Class 300 flange (mm) ¾"" — ASME B16.5
Class 300 flange (mm) ¾"" to ASME B16.5: dn 20, o — outside dia 115 mm, tf — min thickness 14.3 mm, r — raised face dia 42.9 mm, x — hub dia 48 mm.
Dimensions of Class 300 flange (mm) ¾""
| Symbol | Dimension | Value |
|---|---|---|
| · | DN | 20 |
| · | O — Outside dia | 115 mm (4.528 in) |
| · | tf — Min thickness | 14.3 mm (0.563 in) |
| · | R — Raised face dia | 42.9 mm (1.689 in) |
| · | X — Hub dia | 48 mm (1.890 in) |
| · | A — Hub at weld | 26.7 mm (1.051 in) |
| · | Y — Weld neck | 56 mm (2.205 in) |
| · | Y — Slip-on / Thr / SW | 24 mm (0.945 in) |
| · | Y — Lap joint | 25 mm (0.984 in) |
| · | W — Bolt circle | 82.6 mm (3.252 in) |
| · | Holes — No. | 4 |
| · | Hole dia — mm | 19.1 mm (0.752 in) |
| · | Bolt — in | ⅝" in |
SKU TSH-FLANGE-ASME-B16-5-¾" · Standard ASME B16.5 · teshi-web
Purchase description
CLASS 300 FLANGE (MM), ¾"", ASTM A105N, ASME B16.5
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
- Dimensions are in millimetres unless stated otherwise.
- Flange thickness tf and length through hub Y do not include the 2 mm raised face.
- Blind flanges have the same outside diameter, thickness tf and drilling as the other flange types of the same size and class.
- The bore of a weld neck or socket weld flange is machined to match the inside diameter of the pipe schedule stated in the order.
- Bolt holes are tabulated in inches in ASME B16.5; the millimetre values shown are direct conversions (bolt diameter plus ⅛").
- Stud bolt lengths do not include the height of the points. Weights are approximate catalogue values and vary with bore and manufacturer.
Other sizes — Class 300 flange (mm), Standard
½""1""1¼""1½""2""2½""3""3½""4""5""6""8""10""12""14""16""18""20""24""
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.