Gauges & Gauge Glasses 

Gauges & Gauge Glasses: Types & Applications

Introduction

A gauge glass is a transparent tube used to monitor liquid levels in a tank or boiler. A sight glass, also known as a gauge glass, is used to determine the depth of a liquid. When installed in a tank or vessel, it provides a constant readout of the liquid's level.

One way to check the water level in a tank is with a sight glass instrument, which consists of a graduated tube made of toughened glass that is attached to the tank's interior at its base. The sight glass in the picture below is a straightforward method of gauging the contents of an open tank, as the liquid level in the sight glass precisely parallels the tank's actual contents.

Changes in the liquid level in the tank are reflected in the sight glass in a similar fashion. The sight glass can be used to determine how much liquid is in the storage tank.

Different types of gauges & gauge glasses

1. Multifunctional Glass 

These tools incorporate not just the aforementioned capabilities, but also others, such as the ability to remove the sight glass for cleaning and examination.

2. 3D 

This sight glass is similar to a bullseye, except instead of being flat, it protrudes from a tank. It also lets light travel through the oil, making it simpler to spot pollutants, and increases the number of perspectives from which you can examine the oil.

 Most of these can withstand high pressure and high temperatures since they are constructed of glass, acrylic, or polyamide.

3. BS&W Bowls 

Bowls designed to collect sediment and water from the tank's base are called bottom sediment and water (BS&W) bowls. There is a release valve on several of them so that oil samples can be taken for testing.

 These are significantly more compact than their columnar counterparts and can be installed towards the bottom of tanks, where they are more vulnerable to damage.

4. Columnar 

These transparent, vertical tubes are installed on the exterior of storage tanks and provide a more comprehensive view of the oil inside than traditional bullseye sight glasses. 

However, they are more challenging to install, and since they are usually placed near the tanks' bases, they are more likely to sustain damage. 

Also, they have trouble detecting foaming because they draw from the tank's base. When compared to bullseye, the use of columnar Gauges & Gauge Glasses allows for the accurate marking of oil levels in both the running and idled states of a machine. 

Target glasses can only differentiate between the two.

5. Bullseye 

When installing a bullseye Gauges & Gauge Glasses, a hole is drilled into the tank at the ideal oil level. When installed, the sight glass resembles a bolt with a glass head and is threaded into the opening. 

Several models feature a line in the sight glass at the proper oil level for operating machinery. 

A bullseye Gauge Glasses can aid in the detection of foaming in the system. In the presence of water and other impurities, this frequently occurs, allowing you to spot issues before they become catastrophic.

6. Circular Sight Glass Fittings 

Sight glasses, also known as sight windows or view ports, allow for inspection of the contents of a tank or vessel from the outside.

They are made up of two flanges that are bolted together and seal a glass disc with gaskets. Commonly used to check liquid levels and visually validate process steps. 

Pressure vessels, tanks, silos, stirred vessels, separators, pipelines, etc., can all benefit from inspections using this method. 

7. Sight Indicators 

This is a device that is placed in a pipeline to check the flow of a liquid, powder, or gas. A body with a window or windows is what makes up this thing. This method is the most accurate for validating flow's direction, approximate rate, color, and clarity. 

For clean rooms, hospitals, and other sterile environments, Sight Glass producers provide both regular and full-view flow indicators.

8. Metaglass Sight Glass Windows 

The "METAGLAS®" brand of metal fused sight glasses has a sight glass fused into a steel ring. This is because glass and metal have differing expansion coefficients, leading to compressive stress within the glass. The steel ring's mechanized treatment allows for a wide range of potential building solutions.

9. Rectangular Sight Glass Fittings 

Gauge Glasses, which are also known as sight windows or view ports, allow one to see inside a tank or vessel by way of two flanges that are bolted together and seal a glass disc with gaskets.

Most commonly employed for visual inspection of process material and liquid levels as well as verification of process phases. Tanks, stirred vessels, pressure vessels, separators, pipelines, silos, and so on are common places where this technology is put to use.

Applications of gauges & gauge glasses

1. Tanks and Reservoirs 

Gauges & Gauge Glass, also known as sight glass, is an indispensable component of tanks and reservoirs because it allows for quick and easy monitoring of liquid levels. The Red Line variation, designed to be installed between the upper and lower Gauges & Gauge Glass valves, contains a red line that is tinted with white lines to facilitate readings.

2. High and Low pressure boiling 

Gauge Glasses are perfect for liquid measurement in boilers due to their exceptional thermal endurance, great clarity, and consistent operation even at high temperatures.

3. Flow meters 

Gauge Glasses provide precision, safety, and reliability for sectors that need to measure the volume of gas or liquid passing through a device. Industrial flow meters require gauge glasses because of their excellent resilience to chemical and thermal shock.

Things To Consider Before Purchasing Gauges & Gauge Glasses

1. Impact

Materials entrained in process fluids may strike the sight glass window in some operations, such as food processing. If you notice any scratches on your glasses, it's time to get a new pair.

2. Pressure 

All high-pressure applications should employ fused-type sight glasses or cast-type plastic windows to prevent sight glass failure, as was previously mentioned.

3. Abrasion 

Pick a material for the sight glass that won't wear down or become clouded by particles in the fluid being viewed. Sight glasses can be tested for scratches either visually or with the help of ultrasonic technology.

4. Corrosion 

Sight glass windows can grow "cloudy" over time when exposed to certain caustic or acidic chemicals, reducing their transparency. Select a plastic or glass sight glass window that is less likely to corrode in these sorts of applications.

5. Thermal Shock 

When deciding on a material for a sight glass, engineers must keep in mind how the material will react to extreme temperature swings. Since it has a lower coefficient of expansion than regular glass, borosilicate glass can better withstand temperature swings and is hence the material of choice for glass windows. Sight glass windows made of plastic can withstand variations in temperature because of their flexibility.

6. Maximum Operating Temperature 

Regular soda lime sight glass windows and plastic view ports can only be used in environments with temperatures no higher than 300 degrees Fahrenheit. Glasses made of borosilicate or quartz/sapphire must be used above those temperatures.

7. Construction materials

The two most popular metals are carbon steel and stainless steel. For this reason, stainless steel is the industry standard in the pharmaceutical industry due to its superior corrosion resistance.

8. Process fluid 

Before filling a reservoir or tank with fluid, find out what kinds of things it can corrode. If you need a sight glass, one with "excellent" chemical resistance is what you should be on the lookout for.

9. Past Issues

Check to see if there have been any past issues that you need to keep an eye on. Have you ever experienced lubricant contamination due to wear debris? If so, select a sight glass outfitted with a magnetic plug to aid in capturing the debris before proceeding with testing.

Conclusion

Depending on the gasket and clamp union you choose, the maximum temperature and pressure are also different. Sight glasses are vital tools in the process industries, where they are used to inspect tanks and pipelines for fluid and media levels

Sight glasses are a type of specialized instrument that have many applications in the processing industries. This post has provided an overview of sight glasses and how they are used in the pharmaceutical, food and beverage, semiconductor, utility, energy, oil and gas, and wastewater management industries.

FAQs: Gauges & Gauge Glasses

Q. Which type of gauge & gauge glass is commonly used in the laboratory?

Ans. Tubular Gauge Glasses are mostly used in Laboratories for liquid level uses in industrial steam boilers. 

Q. How do Gauges & Gauge Glasses work?

Ans. Gauge glasses, once fitted, function as windows to allow operators to monitor internal activities in a variety of containers, such as tanks, vessels, reactors, and pipes. Gauge glasses are made from either soda lime glass or borosilicate glass because of their durability.

Q. What happens if the Gauge & gauge glass break?

Ans. That way, even if the gauge & gauge glass breaks, the stop ball will keep the water from escaping.

Q. What is the cost of Gauges & Gauges glass?

Ans. The cost of Gauge Glasses is between Rs 900- Rs 2,500 in India.