ASME B16.36 class 2500 welding neck orifice flange
The ASME B16.36 class 2500 welding neck orifice flange is a specialized component utilized in high-pressure piping systems for fluid flow measurement. This flange is designed in accordance with the ASME B16.36 standard, ensuring high performance, reliability, and safety in demanding industrial applications.
ASME B16.36 class 2500 welding neck orifice flange dimensions:

ASME B16.36 class 2500 welding neck orifice flange drawing
Nominal Pipe Size | R | O | tf | Y | Groove Number | Pitch Diameter,P | Groove Depth,E | Groove Width,F | Radius ar Bottom,r | Special Oval Ring Height,W | X | A | B | TT | Diameter of Bolt Circle | Number of Holes | Diameter of Holes | Diameter of Bolts | Raised Face | Ring Joint |
1 | 2.00 | 6.25 | 1.50 | 3.62 | R18 | 2.375 | 0.250 | 0.344 | 0.03 | 1.00 | 2.25 | 1.32 | To be specified by the purchaser | ¼ | 4.25 | 4 | 1.00 | 7/8 | 6.00 | 6.25 |
1½ | 2.88 | 8.00 | 1.75 | 4.38 | R23 | 3.250 | 0.312 | 0.469 | 0.03 | 1.06 | 3.12 | 1.90 | ¼ | 5.75 | 4 | 1.25 | 1⅛ | 7.00 | 7.50 | |
2 | 3.62 | 9.25 | 2.00 | 5.00 | R26 | 4.000 | 0.312 | 0.469 | 0.03 | 1.06 | 3.75 | 2.38 | ¼ | 6.75 | 8 | 1.12 | 1 | 7.25 | 7.75 | |
2½ | 4.12 | 10.50 | 2.25 | 5.62 | R28 | 4.375 | 0.375 | 0.531 | 0.06 | 1.19 | 4.50 | 2.88 | ¼ | 7.75 | 8 | 1.25 | 1⅛ | 8.00 | 8.50 | |
3 | 5.00 | 12.00 | 2.62 | 6.62 | R32 | 5.000 | 0.375 | 0.531 | 0.06 | 1.19 | 5.25 | 3.50 | ⅜ | 9.00 | 8 | 1.38 | 1¼ | 9.00 | 9.50 | |
4 | 6.19 | 14.00 | 3.00 | 7.50 | R38 | 6.188 | 0.438 | 0.656 | 0.06 | 1.31 | 6.50 | 4.50 | ½ | 10.75 | 8 | 1.62 | 1½ | 10.25 | 10.75 | |
6 | 8.50 | 19.00 | 4.25 | 10.75 | R47 | 9.000 | 0.500 | 0.781 | 0.06 | 1.44 | 9.25 | 6.63 | ½ | 14.50 | 8 | 2.12 | 2 | 13.75 | 14.50 | |
8 | 10.62 | 21.75 | 5.00 | 12.50 | R51 | 11.000 | 0.562 | 0.906 | 0.06 | 1.56 | 12.00 | 8.63 | ½ | 17.25 | 12 | 2.12 | 2 | 15.25 | 16.00 | |
10 | 12.75 | 26.50 | 6.50 | 16.50 | R55 | 13.500 | 0.688 | 1.188 | 0.09 | 1.88 | 14.75 | 10.75 | ½ | 21.25 | 12 | 2.62 | 2½ | 19.25 | 20.25 | |
12 | 15.00 | 30.00 | 7.25 | 18.25 | R60 | 16.000 | 0.688 | 1.312 | 0.09 | 2.00 | 17.38 | 12.75 | ½ | 24.38 | 12 | 2.88 | 2¾ | 21.25 | 22.50 |
GENERAL NOTES:
(a)Dimensions are in inches.
(b)All other dimensions are in accordance with ASME B16.5.
(c)Ring joint flanges larger than NPS 3 will require angular meter taps as shown in Fig.2.

Fig.2 Angular Meter Tap for RTJ Flanges
NOTES:
(1)Other NPT sizes may be furnished if required.
(2)In conformance with ASME B16.5,stud bolt lengths do not include point heights.
(3)Bolt lengths for raised face flanges include allowance for orifice and gasket thickness of 0.25 in.for NPS 1 to NPS 12.Bolt lengths for ring-type joint flanges include allowance of 0.62 in.for NPS 1 to NPS 3.
The ASME B16.36 class 2500 welding neck orifice flange is a vital component in high-pressure piping systems, providing robust and reliable solutions for fluid measurement applications. Its adherence to strict industry standards, combined with its durable design and high-pressure capabilities, makes it an excellent choice for engineers and industry professionals seeking optimal performance in demanding environments.
ASME B16.36 Class 2500 welding neck orifice flanges are available in a variety of materials to suit different operating environments, including:
- Carbon steel (e.g., ASTM A105)
- Stainless steel (e.g., ASTM A182 F304, F316)
- Alloy steels for more extreme environments, including high-temperature or corrosive conditions.
Material selection is based on factors such as temperature, pressure, and the chemical nature of the fluid being processed.
ASME B16.36 class 2500 welding neck orifice flanges are used in industries that require high-pressure fluid control and flow measurement, including:
- Oil and gas (e.g., refineries, pipelines)
- Petrochemical and chemical processing
- Power generation
- Water treatment
They are particularly suited for high-pressure systems that need reliable and accurate flow measurement of liquids, gases, or steam.
Haihao Group can provide a variety orifice flange,as follows:
- ASME B16.36 class 300 welding neck orifice flange
- ASME B16.36 class 300 slip on orifice flange
- ASME B16.36 class 300 threaded orifice flange
- ASME B16.36 class 400 welding neck orifice flange
- ASME B16.36 class 600 welding neck orifice flange
- ASME B16.36 class 900 welding neck orifice flange
- ASME B16.36 class 1500 welding neck orifice flange
- ASME B16.36 class 2500 welding neck orifice flange
Haihao Group manufacture & supply & export pipeline products more than 30 years,which contain butt welding pipe fittings(elbows,tees,reducers,caps,bends,crosses,etc),forged pipe fittings(socket weld/threaded elbows, tees, reducers, crosses, couplings, union, outlet, nipple, etc),steel pipes(seamless steel pipes, SAW/ERW steel pipes, casing and tubing pipes,etc) and forged flanges(weld neck flange, slip on flange, blind flange, lap joint flange, plate flange, threaded flange, socket weld flange, orifice flange, spectacle blind flange, weld overlay cladding flange,etc).We supply the products in different standards such as ANSI/ASME, ASTM, BS, EN, JIS, GOST, ISO, MSS, etc.If you want to know more about our pipeline products,please email us:sales@haihaogroup.com