Figure 8 Blank Throttle Plate Double Sided Marine ASME B16.48 Spectacle Blind

Figure 8 Blank Throttle Plate Marine Spectacle Blind Nickel Alloy Flange 

A Figure 8 blank, commonly known as a Spectacle Blind, is a safety device used in pipelines and other pressurized flows, deployed to isolate sections of a line. It is called "Figure 8" due to its shape, which resembles the number 8, with one side being a solid disk (blind) and the other a ring (spacer).

Design and Structure:

1. Double-Sided Design:

Blind End: One section is a solid disk used to stop flow and completely shut off the pipeline.

Spacer End: The other section is an open ring allowing the normal flow when the line does not need to be isolated.

2. Connecting Web: The two parts are connected by a handle, making it easy to switch between the blind and open positions.

Materials:

Nickel Alloys: Known for their excellent resistance to corrosion and high-temperature strength, typical nickel alloys used include:

• Inconel (Alloy 600, Alloy 625): Exceptional resistance to oxidation and corrosion.
• Monel (Alloy 400): Resistant to seawater and steam at high temperatures as well as salt and caustic solutions.
• Hastelloy (C-276, C-22): Outstanding resistance to a wide range of chemical processes.
• Nickel 200/201: Pure nickel with excellent mechanical properties and corrosion resistance.

Applications:

1. Oil and Gas Industry: Used in pipelines to isolate sections for maintenance or if there's a need to adjust flow paths.
2. Chemical Processing Plants: Essential for isolating segments of pipework carrying aggressive and corrosive chemicals.
3. Power Generation: Used in steam and gas systems to ensure safe and efficient flow isolation during operations and maintenance.
4. Marine and Aerospace: Employed in systems where high strength and corrosion resistance are critical.

Benefits:

1. Safety: Provides a reliable method of isolating pipeline sections, reducing the risk of spillage or accidents during maintenance.
2. Durability: Nickel alloys provide excellent durability and longevity in harsh environments.
3. Versatility: Can be used in a range of temperatures and pressures, making them suitable for various industrial applications.
4. Corrosion Resistance: High resistance to corrosion reduces the frequency of replacements and maintenance, thus lowering operational downtime.

Standards and Specifications:

1. ASME B16.48: Covers the dimensions and materials for line blanks, including Spectacle Blinds, for use in piping systems.
2. ISO 9001: Ensures that the manufacturing of these components meets international quality management standards.

Customization Options:

1. Size and Thickness: Can be tailor-made to fit specific pipeline dimensions and pressure requirements.
2. Surface Treatment: Can be coated or treated for enhanced resistance to certain environments.
3. Documentation: Material test reports, pressure test reports, and certificates of conformance can be provided as required.

This comprehensive overview should provide a clear understanding of the details concerning Nickel Alloy Figure 8 blanks (Spectacle Blinds) and their applications in various industries.