When you’re inspecting a hazardous environment, such as a Class I Division II or a Zone 0 hazardous area, you need a hazardous environment borescope made especially for such environments.
Inspections of natural gas lines, fuel tanks, and any other inspections where the pipes could contain explosive material are extremely sensitive and need borescopes that are designed not to trigger a reaction or cause damage.
A Hazardous Area is defined by three main criteria, these being:
- The type of hazard (groups)
- The auto-ignition temperature of the hazardous material (temperature or “T” rating)
- The likelihood of the hazard being present in flammable concentrations (zones)
The Type of Hazard
The type of hazard will be in the form of either a gas or vapor or a dust or fiber.
The classification of these hazardous zones is primarily divided into two groups depending on whether it is in a mining or above surface industry. These are defined below:
Group I – electrical equipment for use in mines and underground installations susceptible to firedamp Group II and Group III -electrical equipment for use in surface installations
Groups II & III are further sub-divided depending upon the hazard. Group II gases are grouped together based upon the amount of energy required to ignite the most explosive mixture of the gas with air. Group III dusts are subdivided according to the nature of the explosive atmosphere for which it is intended
Hazardous Location Types:
Class I Locations
According to the NEC, there are three types of hazardous locations. The first type of hazard is one, which is created by the presence of flammable gases or vapors in the air, such as natural gas or gasoline vapor. When these materials are found in the atmosphere, a potential for explosion exists, which could be ignited if an electrical or other source of ignition is present. The Code writers have referred to this first type of hazard as Class I. So, a Class I Hazardous Location is one in which flammable gases or vapors may be present in the air in sufficient quantities to be explosive or ignitable. Some typical Class I locations are:
- Petroleum refineries, and gasoline storage and dispensing areas
- Dry cleaning plants where vapors from cleaning fluids can be present
- Spray finishing areas Hazardous Locations Page 2 OSHA 10 Hour Construction • Aircraft hangars and fuel service areas
- Utility gas plants, and operations involving storage and handling of liquefied petroleum gas or natural gas
All of these are Class I gas or vapor hazardous locations. All require special Class I hazardous location equipment.
Class II Locations
The second type of hazard listed by the National Electrical Code is those areas made hazardous by the presence of combustible dust. These are referred to in the Code as “Class II Locations.” Finely pulverized material, suspended in the atmosphere, can cause as powerful an explosion as one occurring at a petroleum refinery. Some typical Class II locations are:
- Grain elevators; • Flour and feed mills
- Plants that manufacture, use or store magnesium or aluminum powders;
- Producers of plastics, medicines and fireworks;
- Producers of starch or candies;
- Spice-grinding plants, sugar plants and cocoa plants; and
- Coal preparation plants and other carbon handling or processing areas.
Locations where you will need an explosion proof borescope are considered as Class 1 and are places where flammable vapors and gases are present.
A Division II location is classified as such where these ignitable hazards are present in concentration and are handled, processed, or used. They’re kept in closed containers and systems, but there is a chance of these explosives leaking through a rupture or some sort of damage of the container or system that they are present in.
That’s why you need equipment that is intrinsically safe, which means it is designed with an explosion protection technique. Its electrical circuit is what sets it apart from regular equipment. The wiring cannot release enough energy—electrical or thermal, whether in normal or unusual circumstances—to cause an ignition and lead to a potential explosion.
A popular system for Law Enforcement is the Freedom View Borescope model number FVVS680 certified Class I Div II borescope.
Class III Locations
Class III hazardous locations, according to the NEC, are areas where there are Easily ignitable fibers or flying debris present, due to the types of materials being handled, stored, or processed. The fibers and flying debris are not likely to be suspended in the air, but can collect around machinery or on lighting fixtures and where heat, a spark or hot metal can ignite them. Some typical class III locations are:
- Textile mills, cotton gins;
- Cotton seed mills, flax processing plants;
- And other similar Hazardous Locations
The terms of Intrinsically Safe and Explosion Proof are used to describe products destined for use in hazardous or explosive environments. Such products including borescopes and videoscopes are designed and manufactured to prevent a malfunction of normal operation in electrical process equipment from initiating an explosion or fire through ignition of flammable or combustible materials (both liquid and gas) and other measurable matters that may be present in the surrounding hazardous atmosphere.
Main Sources of Ignition
Arcs and sparks produced by the normal operation of equipment, like motor starters, contractors, and switches, can ignite a hazardous location atmosphere.
The high temperatures of some heat producing equipment, such as lamps and lighting fixtures, can ignite flammable atmospheres if they exceed the ignition temperature of the hazardous material. The National Electric Code requires special marking of heat producing equipment with temperatures above 100 C (212aP).
Electrical equipment failure is another way an explosion could be set off. A burn out of a lamp socket or shorting of a terminal could spark a real disaster in a hazardous location.
What Is a Zone 0 Hazardous Location?
Similar to a Class I Division II hazardous area, a Zone 0 hazardous area means that it contains concentrations of combustible gases or materials that have been present in the location for a long and consistent period of time. When working in such areas, intrinsically safe borescopes are essential to avoid any unforeseeable interactions between equipment and volatile materials which could result in an explosion or accident.
What Kinds of Borescopes Can You Use for Hazardous Environments?
There are several different kinds of borescopes that you can use for hazardous environments, depending on the kind of inspection you are attempting to do. A hazardous environment borescope, also known as a hazardous portable inspection camera, can be a vital tool when conducting inspections where there is a safety hazard, such as chances of an explosion from using regular equipment and tools.
Here are the kinds of borescopes that professional prefer using in dangerous environments.
Heat Resistant Borescope
A regular borescope is not suitable for a high temperature environment. The sensors, electrical parts, and the lens used in these borescopes cannot withstand a temperature higher than 176 degrees Fahrenheit. A heat resistant borescope can function in environments where the temperature is as high as 572 degrees Fahrenheit.
Heat resistant borescopes often come with heat sensors that notify you when you are in a temperature that could damage the lens or machinery of the borescope. Both extremely cold and extremely hot temperatures are dangerous for regular borescopes, so having one that is designed to be resistant to heat is essential.
High Temperature borescopes are usually designed with a cooling jacket that utilize air or water to cool the borescope camera. Borescope cameras that are designed to withstand high temperatures and heat allow you to explore a whole new area of hazardous environments which were previously off-limits or risky to inspect.
Water, Oil, and Dust Resistant Borescope
When it comes to this type of borescope it is important to understand the difference between water proof and water resistant. A videoscope camera will have some measure of water and dust resistance which is usually in the IP68 or IP67 rating. These videoscope systems can be exposed to water without issue but are not designed to be submerged into water or other liquids for constant or long durations like a sewer camera is. To be water proof the system must be rated at IP65.
These borescope cameras are flexible, have rechargeable batteries, and can come with probes that are resistant to water and oil submerges, which means they are high pressure borescopes that aren’t affected by the pressure of the liquid.
However, when submerging these borescopes into liquids, make sure you read the user’s manual first and do not exceed the amount of time the camera can safely stay below the surface.
Intrinsically Safe Borescope
An intrinsically safe borescope is made so that its energy, both electrical and thermal remains at a level that doesn’t risk any kind of ignition of the combustible gases and materials present in that environment. These borescopes are great for confined spaces because of the differing sizes of their probes and their portability, making it easier to see inside pipes and engines without a risk of ignition and without having to dismantle the machinery first. At present the only Class 0 Certified Intrinsically Safe Inspection camera is the P374 Camera.
Explosion Proof Borescope
An explosion proof videoscope is a key tool for inspecting environments for military, police, and forensic purposes, as well as for gas compression, oil and gas industries, aviation industries, etc. The advantage of using an explosion proof borescope is that it removes any sparks and puts them out before they can become a hazard or cause a reaction.
You can inspect locations which were previously avoided in a shorter amount of time and with more accuracy, enhancing the performance of your machinery and catching any problems.
Because the adjustable LED light source is designed with a leached Fiber Optic bundle down to the tip of the explosion proof borescope, with the LED light source in the handle not the tip, these Explosion Proof Video Borescopes provide for safer remote viewing. The Explosive Proof Borescopes that we offer provide 4-way articulation and available in 4, 6 or 8mm diameters. These Explosion Proof Videoscopes are available in various lengths up to 7 meters with full articulation.
There are certified Class 1 Div 2 fiberscopes as well. These have had a long history with law enforcement searching for contraband during a gas tank inspection. Systems such as the FreedomView borescope off a unique design with an Electrostatic Discharge (ESD) Common Point Ground for added safety. This device grounds the fiberscope system to the inspection area as the inspection camera is used inside the gas tank or other combustible environments.
Final Words
To have an easier time with your remote visual inspection in any environment, even locations that contain combustible gases and volatile materials, you should invest in a hazardous environment borescope.
These borescopes come with different probes that allow for extra navigation, distance covered, and higher quality images. What’s more, they come with portable batteries and are highly flexible, which makes them a convenient option to inspect even the tiniest of components and pipes and detect minor damages or changes effectively and clearly.
With a videoscope designed to be resistant to dangerous environments, high pressure, temperature, and explosions, you don’t have to take your machinery apart in order to do the inspections. You can simply select a video borescope probe that is appropriate for the location and get an image that is sent digitally for clearer viewing.
These borescopes are also lightweight, compact, and easy to maneuver, which means that with careful practice and precaution, you can learn to use them efficiently and without a risk of accident or explosion, as long as you are already skilled at using regular borescopes. They also have carry straps to hang around your neck for convenience, especially when working in tight spaces.
You should always rent or purchase your borescopes from reliable and certified retailers, such as USA Borescopes. We have an assortment of hazardous environment videoscopes that are specially designed for inspecting Class I Division II environments in a safe and secure way.
The Explosive environment borescopes can be a significant investment for most companies and if you decide you do not require a non destructive test equipment with these types of fail safe designs you can consider a standard videoscope.
