Types, applications and standards of spectacle blind flanges
What is a Spectacle Blind Flange?
A spectacle blind flange is a piping component used to isolate sections of a pipeline or to temporarily shut off the flow for maintenance and safety purposes. It consists of two metal discs connected by a small bridge—one disc is solid (blind), blocking flow, while the other has an open bore, allowing flow to pass. By rotating the spectacle blind, operators can easily switch between an open and closed position without removing the flange from the system.
These flanges are commonly used in applications where frequent flow isolation is required, ensuring a reliable and efficient solution for pipeline maintenance and operational safety.
spectacle blind flanges
Main Applications of Spectacle Blind Flanges
Spectacle blind flanges are widely used in industries where safe and efficient pipeline operation is critical. Some of the key applications include:
Oil & Gas Pipelines – Used in refineries and offshore platforms for flow isolation and maintenance.
Chemical Processing Plants – Essential for controlling the flow of hazardous chemicals.
Marine & Offshore Engineering – Protects pipelines and ensures safety in marine environments.
Liquefied Natural Gas (LNG) Facilities – Maintains flow control in extremely low-temperature applications.
Power Plants – Ensures safety in high-pressure steam and water pipelines.
Stainless steel SS316 spectacle blind flange
Standards and Specifications for Spectacle Blind Flanges
To ensure reliability and compatibility, spectacle blinds must meet international industry standards. The most recognized standards include:
ASME B16.48 – The primary standard for spectacle blinds, spades, and spacers, specifying dimensions and materials.
ASME B16.5 – Defines the flange types and dimensions, ensuring proper fit with spectacle blinds.
ASTM A240 – Governs the material specifications for stainless steel and duplex steel spectacle blinds.
EN 10204-3.1 Certification – Provides material traceability and quality assurance with a certified test report.
Haihao Group ensures that all spectacle blind flanges comply with these strict standards, guaranteeing high-quality, durable products for critical applications.
Haihao Group’s Expertise in Spectacle Blind Flange Manufacturing
As a leading manufacturer of pipeline components, Haihao Group produces all kinds of high-quality Spectacle Blind including stainless steel ASTM A240 316/316L and duplex steel S31803 spectacle blind flanges. Our manufacturing process includes:
Precision Machining – Using advanced CNC machines to meet exact specifications.
Material Selection – Sourcing high-grade stainless steel and duplex steel for corrosion resistance and strength.
Stringent Quality Control – Conducting dimensional checks, material analysis, and pressure testing.
Certification Compliance – Providing EN 10204-3.1 certificates to guarantee product traceability and quality.
With decades of experience in pipeline isolation solutions, Haihao Group delivers reliable, high-performance spectacle blind flanges that meet global industry demands.
Spectacle blind flanges are an essential component in many industries, offering a simple yet effective method for pipeline isolation and maintenance. By adhering to ASME B16.48, ASME B16.5, and ASTM A240 standards, Haihao Group ensures the highest quality products for our customers. Whether for oil & gas, LNG, or chemical processing, our spectacle blind flanges provide superior performance, durability, and compliance with international regulations.
For more information or to place an order, contact Haihao Group today! Email:sales@haihaogroup.com