ASME/ANSI B16.47 Series A Weld Neck Flange
Our company provides ASME/ANSI B16.47 Flange Series A Weld Neck Flange.
The ASME/ANSI B16.47 Flange Series A Weld Neck Flange is a type of flange designed for use in high-pressure and high-temperature applications. It conforms to the requirements of the ASME/ANSI B16.47 Series A standard, which covers large-diameter steel flanges that range from NPS 26 through NPS 60 (nominal pipe size).
lewis Liu
sales Manager
ASME/ANSI B16.47 Flange Series A Weld Neck Flange
ASME/ANSI B16.47 Class 150 Series A Welding Neck Flanges
(A)All dimensions are in inches.
(B)These flanges will be furnished with a 1/16″ raised face unless otherwise specified. For more alternate flange facings, please click here!
(C)Standard Bore will be furnished unless otherwise specified. For more diameter of holes, please click here!
| Nominal Pipe Size | Outside Diameter (O) | Bolt Circle (W) | Raised Face Diameter (R) | Number of Holes | Diameter of Holes | Bore (B) | Top of Hub (A) | Hub Diameter (X) | Minimum Fillet Radius (r) | Minimum Thickness (T) | Length Thru Hub (Y) | Approximate Weight (lbs) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 26 | 34.25 | 31.75 | 29.50 | 24 | 1.38 | Specified by purchaser | 26.00 | 26.62 | 0.38 | 2.69 | 4.75 | 300 |
| 28 | 36.50 | 34.00 | 31.50 | 28 | 1.38 | Specified by purchaser | 28.00 | 28.62 | 0.44 | 2.81 | 4.94 | 345 |
| 30 | 38.75 | 36.00 | 33.75 | 28 | 1.38 | Specified by purchaser | 30.00 | 30.75 | 0.44 | 2.94 | 5.38 | 400 |
| 32 | 41.75 | 38.50 | 36.00 | 28 | 1.62 | Specified by purchaser | 32.00 | 32.75 | 0.44 | 3.19 | 5.69 | 505 |
| 34 | 43.75 | 40.50 | 38.00 | 32 | 1.62 | Specified by purchaser | 34.00 | 34.75 | 0.50 | 3.25 | 5.88 | 540 |
| 36 | 46.00 | 42.75 | 40.25 | 32 | 1.62 | Specified by purchaser | 36.00 | 36.75 | 0.50 | 3.56 | 6.19 | 640 |
| 38 | 48.75 | 45.25 | 42.25 | 32 | 1.62 | Specified by purchaser | 38.00 | 39.00 | 0.50 | 3.44 | 6.19 | 720 |
| 40 | 50.75 | 47.25 | 44.25 | 36 | 1.62 | Specified by purchaser | 40.00 | 41.00 | 0.50 | 3.56 | 6.44 | 775 |
| 42 | 53.00 | 49.50 | 47.00 | 36 | 1.62 | Specified by purchaser | 42.00 | 43.00 | 0.50 | 3.81 | 6.75 | 890 |
| 44 | 55.25 | 51.75 | 49.00 | 40 | 1.62 | Specified by purchaser | 44.00 | 45.00 | 0.50 | 4.00 | 7.00 | 990 |
| 46 | 57.25 | 53.75 | 51.00 | 40 | 1.62 | Specified by purchaser | 46.00 | 47.12 | 0.50 | 4.06 | 7.31 | 1060 |
| 48 | 59.50 | 56.00 | 53.50 | 44 | 1.62 | Specified by purchaser | 48.00 | 49.12 | 0.50 | 4.25 | 7.56 | 1185 |
| 50 | 61.75 | 58.25 | 55.50 | 44 | 1.88 | Specified by purchaser | 50.00 | 51.25 | 0.50 | 4.38 | 8.00 | 1270 |
| 52 | 64.00 | 60.50 | 57.50 | 44 | 1.88 | Specified by purchaser | 52.00 | 53.25 | 0.50 | 4.56 | 8.25 | 1410 |
| 54 | 66.25 | 62.75 | 59.50 | 44 | 1.88 | Specified by purchaser | 54.00 | 55.25 | 0.50 | 4.75 | 8.50 | 1585 |
| 56 | 68.75 | 65.00 | 62.00 | 48 | 1.88 | Specified by purchaser | 56.00 | 57.38 | 0.50 | 4.88 | 9.00 | 1760 |
| 58 | 71.00 | 67.25 | 64.00 | 48 | 1.88 | Specified by purchaser | 58.00 | 59.38 | 0.50 | 5.06 | 9.25 | 1915 |
| 60 | 73.00 | 69.25 | 66.00 | 52 | 1.88 | Specified by purchaser | 60.00 | 61.38 | 0.50 | 5.19 | 9.44 | 2045 |
ASME/ANSI B16.47 Class 300 Series A Welding Neck Flanges
(A)All dimensions are in inches.
(B)These flanges will be furnished with a 1/16″ raised face unless otherwise specified. For more alternate flange facings, please click here!
(C)Standard Bore will be furnished unless otherwise specified. For more diameter of holes, please click here!
| Nominal Pipe Size | Outside Diameter (O) | Bolt Circle (W) | Raised Face Diameter (R) | Number of Holes | Diameter of Holes | Bore (B) | Top of Hub (A) | Hub Diameter (X) | Minimum Fillet Radius (r) | Minimum Thickness (T) | Length Thru Hub (Y) | Approximate Weight (lbs) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 26 | 38.25 | 34.50 | 29.50 | 28 | 1.75 | Specified by purchaser | 26.00 | 28.38 | 0.38 | 3.12 | 7.25 | 605 |
| 28 | 40.75 | 37.00 | 31.50 | 28 | 1.75 | Specified by purchaser | 28.00 | 30.50 | 0.44 | 3.38 | 7.75 | 745 |
| 30 | 43.00 | 39.25 | 33.75 | 28 | 1.88 | Specified by purchaser | 30.00 | 32.56 | 0.44 | 3.62 | 8.25 | 870 |
| 32 | 45.25 | 41.50 | 36.00 | 28 | 2.00 | Specified by purchaser | 32.00 | 34.69 | 0.44 | 3.88 | 8.75 | 1005 |
| 34 | 47.50 | 43.50 | 38.00 | 28 | 2.00 | Specified by purchaser | 34.00 | 36.88 | 0.50 | 4.00 | 9.12 | 1145 |
| 36 | 50.00 | 46.00 | 40.25 | 32 | 2.12 | Specified by purchaser | 36.00 | 39.00 | 0.50 | 4.12 | 9.50 | 1275 |
| 38 | 46.00 | 43.00 | 40.50 | 32 | 1.62 | Specified by purchaser | 38.00 | 39.12 | 0.50 | 4.25 | 7.12 | 695 |
| 40 | 48.75 | 45.50 | 42.75 | 32 | 1.75 | Specified by purchaser | 40.00 | 41.25 | 0.50 | 4.50 | 7.62 | 840 |
| 42 | 50.75 | 47.50 | 44.75 | 32 | 1.75 | Specified by purchaser | 42.00 | 43.25 | 0.50 | 4.69 | 7.88 | 950 |
| 44 | 53.25 | 49.75 | 47.00 | 32 | 1.88 | Specified by purchaser | 44.00 | 45.25 | 0.50 | 4.88 | 8.12 | 1055 |
| 46 | 55.75 | 52.00 | 49.00 | 28 | 2.00 | Specified by purchaser | 46.00 | 47.38 | 0.50 | 5.06 | 8.50 | 1235 |
| 48 | 57.75 | 54.00 | 51.25 | 32 | 2.00 | Specified by purchaser | 48.00 | 49.38 | 0.50 | 5.25 | 8.81 | 1380 |
| 50 | 60.25 | 56.25 | 53.50 | 32 | 2.12 | Specified by purchaser | 50.00 | 51.38 | 0.50 | 5.50 | 9.12 | 1530 |
| 52 | 62.25 | 58.25 | 55.50 | 32 | 2.12 | Specified by purchaser | 52.00 | 53.38 | 0.50 | 5.69 | 9.38 | 1660 |
| 54 | 65.25 | 61.00 | 57.75 | 28 | 2.38 | Specified by purchaser | 54.00 | 55.50 | 0.50 | 6.00 | 9.94 | 2050 |
| 56 | 67.25 | 63.00 | 59.75 | 28 | 2.38 | Specified by purchaser | 56.00 | 57.62 | 0.50 | 6.06 | 10.25 | 2155 |
| 58 | 69.25 | 65.00 | 62.00 | 32 | 2.38 | Specified by purchaser | 58.00 | 59.62 | 0.50 | 6.25 | 10.50 | 2270 |
| 60 | 71.25 | 67.00 | 64.00 | 32 | 2.38 | Specified by purchaser | 60.00 | 61.62 | 0.50 | 6.44 | 10.75 | 2470 |
ASME/ANSI B16.47 Class 400 Series A Welding Neck Flanges
(a)All dimensions are in inches.
(b)These flanges will be furnished with a 1/4″ raised face unless otherwise specified. For more alternate flange facings, please click here!
| Nominal Pipe Size | Outside Diameter (O) | Bolt Circle (W) | Raised Face Diameter (R) | Number of Holes | Diameter of Holes | Bore (B) | Top of Hub (A) | Hub Diameter (X) | Minimum Fillet Radius (r) | Minimum Thickness (T) | Length Thru Hub (Y) | Approximate Weight (lbs) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 26 | 38.25 | 34.50 | 29.50 | 28 | 1.88 | Specified by purchaser | 26.00 | 28.62 | 0.44 | 3.50 | 7.62 | 650 |
| 28 | 40.75 | 37.00 | 31.50 | 28 | 2.00 | Specified by purchaser | 28.00 | 30.81 | 0.50 | 3.75 | 8.12 | 785 |
| 30 | 43.00 | 39.25 | 33.75 | 28 | 2.12 | Specified by purchaser | 30.00 | 32.94 | 0.50 | 4.00 | 8.62 | 905 |
| 32 | 45.25 | 41.50 | 36.00 | 28 | 2.12 | Specified by purchaser | 32.00 | 35.00 | 0.50 | 4.25 | 9.12 | 1065 |
| 34 | 47.50 | 43.50 | 38.00 | 28 | 2.12 | Specified by purchaser | 34.00 | 37.19 | 0.56 | 4.38 | 9.50 | 1200 |
| 36 | 50.00 | 46.00 | 40.25 | 32 | 2.12 | Specified by purchaser | 36.00 | 39.38 | 0.56 | 4.50 | 9.88 | 1340 |
| 38 | 47.50 | 44.00 | 40.75 | 32 | 1.88 | Specified by purchaser | 38.00 | 39.50 | 0.56 | 4.88 | 8.12 | 935 |
| 40 | 50.00 | 46.25 | 43.00 | 32 | 2.00 | Specified by purchaser | 40.00 | 41.50 | 0.56 | 5.12 | 8.50 | 1090 |
| 42 | 52.00 | 48.25 | 45.00 | 32 | 2.00 | Specified by purchaser | 42.00 | 43.62 | 0.56 | 5.25 | 8.81 | 1190 |
| 44 | 54.50 | 50.50 | 47.25 | 32 | 2.12 | Specified by purchaser | 44.00 | 45.62 | 0.56 | 5.50 | 9.18 | 1375 |
| 46 | 56.75 | 52.75 | 49.50 | 36 | 2.12 | Specified by purchaser | 46.00 | 47.75 | 0.56 | 5.75 | 9.62 | 1525 |
| 48 | 59.50 | 55.25 | 51.50 | 28 | 2.38 | Specified by purchaser | 48.00 | 49.88 | 0.56 | 6.00 | 10.12 | 1790 |
| 50 | 61.75 | 57.50 | 53.62 | 32 | 2.38 | Specified by purchaser | 50.00 | 52.00 | 0.56 | 6.19 | 10.56 | 1950 |
| 52 | 63.75 | 59.50 | 55.62 | 32 | 2.38 | Specified by purchaser | 52.00 | 54.00 | 0.56 | 6.38 | 10.88 | 2125 |
| 54 | 67.00 | 62.25 | 57.88 | 28 | 2.62 | Specified by purchaser | 54.00 | 56.12 | 0.56 | 6.69 | 11.38 | 2565 |
| 56 | 69.00 | 64.25 | 60.12 | 32 | 2.62 | Specified by purchaser | 56.00 | 58.25 | 0.56 | 6.88 | 11.75 | 2710 |
| 58 | 71.00 | 66.25 | 62.12 | 32 | 2.62 | Specified by purchaser | 58.00 | 60.25 | 0.56 | 7.00 | 12.06 | 3230 |
| 60 | 74.25 | 69.00 | 64.38 | 32 | 2.88 | Specified by purchaser | 60.00 | 62.38 | 0.56 | 7.31 | 12.56 | 3820 |
ASME/ANSI B16.47 Class 600 Series A Welding Neck Flanges
(a)All dimensions are in inches.
(b)These flanges will be furnished with a 1/4″ raised face unless otherwise specified. For more alternate flange facings, please click here!
| Nominal Pipe Size | Outside Diameter (O) | Bolt Circle (W) | Raised Face Diameter (R) | Number of Holes | Diameter of Holes | Bore (B) | Top of Hub (A) | Hub Diameter (X) | Minimum Fillet Radius (r) | Minimum Thickness (T) | Length Thru Hub (Y) | Approximate Weight (lbs) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 26 | 40.00 | 36.00 | 29.50 | 28 | 2.00 | Specified by purchaser | 26.00 | 29.44 | 0.50 | 4.25 | 8.75 | 940 |
| 28 | 42.25 | 38.00 | 31.50 | 28 | 2.12 | Specified by purchaser | 28.00 | 31.62 | 0.50 | 4.38 | 9.25 | 1060 |
| 30 | 44.50 | 40.25 | 33.75 | 28 | 2.12 | Specified by purchaser | 30.00 | 33.94 | 0.50 | 4.50 | 9.75 | 1210 |
| 32 | 47.00 | 42.50 | 36.00 | 28 | 2.38 | Specified by purchaser | 32.00 | 36.12 | 0.50 | 4.62 | 10.25 | 1375 |
| 34 | 49.00 | 44.50 | 38.00 | 28 | 2.38 | Specified by purchaser | 34.00 | 38.31 | 0.56 | 4.75 | 10.62 | 1540 |
| 36 | 51.75 | 47.00 | 40.25 | 28 | 2.62 | Specified by purchaser | 36.00 | 40.62 | 0.56 | 4.88 | 11.12 | 1705 |
| 38 | 50.00 | 45.75 | 41.50 | 28 | 2.38 | Specified by purchaser | 38.00 | 40.25 | 0.56 | 6.00 | 10.00 | 1470 |
| 40 | 52.00 | 47.75 | 43.75 | 32 | 2.38 | Specified by purchaser | 40.00 | 42.25 | 0.56 | 6.25 | 10.38 | 1630 |
| 42 | 55.25 | 50.50 | 46.00 | 28 | 2.62 | Specified by purchaser | 42.00 | 44.38 | 0.56 | 6.62 | 11.00 | 2030 |
| 44 | 57.25 | 52.50 | 48.25 | 32 | 2.62 | Specified by purchaser | 44.00 | 46.50 | 0.56 | 6.81 | 11.38 | 2160 |
| 46 | 59.50 | 54.75 | 50.25 | 32 | 2.62 | Specified by purchaser | 46.00 | 48.62 | 0.56 | 7.06 | 11.81 | 2410 |
| 48 | 62.75 | 57.50 | 52.50 | 32 | 2.88 | Specified by purchaser | 48.00 | 50.75 | 0.56 | 7.44 | 12.44 | 2855 |
| 50 | 65.75 | 60.00 | 54.50 | 28 | 3.12 | Specified by purchaser | 50.00 | 52.88 | 0.56 | 7.75 | 12.94 | 3330 |
| 52 | 67.75 | 62.00 | 56.50 | 32 | 3.12 | Specified by purchaser | 52.00 | 54.88 | 0.56 | 8.00 | 13.25 | 3560 |
| 54 | 70.00 | 64.25 | 58.75 | 32 | 3.12 | Specified by purchaser | 54.00 | 57.00 | 0.56 | 8.25 | 13.75 | 3920 |
| 56 | 73.00 | 66.75 | 60.75 | 32 | 3.38 | Specified by purchaser | 56.00 | 59.12 | 0.62 | 8.56 | 14.25 | 4280 |
| 58 | 75.00 | 68.75 | 63.00 | 32 | 3.38 | Specified by purchaser | 58.00 | 61.12 | 0.62 | 8.75 | 14.56 | 4640 |
| 60 | 78.50 | 71.75 | 65.25 | 28 | 3.62 | Specified by purchaser | 60.00 | 63.38 | 0.69 | 9.19 | 15.31 | 5000 |
ASME/ANSI B16.47 Class 900 Series A Welding Neck Flanges
(a)All dimensions are in inches.
(b)These flanges will be furnished with a 1/4″ raised face unless otherwise specified. For more alternate flange facings, please click here!
| Nominal Pipe Size | Outside Diameter (O) | Bolt Circle (W) | Raised Face Diameter (R) | Number of Holes | Diameter of Holes | Bore (B) | Top of Hub (A) | Hub Diameter (X) | Minimum Fillet Radius (r) | Minimum Thickness (T) | Length Thru Hub (Y) | Approximate Weight (lbs) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 26 | 42.75 | 37.50 | 29.50 | 20 | 2.88 | Specified by purchaser | 26.00 | 30.50 | 0.44 | 5.50 | 11.25 | 1525 |
| 28 | 46.00 | 40.25 | 31.50 | 20 | 3.12 | Specified by purchaser | 28.00 | 32.75 | 0.50 | 5.62 | 11.75 | 1810 |
| 30 | 48.50 | 42.75 | 33.75 | 20 | 3.12 | Specified by purchaser | 30.00 | 35.00 | 0.50 | 5.88 | 12.25 | 2120 |
| 32 | 51.75 | 45.50 | 36.00 | 20 | 3.38 | Specified by purchaser | 32.00 | 37.25 | 0.50 | 6.25 | 13.00 | 2545 |
| 34 | 55.00 | 48.25 | 38.00 | 20 | 3.62 | Specified by purchaser | 34.00 | 39.62 | 0.56 | 6.50 | 13.75 | 2970 |
| 36 | 57.50 | 50.75 | 40.25 | 20 | 3.62 | Specified by purchaser | 36.00 | 41.88 | 0.56 | 6.75 | 14.25 | 3395 |
| 38 | 57.50 | 50.75 | 43.25 | 20 | 3.62 | Specified by purchaser | 38.00 | 42.25 | 0.75 | 7.50 | 13.88 | 3385 |
| 40 | 59.50 | 52.75 | 45.75 | 24 | 3.62 | Specified by purchaser | 40.00 | 44.38 | 0.81 | 7.75 | 14.31 | 3620 |
| 42 | 61.50 | 54.75 | 47.75 | 24 | 3.62 | Specified by purchaser | 42.00 | 46.31 | 0.81 | 8.12 | 14.62 | 3960 |
| 44 | 64.88 | 57.62 | 50.00 | 24 | 3.88 | Specified by purchaser | 44.00 | 48.62 | 0.88 | 8.44 | 15.38 | 4300 |
| 46 | 68.25 | 60.50 | 52.50 | 24 | 4.12 | Specified by purchaser | 46.00 | 50.88 | 0.88 | 8.88 | 16.18 | 4640 |
| 48 | 70.25 | 62.50 | 54.50 | 24 | 4.12 | Specified by purchaser | 48.00 | 52.88 | 0.94 | 9.19 | 16.50 | 4980 |
ASME/ANSI B16.47 Series A Weld Neck Flanges Main Features and Specifications Table
Here is a table outlining the specifications and characteristics of ASME/ANSI B16.47 Series A Weld Neck Flanges:
| Specification/Feature | Description |
|---|---|
| Standard | ASME/ANSI B16.47 Series A Weld Neck Flange. |
| Type | Weld Neck Flange – A type of flange with a long tapered neck that is butt-welded to the pipe, providing excellent strength and stress distribution. |
| Pressure Rating | Available in various pressure ratings, such as 150, 300, 600, 900, etc., depending on the application requirements. |
| Size Range | Typically available in a wide range of sizes to accommodate different pipe and equipment dimensions. |
| Material | Can be manufactured from a variety of materials, including carbon steel, stainless steel, alloy steel, etc., chosen based on application requirements. |
| Facing Type | Series A Weld Neck Flanges typically have Raised Face (RF) facing, which provides a reliable sealing surface. |
| Bolt Hole Quantity and Diameter | The number and diameter of bolt holes vary with flange size and pressure rating, facilitating flange connection. |
| Seal Type | Series A Weld Neck Flanges commonly use gaskets or O-rings for sealing. |
| Performance Characteristics | Known for their high-pressure-bearing capacity, durability, and suitability for critical applications. |
| Application Areas | Widely used in industries such as oil and gas, petrochemical, power generation, and more for connecting high-pressure piping systems. |
| Manufacturing Standards | Manufactured in compliance with ASME/ANSI B16.47 Series A standard and relevant ASME codes. |
This table provides a comprehensive overview of ASME/ANSI B16.47 Series A Weld Neck Flanges, including their specifications, characteristics, and application areas. Specific requirements may vary depending on the chosen flange size, pressure rating, and material.
Characteristics:
ASME B16 47 Series A flanges are much heavier, thicker, and more robust than Series B flanges with the same pressure rating and size. Hence, series A flanges can easily withstand extra external loading than Series B flanges.
The ASME/ANSI B16.47 Flange Series A Weld Neck Flange is a type of flange designed for use in high-pressure and high-temperature applications. It conforms to the requirements of the ASME/ANSI B16.47 Series A standard, which covers large-diameter steel flanges that range from NPS 26 through NPS 60 (nominal pipe size).
Weld neck flanges are designed with a long tapered hub that is welded to a pipe or fitting, and they are used to provide a strong, reliable connection between two sections of piping or equipment. The hub of the weld neck flange is designed to withstand high stresses, and it provides reinforcement to the connection point.
The ASME/ANSI B16.47 Series A standard specifies the dimensions, tolerances, materials, and testing requirements for these flanges. The standard provides detailed dimensions for the weld neck flange hub, as well as for the bolt holes, gasket surface, and other critical features of the flange.
One of the key benefits of Series A weld neck flanges is their ability to provide a strong and reliable connection in high-pressure and high-temperature applications. The flanges are designed to withstand extreme conditions, and they are often used in critical applications such as oil and gas pipelines, chemical processing, and power generation.
In addition to their strength and durability, Series A weld neck flanges are also easy to install and maintain. They can be quickly welded to the end of a pipe or fitting, and they are designed to be easy to remove and replace as needed. This makes them an ideal solution for pipelines and equipment that require frequent maintenance or repair.
In summary, ASME/ANSI B16.47 Flange Series A Weld Neck Flanges are a type of flange that conform to the requirements of the ASME/ANSI B16.47 Series A standard. They are designed for use in high-pressure and high-temperature applications and are commonly used in the oil and gas, chemical processing, and power generation industries. These flanges provide a strong and reliable connection between two sections of piping or equipment and are easy to install and maintain.
Required Fasteners:
The fastener quality requirement for ASME B16.47 Series A flanges is less than for Series A. Class 150 series A flange needs 28 bolts with sizes of 1-1/4-inch diameter to install. The total number of fasteners for ASME B16.47 Series B flanges is higher than for Series A. For class 150 Series B flange needs 44 bolts with a diameter of 3/ 4 inches diameter to install. The smaller bolt circle width affects the movement of the flange after installation.
Types:
Series A and Series B standards include blind flanges as well as weld neck flanges in raised face type (RF). But Series A illustrates ring-type joint (RTJ) flanges with the different classes such as from Class 300 to Class 900.
Cost:
The cost of ASME B16.47 Series A flanges is more than ASME B16.47 Series B flanges.
Use:
Series A flanges are perfect for many piping end users for the new pipeline or connections. Series B flanges are perfect for refurbishment or replacement work and also for non-critical piping applications. In industry, Series A flanges are suitable for all complex applications, but Series B flanges are only suitable for easy applications.
Weight of Flange:
ASME B16.47 Series A flanges are heavier, and hence they can so exert more extra weight on piping supports. The weight of ASME B16.47 Series B flanges is comparatively less and therefore cannot sustain in high load.
Pressure class 75:
This unique pressure class is available in ASME B16.47 Series B flanges but not available in ASME B16.47 Series A flanges.
Dimensions:
The dimension of Series A flanges is larger because the bolt circle diameter, flange outer diameter, bolt diameter, flange thickness, etc., are larger. But Series A flanges are compact in dimension as compared to series A flanges.