Spectacle blind flanges
A figure-8 plate with one solid and one open disc, for isolating or opening a line. Also supplied as separate spacers and paddle blanks. [CONFIRM: this type is made]
3D model
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Key to the letters
This model is drawn to typical proportions. The catalogue has no dimension table for this type yet, so no figures are shown. [CONFIRM: dimension table for this type]
Specification
- Type
- Spectacle blind
- Model shown
- Illustrative model, drawn to typical proportions
- Units
- mm, inches for ASME sizes
- Sizes
- ½" to 24" NB (DN 15 to DN 600). [CONFIRM: sizes]
- Ratings
- ASME Class 150, 300, 600, 900, 1500 and 2500. PN 6 to PN 100. JIS 5K to 20K. [CONFIRM: ratings]
- Facings
- Raised face (RF), flat face (FF), ring type joint (RTJ), tongue and groove (T&G), and male and female (M&F). Standard serrated finish, 3.2 to 6.3 µm Ra (125 to 250 µin). Smooth finish on request. [CONFIRM: facings]
- Standards
- ASME B16.5 (NPS ½" to 24"), EN 1092-1 (DN 15 to DN 600), DIN, BS 4504, BS 10 (Tables D, E, F and H), JIS B2220, IS 6392. [CONFIRM: standards for spectacle blind]
- Materials
- Carbon steel A105 and A105N. Carbon steel plate E250. Low-temperature carbon steel LF2 Class 1 and LF3. Alloy steel F1, F5, F9, F11, F12, F22 and F91. [CONFIRM: grades]
- Finishes
- Rust-preventive oil and black anti-rust paint. [CONFIRM: finishes]
- Documents and inspection
- EN 10204 3.1 material test certificate. Dimensional inspection report. Third-party inspection on request, for example BV, SGS, TÜV, Lloyd’s Register, DNV.
The marking, explained
Every flange is stamped on its rim, so it can be traced to its heat and its material certificate. Choose any part of the stamp to see what it means.
150Class
Pressure class, here 150 to ASME B16.5. The pressure it can hold at a given temperature depends on the material.
This is an example stamp for a 6" Class 150 weld neck; the stamp on your flange carries its own size, class and grade. HT 24A117 is a sample heat number. The stamp follows MSS SP-25.
[CONFIRM: exact stamp format and the mark we stamp]
Dimensions
No dimension table yet
The catalogue has no dimension table for spectacle blind flanges, so no figures are shown here and the 3D model is drawn to typical proportions. [CONFIRM: dimension table for spectacle blind flanges]
Where it’s used
A figure-8 plate with one solid and one open disc, for isolating or opening a line. Also supplied as separate spacers and paddle blanks.
[CONFIRM: where spectacle blind flanges are used]
Industries: oil and gas, refining and petrochemical, power generation, water and wastewater, chemical and fertiliser, and general fabrication.
By material
- Carbon steel
- General service, from ambient to elevated temperatures
- Carbon steel plate
- Plate flanges
- Low-temperature carbon steel
- Low-temperature service. LF2 Class 1 is impact-tested at −46 °C.
- Alloy steel
- High-temperature service in power and refining
Related types
Blind
A solid flange that closes off a pipe end, valve or vessel opening, and comes off to give access for inspection.