by the explosion in the lamp from spreading to the surrounding dangerous environment, thereby achieving the purpose of explosion protection. The flameproof luminaire structure includes a pure flameproof structure, and a composite explosion-proof structure in which the light source cavity is a flameproof type and the connection box cavity is an increased safety type. Because it has no restrictions on the interior light source (except for low-pressure sodium lamps, because it is not allowed to use in dangerous places), it can be used in hazardous areas in Zone 1 and Zone 2, so it is the most widely used.

Due to the influence of the gap between the flameproof lamp and the joint surface, the protection must be considered when designing, and most of the explosion-proof lamps are used outdoors or in high-humidity applications and must have high protection performance. Therefore, when selecting a type, be sure to specify the protection level requirements and consider the protection requirements. For example, a higher water stop is provided and a seal ring is provided on the explosion-proof surface.

2. Increased safety explosion-proof lamps

Increased safety explosion-proof lamps and lanterns refers to the internal electrical components to increase the safety factor at the same time, increase the protection of the shell to achieve the purpose of explosion-proof. The built-in light source has a variety of restrictions. From the current standards, the light sources that are allowed to be installed in the booster cavity include a single pin fluorescent lamp, a double pin fluorescent lamp, an incandescent lamp, and a self-ballasted mercury lamp.

The relevant provisions in GB3836.15 stipulate that the increased safety lighting fixtures that are only allowed in Zone 1 are single-pin fluorescent lamps. According to the principle of increased safety type single-foot fluorescent lamps, domestic explosion-proof manufacturers short the fluorescent lamp bases of the two legs and then improve the electronic ballasts so that they have protection functions in the case of short circuit, open circuit, open circuit, etc., and can achieve no Warm up to start, making it another fluorescent lamp that can be used in Zone 1. In view of the explosion-proof principle of the increased-safety type lamps, which increases the safety factor of the electrical components, the increased-safety type lamps are only allowed to be used in Zone 2. Only the specially treated single- and double-foot fluorescent lamps can be used in Zone 1. The relevant provisions in GB3836.15 stipulate that the increased safety equipment with exposed live parts shall have at least IP54 degree of protection. In general, the increased safety explosion-proof lamps have IP65 protection rating and are used in outdoor or high humidity locations.

3. Restrictive breathing lamps

Restrictive breathing luminaires are luminaires that have a shell that restricts the entry of gases, vapors and mists. In other words, a breathing-limited luminaire is a luminaire product with a special housing that increases the ability of the housing to restrict the entry of gases, vapours and mists so that hazardous substances do not enter the luminaire in a short time. It is Explosion-proof lamps designed for use in hazardous environments in Zone 2. Since the main source of hazards for restrictive breathing lamps is the limited breathing capacity of the outer shell and the appearance of the product, the determination of the maximum surface temperature during the inspection is the selection of the surface of the lamp body, which is the same as the flameproof products. The most important advantage of the increased safety lighting is that the measurement of the temperature group is the same as the flameproof type, and the location of use is the same as that of the increased safety type (except for fluorescent lamps with special treatment).

In summary, the limited breathing lamp is to achieve the explosion-proof purpose through the good sealing of the shell to limit the intrusion of explosive gas, steam or mist into the lamp body; the explosion-proof lamp is to use the structure and high strength of the joint of the lamp shell. The purpose of the explosion-proof is to increase the safety of the lamp by increasing the safety of the lamp itself. Each of the three types of lamps has different characteristics. The use ranges of the three kinds of lamps are listed in Table 1.

Table 1 The use of three types of lamps

Type Flameproof Increased Safety Increased Safety Fluorescent Lamp Restricted Respiratory Explosion Hazard Zones Zone 0 Zone 1 Zone 2 Zone x√√ x√ x√√ x√√ x√ x√ x× All light sources except low pressure sodium lamps Incandescent lamps, self-powered Mercury Lamp Single/Double Fluorescent Lamps All Light Sources except Low Pressure Sodium Lamps

The types of explosion-proof lighting are different, and have their own characteristics. According to the selection points, temperature groups, and built-in light source types of flameproof, increased safety, and restricted breathing types, they are summarized and compared (see Table 2). Column).

Table 2 Comparison of the performance of three types of lamps

Type Usable Hazardous Area Temperature Group Used Light Source Remarks Flameproof Type 1 Zone 2 Zone Increased Safety Type Increased Safety Fluorescent Lamp Restricted Breath Type 2 Zone 1 Zone 2 Zone 2 Zone 2 High temperature group, low power or cold Light source up to T5/T6 temperature group is lower, generally does not exceed T4 temperature group is lower, generally does not exceed T4 temperature group is higher, low power or cold light source can reach all light sources except T5/T6 low pressure sodium lamp Incandescent lamps, self-ballast lamps, single-leg/double-featured fluorescent lamps, except for low-pressure sodium lamps, all light source transparent parts are thick and need to reach a certain intensity. Transparent parts can meet the corresponding protection class requirements as long as the corresponding protection class requirements are met. Transparency requirements lower than first and second

4. The choice of light source

The selection of the light source is mainly selected according to the characteristics of different light sources, combined with the actual conditions of the scene and the lighting standard. At present, the types of light sources used in petrochemical hazardous locations include the following: metal halide lamps, high-pressure sodium lamps, fluorescent lamps (including energy-saving lamps), incandescent lamps, electrodeless lamps, and LED lamps. The incandescent lamp is a high-energy light source, which has gradually been eliminated. Each type of light source has its own characteristics and usage restrictions. The characteristics and application places of several commonly used light sources are summarized in Table 3.

Table 3 Characteristics and application places of several common light sources

Types of incandescent fluorescent lamps Halogen lamps are used in high-energy light sources and are gradually being phased out. They are mainly used in places where frequent switching is required. Power is limited. Generally, the maximum single-tube power is 36 watts (40 watts), and its light is soft. Dizziness, mainly used for indoor and office power, can be used for higher plant lighting; low power can be used in the installation area of ​​the guardrail type high pressure sodium lamp is mainly used for outdoor lighting (such as street lights, pole lights, square Flood lighting, etc.) Electrodeless lamp features low cost; Instant start; Color rendering 100; No electromagnetic interference, low luminous efficiency; Average life expectancy is only 1 000 hours higher luminous efficiency; With electronic ballast can be activated instantaneously; Average life can be Up to 10 000 hours; need to bring ballasts; soft light and high luminous efficiency; average life expectancy of up to 10,000 hours or more; normal color rendering; need to be equipped with ballasts and other electrical accessories; poor hot start performance; 8 to 10 minutes for high light efficiency; average life expectancy of more than 20,000 hours; poor color rendering; need to include ballasts and other electrical accessories; poor hot start performance; Dynamic time is 10 to 15 minutes; yellow light, high fog-light efficiency; average life expectancy of up to 60,000 hours or more; good color rendering; high frequency generator required; instant start-up; initial investment cost High LED lighting effect; average life expectancy of up to 50,000 hours or more; good color rendering; need to have a constant current/constant voltage source; can be started instantaneously; high initial investment cost; single-side light emission, high lamp efficiency Soft, long life expectancy; suitable for places that are inconvenient to replace and energy-saving renovation; because of its limited power (the current maximum power of explosion-proof LED lights is 200 watts), it is generally not suitable for high-large factory lighting LED lights without lamp holders. Suitable for places with large vibration; cold light source, can be used in places sensitive to temperature; color temperature is adjustable, can be used as street lights and square floodlights; due to its limited power (the current maximum power of explosion-proof LED lights is 200 watts) , generally does not apply to the lighting of tall plants

5. Others

The selection of lamps and lanterns in addition to explosion-proof forms and light sources, there are other requirements. For example, installation methods, installation locations, protection requirements, corrosion requirements, and light distribution requirements.

Third, the installation of explosion-proof lighting

The installation of explosion-proof lighting fixtures is related to the safety of the entire explosion-proof system. It is an indispensable link for long-term safe, reliable and efficient operation of explosion-proof lighting fixtures and should be given full attention. The installation of explosion-proof lighting fixtures should be strictly in accordance with the requirements of GB3836.15 and GB5008.

First, the on-site installation personnel must undergo professional training and obtain the qualification certificate for explosion-proof electrical installation before they can be installed and constructed.

Secondly, before installation, the explosion-proof luminaire operating instructions must be read in detail to clarify the meaning of all product identification contents.

Third, the explosion-proof lamps must be installed in strict accordance with the requirements specified in the product's operating instructions. For example, some lamps have designated mounting positions, and the lamps are installed with angle requirements.

Fourth, explosion-proof lamps and lanterns should be installed in places with less danger. They can be installed in non-hazardous areas and not in dangerous areas. They can be installed in areas not in area 1 and can be placed in areas 1. Zone 0.

Fifth, installation should consider corrosion, high temperature and other factors, try to stay away from hot spots and areas with high corrosiveness. If it can not be avoided, appropriate protective measures should be taken.

Sixth, the installation should avoid rain directly flushing the flameproof surface, reduce the water pressure, and reduce the flooding probability of the lamp.

Seventh, according to the provisions of Article 10.1 of GB3836.15, attention should be paid to avoiding the distance between the flameproof surface and solid obstacles (such as steel frames, walls, mounting plates, pipes, or other electrical equipment) during installation.

Eighth, when opening the lamp for wiring or installing the light source, attention should be paid to the protection of the explosion-proof surface; no grit, etc., or bumping is allowed on the flameproof surface. When installing, it is best to apply anti-rust grease that meets the standards ( Such as 204-I type replacement rust preventive oil).

Ninth, select the appropriate light source type and power in strict accordance with the relevant information in the lamp nameplate and the manual. It is strictly prohibited to change the light source type or power without authorization.

Tenth, the cable should be selected at the entrance of the lamp with a suitable outer diameter so that it meets the requirements for the over-range of the rubber band at the connection port and achieves the purpose of explosion protection and protection.

Eleventh, the internal wiring terminals of the lamp can only be connected with cables with a diameter of 2.5 mm 2 or less. If the cable diameter is too large, the internal terminals of the lamp will not be pressed tightly. If the cable is used inside an increase chamber, it may produce Dangerously lit sparks.

Twelfth, the wiring system of the lamps and lanterns should meet the requirements of the corresponding explosion-proof standards. It is forbidden to cancel the rubber cable directly over the cable.

Thirteenth, when the cable passes through the sealing ring, there should be a certain margin, generally should be more than about 8 mm in length of the sealing ring.