Spectacle Flanges - Pumps, Valves, Piping and Fittings
Spectacle flanges, also called figure-eight blinds, are piping isolation devices with one solid blind and one open ring joined by a web. They are used on marine pump, valve, piping and fitting systems to provide visible, positive line isolation during operation or maintenance.
ProShipWorks provides end-to-end support to source and supply Spectacle Flanges for marine vessels, ship operators, industrial facilities, maintenance teams and procurement departments.
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Product Information
| Product Name | Spectacle Flanges |
|---|---|
| Product Category | Pumps, Valves, Piping and Fittings |
| Product Reference | 636 |
| Unit of Measure | Piece |
Key Features
| Key Feature |
|---|
| 1. Combines a blind plate and spacer ring in one assembly |
| 2. Provides visible and positive mechanical isolation |
| 3. Available in carbon steel, stainless steel and alloy materials |
| 4. Manufactured for raised-face, flat-face or ring-type joint connections |
| 5. Suitable for seawater, ballast, fuel, cargo, steam and utility piping |
Applications of Spectacle Flanges
| Application |
|---|
| 1. Pump suction and discharge piping isolation |
| 2. Valve, manifold and marine piping maintenance |
| 3. Ballast, bilge, fuel, cargo, fire main and seawater systems |
Models & Manufacturers
| Model | Manufacturer |
|---|---|
| ASME B16.48 Spectacle Blind | Various qualified flange manufacturers |
| EN 1092-1 Figure-8 Blind | Various qualified flange manufacturers |
Technical Specifications
| Model | Specification | Value | Unit |
|---|---|---|---|
| ASME B16.48 Spectacle Blind | Nominal size | NPS 1/2 to NPS 24 commonly; larger sizes available by agreement | NPS |
| ASME B16.48 Spectacle Blind | Pressure class | Class 150, 300, 600, 900, 1500 and 2500 | Class |
| EN 1092-1 Figure-8 Blind | Nominal pressure | PN 6, PN 10, PN 16, PN 25, PN 40, PN 63, PN 100 and higher by design | bar |
| General marine supply | Common materials | Carbon steel, stainless steel, duplex stainless steel and nickel alloys | — |
| General marine supply | Face types | Raised face, flat face and ring-type joint | — |
Standards, Certifications & Class Approval
Review the available standards and approval information relevant to the product. Actual certification, material traceability, inspection and classification requirements depend on the product type, intended application and purchasing specification.
| Applicable Standards & Certification | Common dimensional standards include ASME B16.48 for line blanks, ASME B16.5 for smaller flanges, ASME B16.47 for large-diameter flanges, and EN 1092-1. Material certification may be supplied to EN 10204 3.1 or project requirements. |
|---|---|
| Class Approval | May be accepted for shipboard piping subject to the applicable piping design, material certification and class requirements. DNV, ABS, Lloyd's Register, Bureau Veritas and ClassNK requirements may apply; product approval is not automatic and must be confirmed for the vessel project. |
Installation, Maintenance & Safety Information
| Installation Notes | Confirm pipe size, flange standard, pressure class, face type, material and gasket compatibility. Depressurize, drain and gas-free the line before loosening bolts. Install the correct face toward the gasket, align bolt holes, and tighten bolts using the specified cross-pattern torque. |
|---|---|
| Maintenance Tips | Inspect periodically for corrosion, deformation, leakage and damaged bolt holes. Verify the operating position of the blind or open ring after maintenance. Replace damaged gaskets and renew or repair corroded units according to the approved piping procedure. |
| Safety Notes | Treat the line as pressurized until positively isolated, drained and verified gas-free. Use lockout/tagout and permit-to-work procedures. Confirm that the spectacle blind rating exceeds system pressure and temperature, and use suitable lifting equipment for large or heavy assemblies. |
Request a Quote for Spectacle Flanges
Contact ProShipWorks for marine or industrial product sourcing, quotations and delivery.
- Vessel name and IMO number
- ETA / vessel schedule
- Berth or vessel location
- Required quantity
- Preferred delivery window
- Shipping agent contact details
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