According to recent statistics, natural gas is ranked as the second most consumed energy source in the United States. When converting natural gas into mechanical energy, power plants incorporate gas turbines. The use of gas turbines is widely accepted in power-generating technologies.
Given the ever-increasing need for energy applications, gas turbines require scheduled maintenance. For gas turbines to work at an optimum level, they require regular inspection. Base load, peak load, trips, and types of fuel used are among the many factors affecting the maintenance interval of a gas turbine.
Utilizing a less intrusive method of gas turbine inspection is ideal, since gas turbine components operate under extremely high temperatures. The borescope inspection of a gas turbine allows inspectors to examine tiny details without dismantling the object itself. This article offers you a brief guide on the different types of borescopes.
1. Rigid Borescopes
Just as the name suggests, rigid borescopes are non-flexible gas turbine inspection scopes. Rigid borescopes are optical devices that allow inspectors to access remote areas of the object. Generally, they have a hollow tube, eyepiece, light source, and relay lenses.
Rigid borescopes are popular among manufacturers since they have high-quality imaging. They are much simpler in design and utilize a lens system to relay the image from the objective to the relay lens. The depiction can be viewed through an eyepiece or connected to an adapter.
With their straightforward design, rigid borescopes are easy to use. Professional inspectors use this unique borescope to identify imperfections like cracks. When conducting borescope inspection services on the straight pipes and engine cylinders, inspectors prefer using rigid borescopes.
2. Flexible Borescopes
These borescopes are more versatile compared to the rigid borescopes. During gas turbine inspection, flexible borescopes are used to examine curvy pipes, ducts, and vents. Flexible borescopes use optic fiber, rather than lenses, to transmit an image to the eyepiece.
The fiber optics used makes the tube flexible, versatile, and economical. In a borescope inspection where both the rigid and flexible are required, the inspector could use the adjustable unit. A gas turbine inspector can access both straight and curvy lines using a flexible borescope.
Compared to traditional models, flexible borescopes cover distant areas and greater depths with detail and accuracy. Due to their flexibility, they have a high degree of movement as they can be bent and tilted.
A fiberscope utilizes optical fiber to transmit an image from the end of a flexible tube to a viewer’s eyepiece. Fiber optic technology facilitates for flexible gas turbine inspection. It can bend into areas that are inaccessible with the rigid borescope.
Fiberscope consists of the insertion, control section, and eyepiece. The insertion section consists of a flexible tube containing optical fiber. Additionally, the control section has a light source connected to a light guide.
Images displayed by a fiberscope are unique in that each fiber can relay only one color or similar colors. The transmitted image is of comparable quality to a night vision camera image.
4. Video Borescope
Videoscopes resemble fiberscopes in both appearance and operation. A videoscope is an advanced borescope that uses image sensors to relay images to an operator. It has a charged coupled device (CCD) located at the tip of the borescope.
The CCD relays the image electronically through the flexible scope to the camera control unit (CCU). Videoscopes have made it possible for inspectors to store any borescope inspection report for future reference.
The viewing angle of a videoscope and field of view are specified in degrees. Typically, videoscopes are used to inspect crevices of turbines, pipes, buildings, pumps, and valves.
Regardless of the type of borescope used during gas turbine inspection, viewers get a real-time view of vital inspection areas. Before settling for a borescope, consider the quality of the device and its application. You need the right borescope to detect faulty parts. When looking to purchase a borescope, seek advice from your local turbine inspectors.