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What is a Spectacles Blind Flange?
A Spectacles Blind Flange, also known as a figure-8 flange or spectacle blind, is a safety device used in piping systems to isolate sections of a pipeline or facilitate maintenance. It consists of two metal discs – one solid (the blind) and one with a hole (the spacer) – connected by a small piece of metal resembling a pair of spectacles. By rotating the assembly, the blind can block the flow entirely or allow it to pass through the spacer.
This flange is commonly used in oil and gas, petrochemical, power generation, and refinery industries where safety and control over flow are critical.
Why Choose a Spectacle Blind Flange?
When it comes to controlling flow and ensuring operational safety, a Spectacles Blind Flange offers several unique advantages:
✅ Positive shut-off: Guarantees zero flow when the blind end is in use.
✅ Simple operation: Easy to rotate between open and closed positions.
✅ Visual confirmation: The position of the flange clearly shows whether the line is open or shut.
✅ Durable construction: Manufactured from carbon steel, stainless steel, alloy steel, or custom materials to match your needs.
✅ Pressure ratings: Available in ANSI/ASME classes 150, 300, 600, 900, 1500, and 2500.
Common Applications
Spectacle blind flanges are ideal for:
Maintenance and inspection: Easily isolate parts of the pipeline.
Safety shut-offs: Ensure zero-leak isolation during emergency or planned shutdowns.
Temporary or permanent blockage of pipeline segments without removing the flange.
Systems operating in harsh environments require regular servicing or inspection.
Types of Spectacle Blinds
There are variations of the spectacle blind flange based on design requirements:
Paddle Blind (Spade): A solid disc is used when frequent disassembly is unnecessary.
Paddle Spacer (Ring Spacer): A ring-shaped disc allowing flow, used with paddle blinds.
Spectacle Blind: A combination of the above two is used where switching between open and closed flow is needed without removing the flange.
Manufacturing Standards and Specifications
Our Spectacles Blind Flanges are manufactured in compliance with global standards:
ASME B16.48
ANSI B16.5
API, DIN, EN, JIS (available upon request)
Available in sizes from 1/2″ to 48″
Custom thickness and dimensions for high-pressure or special applications
Materials and Surface Treatment
To meet diverse industrial needs, we provide spectacle blind flanges in materials such as:
Carbon Steel (A105, A516 Gr.70, etc.)
Stainless Steel (304, 316, 321, 347, etc.)
Duplex & Super Duplex Steel
Alloy Steel (F11, F22, F91, etc.)
Surface treatments include black paint, anti-rust oil, galvanizing, or custom coatings based on your project requirements.
Why Choose Us for Spectacles Blind Flange Supply?
🌐 Global Export Experience: Trusted by clients in over 50 countries
🏭 Factory Direct: Competitive prices and strict quality control
📦 Careful Packaging: Each flange is packed for safety and durability
🕒 Timely Deliveries: On-time shipment through major ports like Tianjin, Shanghai, and Ningbo
🔍 Customized Service: Drawings and technical consultation available for non-standard requirements
Order Now – Reliable Flow Control Starts Here
Whether you’re working on a new pipeline project or upgrading an existing system, our spectacle blind flanges are the perfect solution to ensure safety, reliability, and ease of maintenance.
Contact us today for a free quote or technical consultation. Let us support your next project with flanges that are built to perform.