Lap Joint Flange 20" Class 150 — ASME B16.5
Lap Joint Flange 20" Class 150 to ASME B16.5: outside diameter 700 mm, flange thickness, min 41.3 mm, bolt circle (pcd) 635 mm, number of bolt holes 20, bolt hole diameter 31.8 mm; approx. weight 62.2 kg.
Dimensions of Lap Joint Flange 20" Class 150
| Symbol | Dimension | Value |
|---|---|---|
| O | Outside diameter | 700 mm (27.559 in) |
| tf | Flange thickness, min | 41.3 mm (1.626 in) |
| W | Bolt circle (PCD) | 635 mm (25.000 in) |
| n | Number of bolt holes | 20 |
| h | Bolt hole diameter | 31.8 mm (1.252 in) |
| d | Stud bolt size | 1-1/8" |
| Y | Length through hub | 73 mm (2.874 in) |
| X | Hub diameter | 559 mm (22.008 in) |
| B | Bore | 513.1 mm (20.201 in) |
| m | Approximate weight | 62.2 kg (137.13 lb) |
SKU TSH-FLANGE-LJ-B165-150-20 · Standard ASME B16.5 · weight: Calculated from nominal dimensions, carbon steel (ρ 7850 kg/m³)
Purchase description
FLANGE, LAP JOINT, FLAT FACE, 20" (DN 500), CLASS 150, 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).
Bolting and gasket
20 stud bolts 1-1/8" UNC × 165 mm (6.5") with 40 heavy hex nuts — ASTM A193 B7 studs + A194 2H heavy hex nuts. Gasket: Spiral wound 20" Class 150, ASME B16.20, SS316 + graphite, CS outer ring.
Additional data
| Facing | Flat face (lap) |
Notes
- Lap joint flanges are used with a MSS SP-43 / ASME B16.9 stub end; the raised face is provided by the stub end lap.
Same size, other ratings
Other sizes — Lap Joint, Class 150
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.