With its exceptional chemical resistance and superior mechanical properties, stainless steel is a popular choice of material for many industrial applications. It is hygienic, it can withstand harsh conditions, and it works well in a variety of environments. From chemical and pharmaceutical manufacturing to food and beverage applications, stainless steel is an ideal material for many industrial tanks. If your company relies on stainless steel tanks, it’s important to understand how undiffused and diffused light affect this highly regarded material.
Maintaining Your Tank Systems
Regular inspections and thorough cleanings are essential to the upkeep of stainless steel tanks, ensuring that they remain in good condition and have long lifespans. After each use and cleaning, tanks must be inspected to ensure that no contaminants remain within the structure. This maintenance prevents costly and stressful issues, including system blockages, fluid contamination, system leakage, equipment malfunction, and unplanned shutdowns.
During these inspections and cleanings, high-quality lighting that ensures visibility is indispensable. Without it, operators wouldn’t be able to fully see tanks’ interiors and determine if any contaminants were present. But are you better off choosing undiffused or diffused lighting?
Undiffused vs. Diffused Lighting
Because it is more concentrated and direct, undiffused lighting can expose many surface imperfections on stainless steel tanks. Diffused lighting, on the other hand, has less variability when it comes to the intensity of reflected light, making it advantageous for sight-based applications. So, if you’re using a sight glass to monitor your tank systems, diffused lighting is preferred.
The type of lightbulb you choose may impact whether you have undiffused or diffused lighting. Should you go with a halogen or an LED light?
The Issues Presented by LED Lighting
For many years, halogens were the go-to lighting product for sight glass illumination – and they still work well in many applications. Halogen lights are valued for their low cost, accessibility, and versatility in regard to sight glass applications. However, they do present some significant disadvantages: low energy efficiency, eye fatigue for operators, short bulb life, and easily damaged filaments. If halogens suit your needs, they’re still a great option. However, many people choose to upgrade to light emitting diodes (LEDs), which are becoming more and more common.
Why are LEDs preferred? They’re brighter, produce less heat, and consume less power when compared to halogen lights. However, LEDs can present complications as well.
Because LEDs produce undiffused light, they can reveal surface imperfections on stainless steel tanks. These imperfections can impact the visual analysis during an inspection – even when the analysis is being conducted by an experienced, highly trained operator. This is partially due to the small size of LED lights, which causes them to produce “hard light,” or light that causes shadowing and masking. These lighting effects exaggerate scratches and other surface imperfections on stainless steel. Furthermore, LED lights produce spectral light, which means the reflected light is dependent on the angle of the light source and the angle of the viewer to the surface. Due to this spectral light, surface flaws that are perpendicular to the light source will appear brighter than the surrounding material.
For these reasons, LED lights can interfere with the visual analysis of stainless steel tanks. As the use of LED lighting has increased, the number of false detections of contaminants has increased as well.
An Analysis of the Effects of Undiffused and Diffused Light on Stainless Steel
Through light analysis, our parent company, L.J. Star, investigated how undiffused and diffused light affects stainless steel. Their team photographed the illumination of both types of light on a piece of stainless steel that had been polished with an Ra of less than 20µIn (0.5µ). To ensure the tests would produce accurate and reliable data, they standardized several elements: the intensity of the light, the position of the stainless steel, and the camera settings.
The analysis of the photographs was not difficult due to the sharp contrast between the two; even a novice could see the distinct differences. When illuminated by the undiffused light, the stainless steel appeared dark and showed numerous scratches. When illuminated by diffused light, the stainless steel appeared bright and had a mirror-like finish. To learn more about the analysis, view L.J. Star’s white paper Analysis of Undiffused and Diffused Light on Stainless Steel.
The results of this analysis are undeniably frustrating. Despite their high efficiency and other valuable capabilities, LED lights produce less accurate inspections due to the fact that they emit undiffused light. Do owners of stainless steel tanks have to choose between highly efficient lightbulbs and accurate inspections? Thankfully, no.
A New Solution to This Frustrating Conundrum
Due to their superior capabilities, LED lights are still preferred over halogen lights. To correct the visual issues they produce when used with stainless steel (while retaining their positive properties), L.J. Star equips LED lights with a diffuser. It’s an easy and effective solution to this persistent problem.
A translucent or semi-transparent cover that forces light to spread out or scatter, a diffuser allows you to transform LEDs’ undiffused light into diffused light. Using a diffuser, you can control the brightness of a light and cause it to emit a softer light relative to the lamp being used. This is extremely valuable in industrial sight glass applications, as the diffused light will ensure that the intensity of any light reflected by the stainless steel reaches more acceptable levels between the imperfections and the rest of the material. In addition, it will eliminate shadowing and masking by making the light source relatively large when compared to the surface features.
The right diffuser can help eliminate the issues presented by LED lights used in stainless steel tanks; however, it’s also important to choose the right LED lights. L.J. Star offers a variety of LED lights for sight glass applications. These environmentally sealed lights are available in explosion-proof designs that will not supply a spark, and they provide bright light, high energy efficiency, and a long lifespan. Plus, they have low maintenance and replacement costs. Available in bulbs producing up to 3,000 lumens, L.J. Star’s LED lights can illuminate even the trickiest applications with ease, and their energy efficiency ensures low costs so that you can retain high margins.
If you have questions about what to look for when shopping for tank components, look no further than the experts at Tank Components Industries. Above all, we strive to be your one-stop shop for all things related to the manufacturing of ASME and non-ASME vessel components. We offer the manufacturing and market expertise that fabricators need to produce the highest quality stainless steel tanks. Whether you’re looking for tank heads and cylinders or ferrules, caps, and other sanitary fittings, we manufacture it all in-house with strict ASME standard compliance. Reach out for a free quote today.