Precision-Engineered ASME B16.48 Spectacle Blind Flange
Fortune Fittings Pvt. Ltd. is a leading manufacturer and supplier of high-quality Spectacle Blind Flanges, designed to meet the rigorous demands of various industrial applications. As per ASME B16.48 standards, our Spectacle Blind Flanges are crafted to provide reliable performance and durability.
What is a Spectacle Blind Flange?
A Spectacle Blind Flange is an essential component used to temporarily or permanently block off a section of a pipeline or vessel. It consists of two metal discs – one solid and one with a hole in the center – connected in a “Figure 8” shape. This configuration allows for easy switching between an open and closed position, providing versatility in maintenance and inspection processes.
Applications and Standards
Spectacle Blind Flanges are ideal for applications requiring frequent maintenance or inspection. They are manufactured according to ASME B16.48 standards, ensuring consistent dimensions, materials, and tolerances. These flanges are available in various sizes and pressure ratings, making them suitable for a wide range of applications in the oil and gas, petrochemical, and power generation industries.
Spectacle Blind Flanges Standard Specifications
- Standards: ANSI B16.5, ANSI B16.47, ANSI B16.36, ANSI B16.48, BS 4504, EN1092, UNI 2277/2278, DIN, JIS, SABS1123, GOST-12820
- Form: SORF, WNRF, BLRF, SWRF, LAP Joint, Threaded, Reducing, Spectacle
- Face Type: Flat Face (FF), Raised Face (RF), Ring Joint (RJT)
- Dimensions: ANSI B16.5, ANSI B16.47 Series A & B, MSS SP44, ASA, API-605, AWWA, Custom Drawings
- Size Range (inches): From ½” (15 NB) to 48″ (1200NB)
- Class: 150 LBS, 300 LBS, 600 LBS, 900 LBS, 1500 LBS, 2500 LBS, DIN Standard ND-6, 10, 16, 25, 40.
- Connection Type: RTJ, Lap-Joint Face, Raised Face, Flat Face, Large Male-Female, Small Male-Female, Large Tongue & Groove, Small Tongue & Groove
Features and Benefits
Product Range
At Fortune Fittings Pvt. Ltd., we maintain a ready inventory of Spectacle Blind Flanges in various sizes and classes, including 2 Inch Class 150, 4 Inch Class 300, 6 Inch Class 600, and 8 Inch Spectacle Blind Flange. Our products are manufactured to meet ANSI, BS, DIN, and other international standards.
Why Choose Fortune Fittings Pvt. Ltd.?
With a commitment to precision manufacturing and customer satisfaction, Fortune Fittings Pvt. Ltd. ensures that all Spectacle Blind Flanges meet or exceed industry standards. Our advanced manufacturing processes and quality control measures guarantee the durability and reliability of our products. We offer competitive pricing, excellent customer service, and quick turnaround times to meet the demands of your projects.
Conclusion
In conclusion, Fortune Fittings Pvt. Ltd. is your go-to source for high-quality Spectacle Blind Flanges, engineered to meet diverse industrial standards and specifications. Our extensive range of materials, sizes, and pressure ratings ensures that we can cater to various application needs. With our dedication to quality and customer service, we are a trusted partner for all your flange requirements.
For detailed information and to view our complete range of Spectacle Blind Flanges, visit our website or contact us directly. Trust Fortune Fittings Pvt. Ltd. for high-quality flange solutions tailored to your specific needs.
Flanges Dimensions
Dimensions Weld Neck Flanges & Stud Bolts
ASME B16.5
OTHER DIA | NPS 1/2 – O.D. 21.3 | |||||
CLass | 150 | 300 | 600 | 900 | 1500 | 2500 |
DIA A | 30 | 38 | 38 | 38 | 38 | 43 |
DIA D | 90 | 95 | 95 | 120 | 120 | 135 |
THK B | 11.2 | 14.3 | 20.7 | 28.7 | 28.7 | 36.6 |
DIA G | 35.1 | 35.1 | 35.1 | 35.1 | 35.1 | 35.1 |
DIA K | 60.3 | 66.7 | 66.7 | 82.6 | 82.6 | 88.9 |
H | 47.6 | 52.6 | 58.4 | 66.4 | 66.4 | 79.4 |
NO. L | 4 | 4 | 4 | 4 | 4 | 4 |
DIA L | 15.9 | 15.9 | 15.9 | 22.2 | 22.2 | 22.2 |
Stud Bolts Diameter x Length | ||||||
DIA (in) | 1/2 | 1/2 | 1/2 | 3/4 | 3/4 | 3/4 |
lgth (mm) | 55 | 65 | 75 | 110 | 110 | 120 |
- IMPORTANT! please read this short article
Dimensional Tolerances of Weld Neck Flanges ASME B16.5

Dimensions Slip On Flanges & Stud Bolts
ASME B16.5
OTHER DIA | NPS 1/2 ID 22.3 | |||||
CLass | 150 | 300 | 600 | 900 | 1500 | 2500 |
DIA A | 30 | 38 | 38 | 38 | 38 | … |
DIA D | 90 | 95 | 95 | 120 | 120 | … |
THK B | 11.2 | 14.3 | 20.7 | 28.7 | 28.7 | … |
DIA G | 35.1 | 35.1 | 35.1 | 35.1 | 35.1 | … |
DIA K | 60.3 | 66.7 | 66.7 | 82.6 | 82.6 | … |
H | 15.6 | 22.6 | 28.4 | 38.4 | 38.4 | … |
NO. L | 4 | 4 | 4 | 4 | 4 | … |
DIA L | 15.9 | 15.9 | 15.9 | 22.2 | 22.2 | … |
Stud Bolts Diameter x Length | ||||||
DIA (in) | 1/2 | 1/2 | 1/2 | 3/4 | 3/4 | … |
lgth (mm) | 55 | 65 | 75 | 110 | 110 | … |
- IMPORTANT! please read this short article
Dimensional Tolerances of Weld Neck Flanges ASME B16.5
Outside Diameter * Tolerances not listed in ASME B16.5 2013≤24 = 1.6 mm (0.06 in)>24 = ±3.2 mm (±0.12 in) Inside Diameter ≤ 10 = ± 0.8 mm≥ 12 = + 1.6 mm / – 0 mm Outside Diameter of Hub ≤ 12 = + 2.4 mm / – 1.6 mm≥ 14 = ± 3.2 mm Diameter of Counterbore Same as for Inside Diameter Drilling Bolt Circle = 1.6 mmBolt Hole Spacing = ± 0.8 mm Eccentricity of Bolt Circle ≤ 2.1/2 = 0.8 mm max.≥ 3 = 1.6 mm max. Thickness ≤ 18 = + 3.2 mm / – 0≥ 20 = + 4.8 mm / – 0 Length thru Hub ≤ 18 = + 3.2 mm / – 0.8 mm≥ 20 = + 4.8 mm / – 1.6 mm Diameter of Contact Face 1.6 mm Raised Face = ± 0.8 mm6.35 mm Raised FaceTongue and Groove / Male-Female± 0.4 mmDimensions Socket Weld Flanges & Stud Bolts
ASME B16.5
OTHER DIA | NPS 1/2 ID=22.3 F=9.5 | |||||
CLass | 150 | 300 | 600 | 900 | 1500 | 2500 |
DIA A | 30 | 38 | 38 | … | 38 | … |
DIA D | 90 | 95 | 95 | … | 120 | … |
THK B | 11.2 | 14.3 | 20.7 | … | 28.7 | … |
DIA G | 35.1 | 35.1 | 35.1 | … | 35.1 | … |
DIA K | 60.3 | 66.7 | 66.7 | … | 82.6 | … |
H | 15.6 | 22.6 | 28.4 | … | 38.4 | … |
NO. L | 4 | 4 | 4 | … | 4 | … |
DIA L | 15.9 | 15.9 | 15.9 | … | 22.2 | … |
Stud Bolts Diameter x Length | ||||||
DIA (in) | 1/2 | 1/2 | 1/2 | … | 3/4 | … |
lgth (mm) | 55 | 65 | 75 | … | 110 | … |
- ID 2 = Depending on the wall thickness of the pipe, must bespecified by the purchaser.
- IMPORTANT! please read this short article
Dimensional Tolerances of Socket Weld Flanges ASME B16.5
Outside Diameter * Tolerances not listed in ASME B16.5 2013≤ 24 = 1.6 mm> 24 = ± 3.2 mm Inside Diameter ≤ 10 = ± 0.8 mm≥ 12 = + 1.6 mm / – 0 mm Outside Diameter of Hub ≤ 12 = + 2.4 mm / – 1.6 mm≥ 14 = ± 3.2 mm Diameter of Counterbore Same as for Inside Diameter Drilling Bolt Circle = 1.6 mmBolt Hole Spacing = ± 0.8 mm Eccentricity of Bolt Circle ≤ 2.1/2 = 0.8 mm max.≥ 3 = 1.6 mm max. Thickness ≤ 18 = + 3.2 mm / – 0≥ 20 = + 4.8 mm / – 0 Length thru Hub ≤ 18 = + 3.2 mm / – 0.8 mm≥ 20 = + 4.8 mm / – 1.6 mm Diameter of Contact Face 1.6 mm Raised Face = ± 0.8 mm6.35 mm Raised FaceTongue and Groove / Male-Female± 0.4 mm Studs are measured parallel to the axis (L) from the first to the threadwithout the chamfers (points). S = free threads equals 1/3 time bolt dia Hex bolts are measured from under the head to the top of de boltDimensions Lap Joint Flanges & Stud Bolts
ASME B16.5
OTHER DIA | NPS 1/2 ID=22.9 r=3 | |||||
CLass | 150 | 300 | 600 | 900 | 1500 | 2500 |
DIA A | 30 | 38 | 38 | 38 | 38 | 43 |
DIA D | 90 | 95 | 95 | 120 | 120 | 135 |
THK B | 11.2 | 14.3 | 14.3 | 22.3 | 22.3 | 30.2 |
DIA K | 60.3 | 66.7 | 66.7 | 82.6 | 82.6 | 88.9 |
H | 16 | 22 | 22 | 32 | 32 | 40 |
NO. L | 4 | 4 | 4 | 4 | 4 | 4 |
DIA L | 15.9 | 15.9 | 15.9 | 22.2 | 22.2 | 22.2 |
Stud Bolts Diameter x Length | ||||||
DIA (in) | 1/2 | 1/2 | 1/2 | 3/4 | 3/4 | 3/4 |
lgth (mm) | 55 | 65 | 75 | 110 | 110 | 120 |
- IMPORTANT! please read this short article
Dimensional Tolerances of Lap Joint Flanges ASME B16.5
Outside Diameter * Tolerances not listed in ASME B16.5 2013≤ 24 = 1.6 mm> 24 = ± 3.2 mm Inside Diameter ≤ 10 = ± 0.8 mm≥ 12 = + 1.6 mm / – 0 mm Outside Diameter of Hub ≤ 12 = + 2.4 mm / – 1.6 mm≥ 14 = ± 3.2 mm Diameter of Counterbore Same as for Inside Diameter Drilling Bolt Circle = 1.6 mmBolt Hole Spacing = ± 0.8 mm Eccentricity of Bolt Circle ≤ 2.1/2 = 0.8 mm max.≥ 3 = 1.6 mm max. Thickness ≤ 18 = + 3.2 mm / – 0≥ 20 = + 4.8 mm / – 0 Length thru Hub ≤ 18 = + 3.2 mm / – 0.8 mm≥ 20 = + 4.8 mm / – 1.6 mm Diameter of Contact Face 1.6 mm Raised Face = ± 0.8 mm6.35 mm Raised FaceTongue and Groove / Male-Female± 0.4 mm Studs are measured parallel to the axis (L) from the first to the threadwithout the chamfers (points). S = free threads equals 1/3 time bolt dia Hex bolts are measured from under the head to the top of de boltDimensions Threaded Flanges & Stud Bolts
ASME B16.5
OTHER DIA | NPS 1/2 | |||||
CLass | 150 | 300 | 600 | 900 | 1500 | 2500 |
DIA A | 30 | 38 | 38 | 38 | 38 | 43 |
DIA D | 90 | 95 | 95 | 120 | 120 | 135 |
THK B | 11.2 | 14.3 | 20.7 | 28.7 | 28.7 | 36.6 |
DIA G | 35.1 | 35.1 | 35.1 | 35.1 | 35.1 | 35.1 |
DIA K | 60.3 | 66.7 | 66.7 | 82.6 | 82.6 | 88.9 |
H | 15.6 | 22.6 | 28.4 | 38.4 | 38.4 | 46.4 |
NO. L | 4 | 4 | 4 | 4 | 4 | 4 |
DIA L | 15.9 | 15.9 | 15.9 | 22.2 | 22.2 | 22.2 |
Stud Bolts Diameter x Length | ||||||
DIA (in) | 1/2 | 1/2 | 1/2 | 3/4 | 3/4 | 3/4 |
lgth (mm) | 55 | 65 | 75 | 110 | 110 | 120 |
- IMPORTANT! please read this short article
Dimensional Tolerances of Threaded Flanges ASME B16.5
Outside Diameter * Tolerances not listed in ASME B16.5 2013≤ 24 = 1.6 mm> 24 = ± 3.2 mm Inside Diameter Within Limits on Boring Gauge Drilling Bolt Circle = 1.6 mmBolt Hole Spacing = ± 0.8 mm Eccentricity of Bolt Circle ≤ 2.1/2 = 0.8 mm max.≥ 3 = 1.6 mm max. Outside Diameter of Hub ≤ 12 = + 2.4 mm / – 1.6 mm≥ 14 = ± 3.2 mm Diameter of Counterbore Same as forInside Diameter Thickness ≤ 18 = + 3.2 mm / – 0≥ 20 = + 4.8 mm / – 0 Length thru Hub ≤ 18 = + 3.2 mm / – 0.8 mm≥ 20 = + 4.8 mm / – 1.6 mm Diameter of Contact Face 1.6 mm Raised Face = ± 0.8 mm6.35 mm Raised FaceTongue and Groove / Male-Female± 0.4 mm Studs are measured parallel to the axis (L) from the first to the threadwithout the chamfers (points). S = free threads equals 1/3 time bolt dia Hex bolts are measured from under the head to the top of de boltDimensions Blind Flanges & Stud Bolts
ASME B16.5
OTHER DIA | NPS 1/2 | |||||
CLass | 150 | 300 | 600 | 900 | 1500 | 2500 |
DIA D | 90 | 95 | 95 | 120 | 120 | 135 |
B | 11.2 | 14.3 | 20.7 | 28.7 | 28.7 | 36.6 |
DIA G | 35.1 | 35.1 | 35.1 | 35.1 | 35.1 | 35.1 |
DIA K | 60.3 | 66.7 | 66.7 | 82.6 | 82.6 | 88.9 |
NO. L | 4 | 4 | 4 | 4 | 4 | 4 |
DIA L | 15.9 | 15.9 | 15.9 | 22.2 | 22.2 | 22.2 |
Stud Bolts Diameter x Length | ||||||
DIA (in) | 1/2 | 1/2 | 1/2 | 3/4 | 3/4 | 3/4 |
lgth (mm) | 55 | 65 | 75 | 110 | 110 | 120 |
- IMPORTANT! please read this short article
Dimensional Tolerances of Blind Flanges ASME B16.5
Outside Diameter * Tolerances not listed in ASME B16.5 2013≤ 24 = 1.6 mm> 24 = ± 3.2 mm Inside Diameter not applicable Outside Diameter of Hub ≤ 12 = + 2.4 mm / – 1.6 mm≥ 14 = ± 3.2 mm Outside Diameter of Hub ≤ 12 = + 2.4 mm / – 1.6 mm≥ 14 = ± 3.2 mm Drilling Bolt Circle = 1.6 mmBolt Hole Spacing = ± 0.8 mm Eccentricity of Bolt Circle ≤ 2.1/2 = 0.8 mm max.≥ 3 = 1.6 mm max. Thickness ≤ 18 = + 3.2 mm / – 0≥ 20 = + 4.8 mm / – 0 Length thru Hub ≤ 18 = + 3.2 mm / – 0.8 mm≥ 20 = + 4.8 mm / – 1.6 mm Diameter of Contact Face 1.6 mm Raised Face = ± 0.8 mm6.35 mm Raised FaceTongue and Groove / Male-Female ± 0.4 mm Studs are measured parallel to the axis (L) from the first to the threadwithout the chamfers (points). S = free threads equals 1/3 time bolt dia Hex bolts are measured from under the head to the top of de bolt