ASME B16.48 Spectacle Blind Flange Manufacturer

Shribhairav Forge is a leading ASME B16.48 Spectacle Blind Flange manufacturer, supplier, and exporter offering premium-quality products for industrial piping systems. Our spectacle blinds are precisely engineered to provide a safe and reliable method for isolating sections of pipelines during maintenance, inspection, or repair.

We manufacture Spectacle Blind Flanges (Figure-8 Blinds) in various materials, sizes, and pressure ratings that comply with international standards such as ASME B16.48, ANSI, DIN, ASTM, and API.

What are Spectacle Blind Flange?

A spectacle blind flange is a safety device used in piping systems to either isolate a section of the pipeline or allow flow through it. It consists of two metal discs attached side by side — one solid (the “blind”) and one with a hole (the “spacer”) — resembling a pair of eyeglasses, hence the name “spectacle.” This design allows operators to easily switch between open and closed positions by simply rotating the spectacle blind, providing a visual and physical indication of whether the line is open or blocked.

Spectacle blinds are typically installed between two pipe flanges in systems where frequent maintenance or inspection is required. During normal operation, the open end of the spectacle blind (the ring) allows flow through the pipe. When it becomes necessary to isolate a section for maintenance, the blind end is rotated into position to block the flow completely. This simple yet effective mechanism ensures safety during repairs or shutdowns by preventing accidental flow of fluids or gases.

Manufactured from materials such as stainless steel, carbon steel, or alloy steel, spectacle blind flanges are designed to withstand high pressure and temperature conditions. They are commonly used in oil and gas, chemical processing, power plants, and refinery industries, where safety and reliability are critical. The use of spectacle blinds also helps operators comply with safety standards, as their visible position makes it easy to confirm whether a line is open or closed at a glance.

Standard Specification For Spectacle Blind Flanges

Key Dimensional and Pressure Specifications

Dimensions: ANSI B16.5, ANSI B16.47 Series A & B, MSS SP44, ASA, API-605, AWWA, Custom Drawings

Size Range: 1/2" (15 NB) to 48" (1200NB)

Pressure Classes: 150 LBS, 300 LBS, 600 LBS, 900 LBS, 1500 LBS, 2500 LBS, DIN Standard ND-6,10, 16, 25, 40 Etc.

DIN Standards: DIN2527, DIN2566, DIN2573, DIN2576, DIN2641, DIN2642, DIN2655, DIN2656, DIN2627, DIN2628, DIN2629, DIN 2631, DIN2632, DIN2633, DIN2634, DIN2635, DIN2636,DIN2637, DIN2638, DIN2673

BS Standards: BS4504 , BS4504, BS1560, BS10

Flange Face Types: Flat Face (FF), Raised Face (RF), Ring Type Joint (RTJ)

These specs are validated through our in-house hydrostatic testing (up to 1.5x rated pressure) and dimensional verification using CMM (Coordinate Measuring Machines). For 2025 updates, we've incorporated ASME's revised tolerances for high-temperature deviations, ensuring slip on flanges perform flawlessly in fluctuating environments.

Specification	Class 150	Class 300	Class 600	Notes
Max Pressure (bar)	19.6	51.7	103.4	At 38°C ambient
Min Thickness (mm, 6″ size)	9.5	14.3	22.2	Per B16.5
Bolt Circle Dia. (mm, 4″)	114.3	152.4	190.5	8 holes standard
Weight (kg, 4″ CS)	1.6	2.3	4.1	Varies by material

Material & Grades of Spectacle Blind Flanges

Material selection is the heart of any spectacle blind flange's performance, and at Shribhairav Forge, we source only prime materials from LME-registered suppliers. Our portfolio spans ferrous and non-ferrous alloys, optimized for corrosion resistance (PREN values up to 40+), weldability, and environmental resilience.

Stainless Steel Spectacle Blind Flanges :

ASTM A 182, A 240 F 304, 304L, 304H, 316, 316L, 316Ti, 310, 310S, 321, 321H, 317, 347, 347H, 904L

Duplex & Super Duplex Steel Spectacle Blind Flanges :

ASTM / ASME A/SA 182 F 44, F 45, F51, F 53, F 55, F 60, F 61

Carbon Steel Spectacle Blind Flanges :

ASTM / ASME A/SA 105 ASTM / ASME A 350 , ASTM A 181 LF 2 / A516 Gr.70 A36, A694 F42, F46, F52, F60, F65, F706

Low Temperature Carbon Steel Spectacle Blind Flanges :

ASTM A350, LF2, LF3

Alloy Steel Spectacle Blind Flanges :

ASTM / ASME A/SA 182 & A 387 F1, F5, F9, F11, F12, F22, F91

ANSI B16.48 Spectacle Blind Flanges Application

ASME B16.48 Spectacle Blind Flanges are known to deliver exceptional performance and are generally developed for meeting the demands. We offer a broad range of Spectacle Blind Flanges through a worldwide network of stock-keeping branches. These Spectacle Blind Flange is use in various industries like :

Stainless Steel Spectacle Blind Flanges uses in Oil and Gas Pipeline
Spectacle Blind Flanges uses in Chemical Industry
Alloy Steel Spectacle Blind Flanges uses in Plumbing
Flat Faced Spectacle Blind Flanges uses in Heating
Spectacle Blind Pipe Flanges uses in Water Supply Systems
ANSI B16.48 Spectacle Blind Forged Flanges uses in Power Plant
Spectacle Blind Plate Flanges uses in Paper & Pulp Industry
Spectacle Blind Flange uses in General Purpose Applications

FAQs

How do you ensure consistent service quality?

We maintain consistent service quality by implementing rigorous training programs, regularly updating our processes, and gathering feedback from customers. This allows us to continuously improve and adapt to their needs, ensuring high standards are met at every touchpoint.

What key factors create memorable customer experiences?

Memorable customer experiences are created by understanding customer needs, providing personalized interactions, ensuring prompt responses, and maintaining a positive, friendly attitude. Consistency in service quality and exceeding expectations are also essential for lasting impressions.

How do you handle customer issues efficiently?

We handle customer issues efficiently by actively listening, identifying the root cause, and offering timely solutions. Clear communication and regular updates keep customers informed, while swift action and follow-up ensure a positive resolution.

What sets your service apart from competitors?

Our service stands out through personalized attention, quick response times, and a commitment to continuous improvement. We prioritize customer satisfaction, consistently adapting to feedback and industry trends to deliver exceptional, tailored experiences.