250°C High Temp Tank Level Sight Glass – 316L Stainless Steel, Flanged End, 1.6MPa Pressure Rating for Boilers & Storage Tanks

  • 250°C High Temp Rating:Engineered for extreme thermal cycling in boiler steam drums, superheaters, and high-temperature storage vessels where standard glass fails.

  • 316L Stainless Steel & Borosilicate Glass:All wetted parts constructed from high-grade 316L stainless steel with a high-transparency borosilicate glass viewing window – ensuring exceptional corrosion resistance, thermal shock tolerance, and long service life in aggressive process environments.

  • Flanged End Connection:Direct bolt-on replacement for existing tank nozzles with zero welding required, minimizing installation downtime and labor cost.

  • 1.6MPa Pressure Rating (232 PSI):Certified for pressurized tanks and vessels, delivering safe, leak-free visual level indication under demanding process conditions.

  • Instant Visual Indication:Provides clear, real-time liquid level sight glass for tanks reading with no electronics, no calibration, no power needed – just reliable visual monitoring at a glance.

  • Versatile Tank Compatibility:Works as a tank level sight glass for water tanks, chemical storage, hydraulic reservoirs, fuel tanks, and industrial pressure vessels.

  • Customizable Options Available:Available in custom flange sizes, pressure ratings, center-to-center distances, and visual indicator scales to match your specific tank sight glass level indicators and installation requirements.

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What Is This Tank Level Sight Glass?

This 250°C high temp tank level sight glass is a visual liquid level indicator designed for direct mounting on boilers, storage tanks, and pressure vessels. Constructed from 316L stainless steel with a borosilicate glass viewing window and flanged end connections, it provides instant, accurate level readings in high-temperature, high-pressure process environments.

Unlike electronic level sensors, this sight glass requires no power, no calibration, and no maintenance – delivering reliable visual indication 24/7, even in extreme conditions.

Anatomy of the Tank Level Sight Glass
Understanding what’s inside helps you trust what’s outside. Here’s how each component contributes to reliable performance:

ComponentMaterial / SpecificationDescription
Flange ConnectionANSI / DIN / JIS availableFactory-standard flanged ends on this tank level sight glass enable direct bolt-on mounting to your existing tank nozzles. No welding, no modifications – just bolt, seal, and read.
Borosilicate Glass WindowHigh-temp glass rated to 250°CHigh-transparency, thermal-shock-resistant glass provides crystal-clear visual indication of liquid level – making it an ideal sight glass for tanks operating at continuous 250°C.
PTFE / Graphite Gasket Seal
PTFE or Graphite optionalZero-leakage sealing system ensures process integrity under 1.6MPa pressure. As a trusted tank sight glass level indicator, gasket materials are selectable for your specific media compatibility.
316L Stainless Steel Body316L Stainless SteelAll wetted surfaces are 316L SS – maximum resistance to corrosion, pitting, and chemical attack. This sight glass for fuel tank applications also performs well in seawater, acids, and hydrocarbons.
Lower Flange ConnectionANSI / DIN / JIS availableSymmetrical design allows for bi-directional installation, accommodating both top-mount and side-mount configurations for versatile tank level gauge sight glass setups.

This tank level sight glass is commonly installed on:

  • Boiler steam drums and water columns – Withstands 250°C continuous operation, making it a dependable sight glass for tanks in power generation and industrial heating systems where high-temperature visibility is critical.

  • Chemical storage tanks – 316L stainless steel construction resists corrosion from aggressive media, ensuring long-term performance as a tank sight glass level indicator for chemical processing facilities.

  • Hydraulic fluid reservoirs – Provides instant visual verification of fluid levels, serving as a robust hydraulic tank level sight glass in heavy machinery and mobile equipment.

  • Fuel oil storage tanks – Delivers safe, leak-free visual monitoring for fuel inventories, widely used as a sight glass for fuel tank in power plants and marine vessels.

  • Pharmaceutical mixing vessels – Clean, corrosion-resistant design meets sanitary requirements, functioning as a reliable liquid level sight glass for tanks in pharmaceutical production.

  • Food processing tanks – Non-reactive 316L stainless steel and sealed construction make it a hygienic sight glass for tanks suitable for food and beverage manufacturing.

  • Water treatment tanks – Delivers accurate visual level monitoring as a water tank level sight glass in municipal and industrial water treatment facilities.

  • Pressure vessels and storage tanks – Serves as a precision tank level gauge sight glass for continuous level monitoring in stationary and mobile storage applications.

ParameterSpecificationNotes
Product NameHigh Temperature Tank Level Sight GlassTank level sight glass series
ModelTSLG SeriesCustom models available
Material – Body316L Stainless Steel / Carbon Steel / SS304316L recommended for corrosive media 
Material – GlassBorosilicate Glass 3.3High-transparency, thermal-shock-resistant 
Glass TypeTransparent / Reflex type availableReflex for dark/light level differentiation 
Working Temperature0°C – 250°C (Standard); Up to 450°C (Optional)For high-temp boiler applications 
Working Pressure1.6MPa (232 PSI) Standard; Up to 16MPa CustomizableCertified for pressurized tanks 
Connection TypeFlanged End (ANSI / DIN / JIS)DN15, DN20, DN25, DN40, DN50; 3/4″, 1″, 1-1/4″, 1.5″, 2″ 
Center-to-Center Distance300mm – 2000mm StandardCustom lengths available 
Visible Length95mm – 3360mmVaries by model 
Gasket MaterialPTFE / Graphite / Non-AsbestosSelectable based on media compatibility 
Sealing SystemZero-leakage with safety steel ballAuto-shutoff on glass damage 
Warranty18 MonthsStandard coverage
CertificationsISO9001:2000, CEQuality assured 
PackagingWooden Box or as requestedFor export shipping

Technical Description

The tank level sight glass operates on the communicating vessel principle – the liquid chamber within the gauge body connects to the tank through upper and lower flanges, allowing the liquid level inside the sight glass to rise and fall identically to the level inside the tank .

The borosilicate glass viewing window provides crystal-clear visual indication of the liquid level, with the transparency allowing operators to see not just the level but also the clarity, color, and condition of the process fluid .

Safety features include a spring-loaded steel ball mechanism in both upper and lower valves. In the event of glass breakage, the steel ball automatically seals the flow path, preventing hazardous leakage and protecting personnel .

Ianstalltion flexibility is ensured through bi-directional flanged connections that accommodate both top-mount and side-mount configurations, making this sight glass level indicator for tanks suitable for a wide range of industrial setups 、

Complies with Lead Free Plumbing Laws, NSF/ ANSI 61, UPC/ CE, ISO 9001

For approval information, please refer to the products specification sheet. For any other information on product certification and documentation information, please contact Fanovo.

FANOVO STATEMENT OF WARRANTY & LIMITATION OF WARRANTY
Fanovo warrants, to our all purchasers, that its products which are delivered to its purchasers will be the kind described in the order or price list and will be free of defects in workmanship or material for a period of two year from the date of shipping to you, our purchaser.
Should any failure to conform to this warranty appear within two year after the date of the initial delivery to our purchaser, Fanovo will, upon written notification thereof and substantiation that the goods have been stored, installed, maintained and operated in accordance with Fanovo’s recommendation and standard industry practice, correct such defects by suitable repair or replacement at Fanovo’s own expense. If any valve alleged to be defective, is reported to Fanovo headquarter in China, it will be examined and, if found to be defective under the warranty, it will be replaced at no charge in future order.
THIS WARRANTY IS EXCLUSIVE AND IS IN LIEU OF ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR OTHER WARRANTY OF QUALITY, WHETHER EXPRESS OR IMPLIED, EXCEPT THE WARRANTY OF TITLE AND AGAINST PATENT INFRINGEMENT Correction of non-conformities, in the manner and for the period of time provided above, shall constitute fulfillment of all liabilities of Fanovo to our purchaser, with respect to the goods, whether based on contract, negligence, strict tort or otherwise, it is the intention of Fanovo that no warranty of any kind, whether express or implied, shall pass through our purchaser to any other person or corporation.
LIMITATION OF LIABILITY: FANOVO SHALL NOT UNDER ANY CIRCUMSTANCES BE LIABLE FOR SPECIAL OR CONSEQUENTIAL DAMAGES SUCH AS, BUT NOT LIMITED TO, DAMAGES OR LOSS OF OTHER PROPERTY OR EQUIPMENT, LOSS OF PROFITS, OR REVENUE, COST OF CAPITAL, COST OF PURCHASED OR REPLACEMENT GOODS, OR CLAIMS OF CUSTOMERS OF OUR INITIAL PURCHASER. THE REMEDIES OF OUR INITIAL PURCHASER, AND ALL OTHERS, SET FORTH HEREIN ARE EXCLUSIVE, AND THE LIABILITY OF FANOVO WITH RESPECT TO SAME SHALL NOT, EXCEPT AS EXPRESSLY PROVIDED HEREIN, EXCEED THE PRICE OF GOODS UPON WHICH SUCH LIABILITY IS BASED.

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