Sight Flow Indicators (SFI)
Precision level gauges for critical visibility in boilers, pressure vessels, and industrial processes
About Sight Flow Indicators (SFI)
Sight Flow Indicators, also known as sight glasses or level gauges, are essential visual measurement devices that allow operators to observe the liquid level inside tanks, boilers, pressure vessels, and reactors. These precision instruments provide real-time visibility into critical process levels, ensuring safe and efficient operation of industrial equipment. Our sight flow indicators are engineered for reliability, safety, and clarity in demanding industrial environments ranging from power plants to pharmaceutical facilities.
We offer multiple gauge types to suit various applications: Reflex Gauges for superior liquid/gas distinction with minimal obstruction, Bi-Colour Gauges for enhanced visibility in caustic or high-pressure environments, Magnetic Indicators for safety-critical applications where glass contact with hazardous media must be avoided, and Tubular Gauges for simple, cost-effective level observation. Each gauge type features robust metal construction with protective shrouding, safety ball valves, and mechanically prestressed glass designed to withstand pressures up to 400 bar and temperatures exceeding 300°C.
Manufactured to international standards including ASME Boiler & Pressure Vessel Code, ISO 1803, and DIN 3353, our sight flow indicators feature materials in stainless steel, carbon steel, duplex, and specialty alloys. Every gauge is precisely engineered with safety as paramount—automatic ball valves limit media release during glass failure, and patterned backplates enhance readability under varying conditions. Whether for steam boilers, chemical reactors, oil processing, food production, or pharmaceutical manufacturing, our sight flow indicators deliver the precision and durability your critical processes demand.
Available Models
Choose from our comprehensive range of sight flow indicator gauge types and configurations
Specifications & Details
Comprehensive information about our sight flow indicator systems
1Gauge Types Available
- ▪Reflex Gauges - Clear liquid/gas distinction with silvery white appearance for liquid
- ▪Bi-Colour Gauges - Red for gas, green for liquid for enhanced visibility
- ▪Magnetic Indicators - No glass contact, safe for high pressure/temperature
- ▪Tubular Gauges - Simple transparent tube design for basic applications
2Technical Specifications
- ▪Pressure Rating: Up to 400 Bar (depending on gauge type)
- ▪Temperature Range: -20°C to +300°C for standard designs
- ▪Glass Material: Soda-lime or Borosilicate for superior corrosion resistance
- ▪Connection Standards: ANSI, DIN, ISO, and BS 10 flanged connections
3Construction Features
- ▪Metal shroud protection against impact and scratching
- ▪Patterned backplate for improved readability
- ▪Safety ball valves to limit media release in case of glass failure
- ▪Mechanically prestressed glass for enhanced durability
- ▪Bolted or fused metal-to-glass assembly
4Applications
- ▪Steam Boilers & Pressure Vessels
- ▪Chemical Plants & Reactors
- ▪Oil & Gas Processing
- ▪Food & Beverage Production
- ▪Pharmaceutical Manufacturing
- ▪Bio-Gas Plants & Digesters
5Body Materials
- ▪Stainless Steel (304/316) - Standard choice
- ▪Carbon Steel with protective coating
- ▪Duplex/Super Duplex for highly corrosive environments
- ▪Aluminum alloy options for lightweight applications
6Safety & Compliance
- ▪ASME Boiler & Pressure Vessel Code compliant
- ▪National Board of Boiler & Pressure Vessel Inspectors approved
- ▪ISO 1803 & DIN 3353 standards
- ▪Regular inspection and testing procedures per ANSI standards
- ▪Emergency shut-off valves for operator safety
7Maintenance & Service
- ▪Easy glass tube replacement in the field
- ▪Regular flushing recommended to prevent scale buildup
- ▪Daily testing procedures per ANSI/National Board recommendations
- ▪Pre-cut spare tubes and seals kits available
- ▪Professional installation and calibration services
Why Choose Avant Tech Sight Flow Indicators?
Industry-leading expertise and exceptional service quality
State-of-the-Art Facility with In-House Pressure Drop Testing
At Avant Tech we partner with Flometriq Filtration, which operates from a 45,000 sq.ft. world-class combined manufacturing and testing facility equipped with advanced machinery and instrumentation. Our in-house Pressure Drop Testing Lab ensures every strainer is validated for maximum efficiency and reliability under real-world conditions.
Expert Design Team with 30+ Years of Experience
At Avant Tech we partner with Flometriq Filtration, a trusted basket type strainer manufacturer, our design team brings over four decades of expertise in creating innovative and reliable filtration solutions. Whether it's a standard model or a customized design, our team ensures every solution meets the highest industry standards for quality and efficiency.
Exceptional After-Sales Support
Our commitment to customer satisfaction goes beyond delivery. With a dedicated support team, we provide guidance on installation, maintenance, and troubleshooting to ensure the long-term performance of your equipment.
Prompt Delivery
As a leading supplier, we understand the importance of timely delivery for industrial operations. With standard models in stock and an efficient supply chain, we ensure your orders are delivered on time, every time.
Manufacturing Facility Gallery
Explore our state-of-the-art manufacturing facility
Ready to Optimize Your Level Visibility?
Contact our mechanical engineering team to find the right sight flow indicator solution for your pressure vessels, boilers, and industrial processes.