Tubular Sight Glass
Tubular Sight Glass for Direct Liquid Level Indication in Tanks, Reservoirs, Boilers, and Flowmeters
Tubular sight glass is the clear glass tube used in level gauge assemblies to show liquid level directly and continuously.
It is a practical solution for industrial level monitoring when the user needs a readable liquid column, a stable installation, and a tube that can be matched to pressure, length, end finish, and service condition. The family is commonly available in multiple variants and a wide size range. :contentReference[oaicite:1]{index=1}
Typical Tubular Sight Glass Use
Tank / Reservoir
Tubular Sight Glass
Inspection / Reading
Tubular Sight Glass Forms
Common Tubular Sight Glass Forms for Industrial Level Gauge Service
Buyers usually choose tubular sight glass by visibility style, pressure requirement, and tube construction. The family is commonly supplied in standard, red line, high pressure, heavy wall, and heavy wall red line forms. Typical published size ranges run from 1/2" OD to 1 1/2" OD, with end finishes of cut, ground, or fire polished. Pressure ratings can range from 90 to 600 psi depending on the tube form and the full specification. :contentReference[oaicite:2]{index=2}Redline Tubular Gauge Glass
Redline tubular gauge glass is used when the level needs to be easier to read from a distance or when the liquid is clear and low-contrast. The red stripe improves visibility and makes the level easier to identify in tanks, reservoirs, and low-pressure boiler applications. This form is commonly searched as red line gauge glass, redline gauge glass tube, and redline tubular gauge glass. It is a practical choice for operators who want better visual distinction without changing the basic tubular gauge arrangement. :contentReference[oaicite:4]{index=4} Learn more →High Pressure Tubular Gauge Glass
High pressure tubular gauge glass is used when the level gauge needs to withstand a more demanding pressure condition than a standard tube. It belongs to the same family of tubular gauge glasses that are offered with different end finishes and diameter options, and it is a common fit for industrial systems that need a stronger tube selection while keeping the same basic visual-reading method. Buyers often use search terms such as high pressure gauge glass, high pressure tubular gauge glass, and clear high pressure gauge glass. :contentReference[oaicite:5]{index=5} Learn more →Heavy Wall Tubular Gauge Glass
Heavy wall tubular gauge glass is the strongest tubular glass option in the family and is chosen when pressure margin and heat-shock resistance are more important than cost. This type is described as the highest pressure-rated tubular glass, with very clear optical performance and extra resistance to heat shock. It is commonly available in 5/8" and 3/4" OD versions, with ground ends, and is often searched as heavy wall gauge glass or heavy wall gage glass. :contentReference[oaicite:6]{index=6} Learn more →Heavy Wall Red Line Tubular Gauge Glass
Heavy wall red line tubular gauge glass combines the visibility advantage of the red stripe with the stronger construction of a heavy wall tube. It is useful when an operator wants a readable liquid column and a stronger tube form in the same assembly. This type is frequently selected for demanding service where readability, pressure margin, and durability all matter at the same time. It is a common search phrase for replacement work and custom industrial gauge assemblies. :contentReference[oaicite:7]{index=7} Learn more →Custom Cut Length Tubular Sight Glass
Custom cut length tubular sight glass is used when the standard stock length does not match the customer’s gauge body or installation drawing. Buyers often need a special length, end finish, or diameter match, especially in replacement work for old equipment or OEM assemblies. Standard product literature allows different lengths, diameters, and end finishes to be combined into the final specification, which makes custom cut lengths a practical sourcing option for many industrial projects. :contentReference[oaicite:8]{index=8} Learn more →-
Glass tube
Borosilicate Tubular Gauge Glass
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Glass tube
Borosilicate Tubular Sight Glass
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Glass tube
Heavy Wall Tubular Gauge Glass
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Glass tube
Quartz Glass Tube
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Glass tube
Redline Tubular Gauge Glass
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Glass tube
Transparent Tubular Gauge Glass
Specification Guide
Tubular Sight Glass Specification at a Glance
Use this table to compare the most common tubular sight glass requirements before requesting a quotation. Exact pressure capability depends on the variant, diameter, end finish, and length selected for the assembly. :contentReference[oaicite:9]{index=9}
| Variant | Typical OD | End Finish | Pressure Range | Typical Use | Key Benefit |
|---|---|---|---|---|---|
| Transparent Tubular Gauge Glass | 1/2" OD to 1 1/2" OD | Cut / ground / fire polished | 90 to 600 psi depending on the build | Tanks, reservoirs, boilers, flowmeters | Direct liquid-level reading |
| Redline Tubular Gauge Glass | Commonly available in 5/8" and 3/4" OD forms | Fire polished in many versions | Depends on tube form and length | Low-contrast liquid-level reading | Better visibility from a distance |
| High Pressure Tubular Gauge Glass | 1/2" OD to 1 1/2" OD | Cut / ground / fire polished | Up to the upper end of the family range | More demanding level-gauge service | Stronger pressure selection |
| Heavy Wall Tubular Gauge Glass | 5/8" OD to 3/4" OD | Ground ends | 90 to 600 psi depending on end finish, diameter, and length | Higher-pressure level gauge assemblies | Highest pressure rating in the family |
| Heavy Wall Red Line Tubular Gauge Glass | Heavy-wall size range | Ground ends / application dependent | Heavy-wall service range | Demanding service with visibility needs | Combines readability and strength |
Selection Guide
How to Choose the Right Tubular Sight Glass
The correct choice depends on the fluid, visibility requirement, pressure, and the gauge body dimensions. Heavy wall glass is the strongest tubular option, red line glass improves visibility, and standard transparent tubes are the common general-purpose choice. :contentReference[oaicite:10]{index=10}
1
Confirm the service condition
Identify whether the application is for a tank, reservoir, boiler, or flowmeter. The service condition decides whether you need a standard clear tube, a red line tube, or a heavier wall construction.
2
Choose the visibility style
Use transparent tubular gauge glass for direct reading, and redline tubular gauge glass when the liquid is clear or difficult to read. If strength matters more, move to heavy wall construction.
3
Check the dimensions
Confirm the outside diameter, wall thickness, and length. Standard tubular gauge glass is commonly offered from 1/2" OD to 1 1/2" OD, and heavy wall forms are often 5/8" or 3/4" OD. :contentReference[oaicite:11]{index=11}
4
Match the end finish
End finish affects fit and pressure capability. Common options are cut, ground, and fire polished, and the final choice depends on the gauge design and the operating condition. :contentReference[oaicite:12]{index=12}
5
Request a drawing-based quote
For custom or replacement work, send a drawing or sample together with the working pressure, fluid, and length. This is the fastest way to match the correct tubular sight glass type.
Need help choosing between redline tubular gauge glass and heavy wall tubular gauge glass?
Redline improves visibility. Heavy wall improves pressure margin and heat-shock resistance. If both are needed, use the heavy wall red line version.
Contact Technical Team
Standards, Certification, and HS Code
Industry Standards and Common HS Code
Buyers often ask about standard references, inspection documents, and tariff classification before placing an order. This section gives a practical procurement summary for tubular sight glass. :contentReference[oaicite:13]{index=13}
Standard Product Family
The tubular gauge glass family is commonly offered as Standard, Red Line, High Pressure, Heavy Wall, and Heavy Wall Red Line. These product forms cover a wide range of industrial and commercial service conditions. :contentReference[oaicite:14]{index=14}
Typical Documentation
Typical buyer-requested documents include inspection reports, dimensional reports, material certificates, and certificate of conformity. These documents help confirm that the tube matches the drawing and service condition.
Heavy Wall Note
Heavy wall glass is described as the highest pressure-rated tubular glass and is extra resistant to heat shock. It is often selected when the application requires added mechanical margin. :contentReference[oaicite:15]{index=15}
Red Line Note
Red line tubular gauge glass is commonly used in tanks, reservoirs, and low-pressure boiler applications because the red stripe makes liquid level easier to read from a distance. :contentReference[oaicite:16]{index=16}
Common HS Code
A common classification reference for tubular sight glass parts is HS 7020, “Other articles of glass.” Final tariff classification may vary by country and by the exact construction of the item, so confirm with your customs broker or local import authority before shipment. :contentReference[oaicite:17]{index=17}
FAQ
Frequently Asked Questions About Tubular Sight Glass
What is tubular sight glass used for?
Tubular sight glass is used for direct liquid-level indication in tanks, reservoirs, boilers, flowmeters, and other level gauge assemblies. :contentReference[oaicite:18]{index=18}
What is the difference between transparent and redline tubular gauge glass?
Transparent tubular gauge glass is used for direct reading, while redline tubular gauge glass adds a red stripe that makes the liquid level easier to read from a distance. :contentReference[oaicite:19]{index=19}
What is the strongest tubular sight glass type?
Heavy wall glass is described as the highest pressure-rated tubular glass and is extra resistant to heat shock. :contentReference[oaicite:20]{index=20}
What sizes are available?
Common published tubular gauge glass sizes run from 1/2" OD to 1 1/2" OD, while heavy wall forms are commonly 5/8" and 3/4" OD. :contentReference[oaicite:21]{index=21}
What pressure range is available?
Published tubular gauge glass data shows pressure ratings from 90 to 600 psi depending on the product form, end finish, diameter, and length required. :contentReference[oaicite:22]{index=22}
What end finishes are available?
Common end finishes include cut, ground, and fire polished, depending on the application and the gauge design. :contentReference[oaicite:23]{index=23}
What information do you need for a quote?
Please send the product type, outside diameter, length, end finish, working pressure, working temperature, medium, quantity, and a drawing or sample if available.
What is the HS code for tubular sight glass?
A common classification reference is HS 7020, but the final code depends on the exact product structure and your destination country. :contentReference[oaicite:24]{index=24}
Download Full Tubular Sight Glass Catalogue
Get the complete product overview, size reference, material options, and application guidance in one file.
Request a Quote
Send your drawing, size, end finish, pressure, temperature, and quantity. We will review the requirement and reply with a technical quotation.
- Transparent tubular gauge glass
- Redline tubular gauge glass
- High pressure tubular gauge glass
- Heavy wall tubular gauge glass
- Custom cut length tubular sight glass
Contact Technical Team
Need help matching the correct tubular sight glass for a tank, reservoir, boiler, flowmeter, or replacement project? Contact the technical team for fast product matching.
Contact Technical Team