Below is a comprehensive guide and dimension chart for 347H flanges manufactured under the ASME B16.5 standard, covering NPS 1/2 to NPS 24.
Understanding the ASME B16.5 Standard for 347H
ASME B16.5 covers Pipe Flanges and Flanged Fittings from NPS 1/2 through NPS 24. It specifies requirements for various pressure classes: 150, 300, 400, 600, 900, 1500, and 2500. For 347H applications, the most common classes are 150, 300, and 600, though high-pressure refinery applications often require 900 and above.
When ordering 347H flanges, specifying the correct dimensions is vital. A mismatch in bolt hole diameter or bolt circle can halt installation entirely. Our factory adheres strictly to these tolerances. The following tables provide the critical dimensional data required for procurement and engineering verification.
Steel 347h Flange Dimensions Chart
To ensure clarity and rigor, we have divided the data into two sections: Lower Pressure Classes (150, 300, 600) and Higher Pressure Classes (900, 1500, 2500). All dimensions are in inches.
Table 1: ASME B16.5 Dimensions for Classes 150, 300, and 600
|
NPS |
Outside Diameter (O) |
Bolt Circle (BC) |
Bolt Holes (No. x Dia) |
Thickness (T) approx. |
||||||||
|
150 |
300 |
600 |
150 |
300 |
600 |
150 |
300 |
600 |
150 |
300 |
600 |
|
|
1/2 |
3.50 |
3.75 |
3.75 |
2.38 |
2.62 |
2.62 |
4 x 5/8 |
4 x 5/8 |
4 x 5/8 |
0.44 |
0.50 |
0.56 |
|
3/4 |
3.88 |
4.62 |
4.62 |
2.75 |
3.25 |
3.25 |
4 x 5/8 |
4 x 3/4 |
4 x 3/4 |
0.44 |
0.56 |
0.62 |
|
1 |
4.25 |
4.88 |
4.88 |
3.12 |
3.50 |
3.50 |
4 x 5/8 |
4 x 3/4 |
4 x 3/4 |
0.44 |
0.62 |
0.69 |
|
1 1/4 |
4.62 |
5.38 |
5.38 |
3.50 |
3.88 |
3.88 |
4 x 5/8 |
4 x 3/4 |
4 x 3/4 |
0.44 |
0.69 |
0.75 |
|
1 1/2 |
5.00 |
6.12 |
6.12 |
3.88 |
4.50 |
4.50 |
4 x 5/8 |
4 x 7/8 |
4 x 7/8 |
0.44 |
0.75 |
0.81 |
|
2 |
6.00 |
6.50 |
6.50 |
4.75 |
5.00 |
5.00 |
4 x 3/4 |
4 x 7/8 |
4 x 7/8 |
0.44 |
0.81 |
0.88 |
|
2 1/2 |
7.00 |
7.50 |
7.50 |
5.50 |
5.88 |
5.88 |
4 x 3/4 |
4 x 7/8 |
4 x 7/8 |
0.44 |
0.88 |
0.94 |
|
3 |
7.50 |
8.25 |
8.25 |
6.00 |
6.62 |
6.62 |
4 x 3/4 |
4 x 7/8 |
4 x 1 |
0.44 |
0.94 |
1.00 |
|
4 |
9.00 |
9.00 |
9.00 |
7.50 |
7.88 |
7.88 |
8 x 3/4 |
8 x 7/8 |
8 x 1 |
0.44 |
1.00 |
1.06 |
|
5 |
10.00 |
10.00 |
10.00 |
8.50 |
8.50 |
8.50 |
8 x 3/4 |
8 x 7/8 |
8 x 1 |
0.44 |
1.06 |
1.12 |
|
6 |
11.00 |
11.00 |
11.00 |
9.50 |
9.50 |
9.50 |
8 x 3/4 |
8 x 7/8 |
8 x 1 |
0.44 |
1.12 |
1.19 |
|
8 |
13.50 |
13.50 |
13.50 |
11.75 |
11.75 |
11.75 |
8 x 7/8 |
8 x 1 |
8 x 1 1/8 |
0.44 |
1.19 |
1.31 |
|
10 |
16.00 |
16.00 |
16.00 |
14.25 |
14.25 |
14.25 |
12 x 7/8 |
12 x 1 |
12 x 1 1/4 |
0.44 |
1.25 |
1.44 |
|
12 |
19.00 |
19.00 |
19.00 |
17.00 |
17.00 |
17.00 |
12 x 7/8 |
12 x 1 |
12 x 1 3/8 |
0.44 |
1.31 |
1.56 |
|
14 |
21.00 |
21.00 |
21.00 |
18.75 |
18.75 |
18.75 |
12 x 1 |
12 x 1 1/8 |
12 x 1 1/2 |
0.50 |
1.38 |
1.69 |
|
16 |
23.50 |
23.50 |
23.50 |
21.25 |
21.25 |
21.25 |
16 x 1 |
16 x 1 1/8 |
16 x 1 5/8 |
0.50 |
1.44 |
1.81 |
|
18 |
25.00 |
25.00 |
25.00 |
22.75 |
22.75 |
22.75 |
16 x 1 1/8 |
16 x 1 1/4 |
16 x 1 3/4 |
0.50 |
1.50 |
1.94 |
|
20 |
27.50 |
27.50 |
27.50 |
25.00 |
25.00 |
25.00 |
20 x 1 1/8 |
20 x 1 1/4 |
20 x 1 7/8 |
0.50 |
1.56 |
2.06 |
|
24 |
32.00 |
32.00 |
32.00 |
29.50 |
29.50 |
29.50 |
20 x 1 1/4 |
20 x 1 3/8 |
20 x 2 |
0.50 |
1.69 |
2.31 |
Table 2: ASME B16.5 Dimensions for Classes 900, 1500, and 2500
|
NPS |
Outside Diameter (O) |
Bolt Circle (BC) |
Bolt Holes (No. x Dia) |
Thickness (T) approx. |
||||||||
|
900 |
1500 |
2500 |
900 |
1500 |
2500 |
900 |
1500 |
2500 |
900 |
1500 |
2500 |
|
|
1/2 |
3.75 |
3.75 |
3.75 |
2.62 |
2.62 |
2.62 |
4 x 3/4 |
4 x 3/4 |
4 x 3/4 |
0.62 |
0.62 |
0.62 |
|
3/4 |
4.62 |
4.62 |
4.62 |
3.25 |
3.25 |
3.25 |
4 x 7/8 |
4 x 7/8 |
4 x 7/8 |
0.69 |
0.69 |
0.75 |
|
1 |
4.88 |
4.88 |
4.88 |
3.50 |
3.50 |
3.50 |
4 x 7/8 |
4 x 7/8 |
4 x 7/8 |
0.75 |
0.81 |
0.88 |
|
1 1/4 |
5.38 |
5.38 |
5.38 |
3.88 |
3.88 |
3.88 |
4 x 7/8 |
4 x 7/8 |
4 x 7/8 |
0.81 |
0.88 |
1.00 |
|
1 1/2 |
6.12 |
6.12 |
6.12 |
4.50 |
4.50 |
4.50 |
4 x 7/8 |
4 x 7/8 |
4 x 7/8 |
0.88 |
0.94 |
1.12 |
|
2 |
6.50 |
6.50 |
6.50 |
5.00 |
5.00 |
5.00 |
4 x 7/8 |
4 x 7/8 |
4 x 7/8 |
0.94 |
1.00 |
1.25 |
|
2 1/2 |
7.50 |
7.50 |
7.50 |
5.88 |
5.88 |
5.88 |
4 x 7/8 |
4 x 7/8 |
4 x 7/8 |
1.00 |
1.06 |
1.38 |
|
3 |
8.25 |
8.25 |
8.25 |
6.62 |
6.62 |
6.62 |
4 x 1 |
4 x 1 |
4 x 1 |
1.06 |
1.12 |
1.50 |
|
4 |
9.00 |
9.00 |
9.00 |
7.88 |
7.88 |
7.88 |
8 x 1 |
8 x 1 |
8 x 1 |
1.12 |
1.25 |
1.62 |
|
5 |
10.00 |
10.00 |
10.00 |
8.50 |
8.50 |
8.50 |
8 x 1 |
8 x 1 |
8 x 1 |
1.19 |
1.31 |
1.75 |
|
6 |
11.00 |
11.00 |
11.00 |
9.50 |
9.50 |
9.50 |
8 x 1 |
8 x 1 |
8 x 1 |
1.25 |
1.38 |
1.88 |
|
8 |
13.50 |
13.50 |
13.50 |
11.75 |
11.75 |
11.75 |
8 x 1 1/8 |
8 x 1 1/4 |
8 x 1 3/8 |
1.31 |
1.50 |
2.00 |
|
10 |
16.00 |
16.00 |
16.00 |
14.25 |
14.25 |
14.25 |
12 x 1 1/4 |
12 x 1 3/8 |
12 x 1 1/2 |
1.44 |
1.62 |
2.19 |
|
12 |
19.00 |
19.00 |
19.00 |
17.00 |
17.00 |
17.00 |
12 x 1 3/8 |
12 x 1 1/2 |
12 x 1 5/8 |
1.56 |
1.75 |
2.38 |
|
14 |
21.00 |
21.00 |
21.00 |
18.75 |
18.75 |
18.75 |
12 x 1 1/2 |
12 x 1 5/8 |
12 x 1 7/8 |
1.69 |
1.88 |
2.50 |
|
16 |
23.50 |
23.50 |
23.50 |
21.25 |
21.25 |
21.25 |
16 x 1 5/8 |
16 x 1 3/4 |
16 x 2 |
1.81 |
2.00 |
2.62 |
|
18 |
25.00 |
25.00 |
25.00 |
22.75 |
22.75 |
22.75 |
16 x 1 3/4 |
16 x 1 7/8 |
16 x 2 1/8 |
1.94 |
2.12 |
2.75 |
|
20 |
27.50 |
27.50 |
27.50 |
25.00 |
25.00 |
25.00 |
20 x 1 7/8 |
20 x 2 |
20 x 2 1/4 |
2.06 |
2.25 |
2.88 |
|
24 |
32.00 |
32.00 |
32.00 |
29.50 |
29.50 |
29.50 |
20 x 2 |
20 x 2 1/4 |
20 x 2 1/2 |
2.31 |
2.50 |
3.12 |
Technical Notes for Procurement
Raised Face (RF): The dimensions above apply to Raised Face flanges. The raised face height is typically 1/16" for Classes 150 and 300, and 1/4" for Classes 400 through 2500. This is included in the minimum thickness calculations.
Tolerance: Our factory maintains machining tolerances within ASME B16.5 limits, typically ±1/32" for outside diameter and bolt circle, ensuring perfect alignment during installation.
Material Certification: While dimensions are standard, 347H flanges must be accompanied by an MTC (Mill Test Certificate) verifying the chemical composition, specifically the Columbium content (10xC min, 1.10% max) to ensure stabilization against sensitization.
Pressure-Temperature Ratings: Do not confuse dimensional class with pressure rating. A Class 150 347H flange can withstand higher pressures at elevated temperatures than a Carbon Steel Class 150 flange. Refer to ASME B16.34 for specific rating values.
As a manufacturer, we understand that these numbers represent more than just measurements; they represent the safety and efficiency of your plant. A flange that is out of specification can cause leaks, downtime, and safety hazards. Our production line is equipped with CNC machining centers and coordinate measuring machines (CMM) to verify every dimension against this chart before shipment.
We invite engineering teams and procurement officers to use this chart as a benchmark for your incoming inspections. If you require custom sizes outside of ASME B16.5 or specific testing protocols for your 347H flanges, our technical team is ready to collaborate.
Contact us today to request a quote on ASME B16.5 347H flanges. We deliver precision, certified quality, and global reliability.
