Precision-Engineered ASME B16.48 Backing Ring Flange
Fortune Fittings Pvt. Ltd. stands as a leading manufacturer and supplier of Backing Ring Flanges, offering premium-grade solutions tailored to meet diverse industrial requirements. Our Backing Ring Flanges, compliant with ANSI B16.5 standards, provide robust support and reinforcement for Stub Ends in piping systems.
Understanding Backing Ring Flanges
Backing Ring Flanges serve as essential components in piping systems, offering support and reinforcement for Stub Ends. Crafted from high-quality Ductile Iron, these flanges are designed to fit over the outside diameter of Stub Ends, providing structural integrity and stability to the pipeline.
Features and Benefits
Our Backing Ring Flanges boast dimensions similar to standard flanges, with evenly spaced bolt holes around the circumference. The slightly larger inside diameter accommodates the Stub End, allowing for a secure fit and ensuring proper alignment within the piping system. Compared to Lap Joint Flanges, Backing Ring Flanges offer enhanced reinforcement and are easier to install, making them a preferred choice for various applications.
Why Choose Fortune Fittings Pvt. Ltd.?
With years of experience and expertise, Fortune Fittings Pvt. Ltd. is committed to delivering superior-quality products that exceed industry standards. Our team of skilled engineers and technicians ensures precise manufacturing and customization options to meet specific project requirements. We offer a comprehensive range of Backing Ring Flanges in different sizes and configurations, catering to diverse industrial needs.
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), Raise 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.
Conclusion
For premium-quality Backing Ring Flanges that guarantee superior support and reinforcement in piping systems, Fortune Fittings Pvt. Ltd. is your trusted partner. Contact us today to explore our extensive range of products and experience unparalleled customer service.
For the best prices and a wide selection of Backing Ring Flanges, visit our website or contact us directly. Trust Fortune Fittings Pvt. Ltd. for all your flange needs, and experience superior quality and service.
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