Plate & blind flange NB 250 Table H — BS 10
Plate & blind flange NB 250 Table H to BS 10: outside dia 431.8 mm, bore / id (plate) 275 mm, thickness — plate rf 34.9 mm, thickness — blind rf 34.9 mm, pcd (web ref.) 381 mm.
Dimensions of Plate & blind flange NB 250 Table H
| Symbol | Dimension | Value |
|---|---|---|
| OD | Outside dia | 431.8 mm (17.000 in) |
| · | Bore / ID (plate) | 275 mm (10.827 in) |
| · | Thickness — plate RF | 34.9 mm (1.374 in) |
| · | Thickness — blind RF | 34.9 mm (1.374 in) |
| · | PCD (web ref.) | 381 mm (15.000 in) |
| · | No. of bolts (web ref.) | 12 |
| · | Bolt size (web ref.) | 22.2 mm (0.874 in) |
| · | Teshi QC flag | STD~ID |
SKU TSH-FLANGE-BS-10-TABLE-H-250 · Standard BS 10 · Teshi master data
Purchase description
PLATE & BLIND FLANGE, NB 250, TABLE H, ASTM A105N, BS 10
Available materials: ASTM A105N, ASTM A350 LF2 Cl 1, ASTM A182 F304/304L, ASTM A182 F316/316L, ASTM A182 F11 Cl 2, ASTM A182 F22 Cl 3, ASTM A182 F51 (Duplex), ASTM A182 F53 (Super Duplex), ASTM A694 F52 / F60, IS 2062 E250 (plate).
Notes
- PLATE FF thickness identical to PLATE thickness for every size; FF column omitted.
- BLIND FF thickness identical to BLIND thickness for every size; FF column omitted.
Same size, other ratings
Other sizes — Plate & blind flange, Table H
NB 15NB 20NB 25NB 32NB 40NB 50NB 65NB 80NB 90NB 100NB 125NB 150NB 175NB 200NB 225NB 300NB 350NB 400NB 450NB 500NB 600
Frequently asked questions
What are the main types of pipe flanges?
Weld neck (WN), slip-on (SO), blind (BL), socket weld (SW), threaded (THD), lap joint (LJ) and plate flanges. Special types include orifice, long weld neck, reducing flanges and spectacle blinds.
When should I use a weld neck flange instead of a slip-on?
Use weld neck flanges for high pressure, high or cycling temperature, and lines with vibration or fatigue loading. The tapered hub and full-penetration butt weld spread stress smoothly. Slip-on flanges are cheaper and easier to align, but their fatigue life is roughly one third of a WN.
What does Class 150, 300 or 600 mean on a flange?
The ASME class is a pressure-rating designation, not a pressure in psi. The allowable pressure depends on the material group and temperature. A Class 150 A105 flange is rated 19.6 bar at 38 °C but 13.8 bar at 200 °C.
Is a 150# flange rated for 150 psi?
No. A Class 150 carbon-steel flange is rated about 285 psi (19.6 bar) at ambient temperature, and about 170 psi (11.7 bar) at 260 °C. The "150" is a class number.