Borescope Fuel Tank Inspections

by | Mar 1, 2022 | Blog

Fuel tanks are found in various sizes and applications.   Of course, we think of our automobile fuel tanks frequently as that is the tank, we have the most experience with.  But fuel tanks are present not only in residential applications such as lawnmowers, weed eaters and tractors but also in industrial and aerospace applications.   Every combustion engine offers some sort of fuel tank of varying size and configuration.  Fuel tank inspections are not something that is required often, but when it is required, you want to make sure that you have the right tool for the job.

Because the tank, (whether it be gasoline or diesel fuel) hold a combustible liquid and gas the area is considered a hazardous inspection area or explosive environment.    Whether the tank still has measurable liquid in the tank or just residual fuel and fumes the area is still considered hazardous and requires specialized and certified borescopes to complete the inspection.

Why would someone need to inspect a fuel tank?   There are many reasons.  Perhaps there is physical contamination that needs to be identified, mechanical parts or valves that need to be inspection or for police and customs inspection professionals there is a need to search for contraband.  In addition, there could be tank cracks that need to be identified.  Of course, cracks on the outside of a tank are much easier to inspect and document.  These tanks could contain other hazardous and explosive chemicals that are not necessary used in combustion engines, but still need to be inspected internally.

Customarily there are 4 main reasons to inspect a fuel tank:

  1. Confirm the Stability and Performance of the tank: Older fuel tanks, especially those made of metal, inherently are at greater risk of breaking down and being compromised.  Borescope tank inspections can identify internal issues that may warrant corrective action or replacement.
  2. Inspect the inside walls of synthetically lined tanks:   A number of modern fuel tanks are lined with protective coatings to prevent leakage.  Using a certified borescope for explosive environments allows you to visually inspect the entire lined area of a fuel tank.
  3. Identify reasons for clogs with the fuel filter: Many modern fuel tanks in automobiles offer a non-serviceable fuel filter.  A clogged fuel filter can result in lost performance as well as trouble starting, acceleration issues, engine sputtering as well as engine misfires.  The gas tank borescope will allow you to enter the tank and inspect the in tank fuel filter.
  4. Identify contamination and debris inside the tank: In time, debris can enter the fuel tank. Debris such as dust, dirt, sand and other sediments can be found inside the fuel tank.  A fuel tank full of dirt and contamination will make it hard for the fuel pump to push the fuel into the engine at the first start.

For most car gas tank inspections, a borescope with 2 meters (6.6 feet) is sufficient.  This length is long enough to enter the supply path from outside the car and down into the fuel tank.   Most all of the gas tank borescopes will provide at least 2-way articulation and most will offer 4 way articulation.   This will allow you to manipulate the tip of the probe to scan the entire area of the gas tank.

Airplane fuel tank inspection, helicopter fuel tank inspections and automotive fuel tank inspections are most common.  Even though many of the fuel tank manufactures have moved to fuel tank with a plastic or synthetic configuration there is still a need to inspect the fuel tank.  Usually, these smaller fuel tanks can be inspected with a smaller diameter borescope (6-8mm) with articulation.  Usually these inspection are carried out with a Certified Explosion Proof Borescope that offers at minimum Class 1 Division 2 borescope rating.   These Hazardous Inspection Cameras are available in diameters in 4, 6 or 8mm diameters with various lengths.  The borescope fuel tank inspection is used for maintenance, repairs, contraband inspection or for law enforcement training.

Of course, before you start any inspection in a hazardous environment you should consult with your in-house Health and Safety department to determine what precautions need to be taken and whether or not your will be required to have a Confined Space Permit or any required PPE (Personal Protective Equipment).  OSHA offers specific guidelines when working with Confined Spaces or functions that could expose someone to harmful chemicals.   For some of these tasks there is a certification process that must be obtained prior to attempting these functions.   Specifically, the Confined Space Permit will require that there is a designated Supervisor as well as attendants that can successfully perform rescue operations in the event that there is a failure or injury during the inspection process.   The entry will also require that you confirm air quality with an air quality monitor.  The only way to safely detect a hazardous atmosphere is with a “calibrated direct reading instrument” as described in OSHA’s confined space standard 29 CFR 1910.146. A gas monitor is not the only component of an effective gas detection program.

The actual tanks to inspect could range in size form ounces to hundreds of gallons. Depending on the size of the container, the entry point for the camera and what is target inspection area, you may choose from a range of inspection devices.

For the smaller passenger vehicle, tractor or commercial road vehicles the smaller diameter borescope will typically work well.   We do recommend that you also source a gas tank flap holder.   This device is used primary by law enforcement and Customs Agents and allows a channel to introduce the borescope probe into the gas tank.   This prevents the gas tank flap from crimping the probe and causing damage.  The gas tank borescope will allow you to see into the tank pipe that supplies fuel to the tank and the inside of the tank that is not visible to the human eye.  There are Class I Div II videoscope as well as a Class I Div II fiberscope available to perform this inspection.   The explosion proof videoscope is usually more popular and convenient as it provides on board capabilities to take pictures and record videos.   The hazardous inspection fiberscope does provide very good imaging but does not easily provide the ability to take pictures and videos of the gas tank inspection.

For larger tanks you may require an inspection camera with a larger diameter.   Typically larger diameters will provide greater output as the design and configuration allow for more lighting to be supplied.   The P374 is a Certified Class 0 Inspection camera system.  The P374 Camera is designed mainly for pipes with diameters greater than 2 inches.   The P374 Intrinsically Safe inspection camera is available with 200 feet of working length and 1 inch diameter camera head.  For use with tank inspection we recommend a non-conductive pole with the Pole Cat accessory to allow you to view the sides of the tank.  The Pole Cat attaches to the camera section and allow you to fix the camera head to any angle.   We typically see the need for the P374 Inspection Camera requirement for in ground storage fuel tanks, specifically at gas stations.

P374 Intrinsically Safe Color Video Inspection System

Not all storage tanks, fuel tanks, chemical tanks or containers are designed the same or inspected the same but the ultimate goal of inspections is to ensure safety and serviceable conditions at current levels as well as for the future.

Individual situations may vary, but safety inspection for an explosive environment will generally include the following things:

  • Emergency Procedures. There should be emergency procedures for fire, spillage, accidents an equipment failure.
  • Emergency Numbers
  • Emergency Stop or Cut off valves
  • PPE (Personal Protective Equipment)
  • Safety Equipment.
  • Site plan and Risk assessment.

Contact your Health and Safety Professional for safety precautions and requirements.

The Certified Explosive Environment Borescopes typically offer a higher cost of initial ownership.  If your specific borescope inspection does not require this type of borescope inspection camera you may choose from our standard industrial borescope line.