Weld neck flange RF is the most commonly used flange type which has safety and leak-proof connection. It is largely used in various industrial pipe system such as oil and gas, chemical, paper processing, power generation and sea water equipment.
Zizi is manufacturer of ASME B16.5 forged steel pipe fittings and offers Weld Neck Flange RF in different dimensions.
What is a Weld Neck Flange?
It is very easy to identify a weld neck flange from the appearance because it has a high, tapered hub like a neck. This neck will be welded with pipe so it has the same wall thickness as pipes. It also has the effect of dispersing pressure, making the pipe less deformable.
There are two designs for weld neck flange RF: a regular types we often used with pipes, the other is long hub type which is suitable for process plant.
Raised Face Weld Neck Flange resistant to extreme temperature,high pressure and withstand hostile environments. It is also a ideal choice when the media in pipeline is expensive, flammable or explosive.
What is Raised Face Flange?
Raised face is one kind of seal type of flanges, it means the gasket surface is higher than bolting circle face. This seal face is the most common used one not only among weld neck flanges. What’s more, the height of raised face is changing based on the diameter of flanges. By the way, the seal face is on the opposite of the hub side.
Weld Neck Flange B16.5 Dimensions & Material
Diameter: 1/2 to 24”
Pressure: Class 150, 300, 600, 900, 1500, 2500
Seal: RF (Raised Face), FF (Flat Face), RTJ (Ring Type Joint)
Schedule for Seal: Depends on wall thickness of pipes.
| Nominal Pipe Size | Outside Diameter (A) | Thickness (C) | Raised Face Diameter (G) | Length Thru Hub (D) | Point of Weld (E) | Hub Diameter (F) | Bore (B) | Approximate Weight (Ibs) | Bolt Circle (F) |
| 1/2 | 3.75 | 0.56 | 1.38 | 2.06 | 0.84 | 1.5 | Purchaser by purchaser | 2 | 2.63 |
| 3/4 | 4.63 | 0.63 | 1.69 | 2.25 | 1.05 | 1.88 | Purchaser by purchaser | 4 | 3.25 |
| 1 | 4.88 | 0.69 | 2 | 2.44 | 1.32 | 2.13 | Purchaser by purchaser | 4 | 3.5 |
| 11/4 | 5.25 | 0.81 | 2.5 | 2.63 | 1.66 | 2.5 | Purchaser by purchaser | 6 | 3.88 |
| 11/2 | 6.13 | 0.88 | 2.88 | 2.75 | 1.9 | 2.75 | Purchaser by purchaser | 8 | 4.5 |
| 2 | 6.5 | 1 | 3.63 | 2.88 | 2.38 | 3.31 | Purchaser by purchaser | 12 | 5 |
| 21/2 | 7.5 | 1.13 | 4.13 | 3.13 | 2.88 | 3.94 | Purchaser by purchaser | 18 | 5.88 |
| 3 | 8.25 | 1.25 | 5 | 3.25 | 3.5 | 4.63 | Purchaser by purchaser | 23 | 6.63 |
| 31/2 | 9 | 1.38 | 5.5 | 3.38 | 4 | 5.25 | Purchaser by purchaser | 26 | 7.25 |
| 4 | 10.75 | 1.5 | 6.19 | 4 | 4.5 | 6 | Purchaser by purchaser | 42 | 8.5 |
| 5 | 13 | 1.75 | 7.31 | 4.5 | 5.56 | 7.44 | Purchaser by purchaser | 68 | 10.5 |
| 6 | 14 | 1.88 | 8.5 | 4.63 | 6.63 | 8.75 | Purchaser by purchaser | 81 | 11.5 |
| 8 | 16.5 | 2.19 | 10.63 | 5.25 | 8.63 | 10.75 | Purchaser by purchaser | 120 | 13.75 |
| 10 | 20 | 2.5 | 12.75 | 6 | 10.75 | 13.5 | Purchaser by purchaser | 190 | 17 |
| 12 | 22 | 2.63 | 15 | 6.13 | 12.75 | 15.75 | Purchaser by purchaser | 225 | 19.25 |
| 14 | 23.75 | 2.75 | 16.25 | 6.5 | 14 | 17 | Purchaser by purchaser | 280 | 20.75 |
| 16 | 27 | 3 | 18.5 | 7 | 16 | 19.5 | Purchaser by purchaser | 390 | 23.75 |
| 18 | 29.25 | 3.25 | 21 | 7.25 | 18 | 21.5 | Purchaser by purchaser | 475 | 25.75 |
| 20 | 32 | 3.5 | 23 | 7.5 | 20 | 24 | Purchaser by purchaser | 590 | 28.5 |
| 22 | 34.25 | 3.75 | 25.25 | 7.75 | 22 | 26.25 | Purchaser by purchaser | 720 | 30.63 |
| 24 | 37 | 4 | 27.25 | 8 | 24 | 28.25 | Purchaser by purchaser | 830 | 33 |
Stainless Steel Raised Face Weld Neck Flange
ASTM A182 F304/304L, F306/316L, F309, F31, F317, F321, F347,F454L, ASTM A312/A403 TP304, TP304L, TP316, TP316L
Duplex & Super Duplex Steel Raised Face Weld Neck Flange
ASTM A 182 – F 51, F53, F55 S 31803, S 32205, S 32550, S 32750, S 32760, S 32950.
Carbon Steel Raised Face Weld Neck Flange
ASTM/ ASME A 105, ASTM/ ASME A 350 LF 2, ASTM / ASME A 53 GR. A & B, ASTM / ASME A 691, ASTM A 106 GR. A, B & C. API 5L GR. B, X 42, X 46, X 52, X 60, X 65
Alloy Steel Raised Face Weld Neck Flange
ASTM / ASME A 182, ASTM / ASME A 335 F1, F5, F9, F11, F12, F22, F23, F91, ASTM / ASME A 691 GR 1 CR, 1 1/4 CR, 2 1/4 CR, 5 CR, 9CR, 91
Copper Alloy Steel Raised Face Weld Neck Flange
ASTM / ASME SB 111 UNS NO. C10100 , C10200 , C10300 , C10800 , C12000, C12200, C70600 C71500, ASTM / ASME SB 466 UNS NO. C70600 , C71500
Nickel Alloy Raised Face Weld Neck Flange
ASTM / ASME SB 336, ASTM / ASME SB 564 / 160 / 163 / 472, NICKEL 200, NICKEL 201, MONEL 400 , ALLOY 20 / 20 CB 3, INCONEL825, INCONEL 600, INCONEL 601, INCONEL 625, HASTELLOY C 276
Weld Neck Flange Standard Specification
ASME B16.5
Size: 1/2 inch to 24 inches
Pressure: 150#, 300#, 600#, 900#, 1500#, 2500#
ASME B16.5 is a widely recognized and used standard published by the American Society of Mechanical Engineers (ASME). This standard covers pressure-temperature ratings, materials, dimensions, tolerances, marking, testing, and methods for specifying openings for pipe flanges and flanged fittings.
ASME B16.47A
Size: 26 inches to 60 inches
Pressure: 150#, 300#, 400#, 600#, 900#
ASME B16.47 A covers pressure-temperature ratings, materials, dimensions, tolerances, marking, and testing for large-diameter steel pipe flanges from NPS 26 to NPS 60. Compared to the B series, these flanges are typically thicker, heavier, and feature larger bolt circles and bolt sizes. They are generally considered more robust and capable of withstanding greater external loads.
ASME B16.47B
Size: 26 inches ~ 60 inches
Pressure: 75#, 150#, 300#, 400#, 600#, 900#
The ASME B16.47 standard covers two series of large-diameter steel flanges, one of which is ASME B16.47B, titled “Large Diameter Steel Flanges: NPS 26 to NPS 60 Metric/Inch Standard.” These flanges are typically lighter and thinner, with smaller bolt circles and bolt sizes, requiring more but smaller fasteners.
EN 1092-1
Size: DN 10 to DN 4000
Pressure: PN 2.5, 6, 10, 16, 25, 40, 63, 100, 160, 250, 400
EN 1092-1 is the European standard for steel circular flanges used to connect piping systems and equipment. This standard applies to flanges for pipes, valves, fittings, and other piping components, and is widely adopted in Europe and internationally.
JIS B2220
Size: 10A ~ 1500A
Pressure: 5K, 10K, 16K, 20K, 30K, 40K
JIS B2220 is a Japanese Industrial Standard (JIS) for steel pipe flanges. This standard is published by the Japanese Standards Association (JSA).
IN 2631 to DIN 2635
Size: DN 10 ~ DN 1000+
Pressure:
| DIN 2631 | DIN 2632 | DIN 2633 | DIN 2634 | DIN 2635 |
| PN 6 | PN 10 | PN 16 | PN 25 | PN 40 |
They are German Industrial Standard (DIN) that specifies welding neck flanges . This type of flange attaches to a piping system by butt welding the pipe directly to the flange neck. This design provides excellent stress distribution and is suitable for higher pressure and temperature applications.
Quality Control
As ISO certified company, we pay a great attentive on the quality. We take a standard inspection to guarantee the quality.
- Marking
- Surface
- Dimension
- Material (MTC)
Tack DN25 Class 600 ASTM A182 F304 Weld Neck Flange RF as an example.
- The marking should correct, clear and beautiful, such as “DN25 600# Weld Neck RF SS304 B16.5 831”.
- Hand touch and visual check to ensure the surface is even and smooth.
- Measure the outside diameter, thickness, raised face diameter and other values according to the dimension chart and compare those value with torelance.
- To prove the quality of material, we will offer you MTC (Mill Test Certificate) for every time.
