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Flanges · Weld Neck

Weld Neck Flange RF 6" Class 2500 — ASME B16.5

Weld Neck Flange RF 6" Class 2500 to ASME B16.5: outside diameter 485 mm, flange thickness, min 108 mm, raised face diameter 215.9 mm, raised face height 6.4 mm, bolt circle (pcd) 368.3 mm; approx. weight 138.2 kg.

BXRWOtfYSECTIONn × hFACE VIEW
Weld Neck Flange RF 6" Class 2500 — dimension symbols match the table below. © Teshi Group · www.teshigroup.com

Dimensions of Weld Neck Flange RF 6" Class 2500

SymbolDimensionValue
OOutside diameter485 mm (19.094 in)
tfFlange thickness, min108 mm (4.252 in)
RRaised face diameter215.9 mm (8.500 in)
fRaised face height6.4 mm (0.252 in)
WBolt circle (PCD)368.3 mm (14.500 in)
nNumber of bolt holes8
hBolt hole diameter54 mm (2.126 in)
dStud bolt size2"
YLength through hub273 mm (10.748 in)
AHub diameter at weld (pipe OD)168.3 mm (6.626 in)
BBore (Sch 40)154.1 mm (6.067 in)
mApproximate weight138.2 kg (304.68 lb)

SKU TSH-FLANGE-WN-B165-2500-6 · Standard ASME B16.5 · weight: Calculated from nominal dimensions, carbon steel (ρ 7850 kg/m³)

Purchase description

FLANGE, WELD NECK, RAISED FACE, 6" (DN 150), CLASS 2500, BORE SCH 40, 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

8 stud bolts 2" UNC × 370 mm (14.75") with 16 heavy hex nuts — ASTM A193 B7 studs + A194 2H heavy hex nuts. Gasket: Spiral wound 6" Class 2500, ASME B16.20, SS316 + graphite, CS outer ring, SS inner ring.

Additional data

FacingRaised face 6.4 mm, 3.2–6.3 µm Ra serrated

Same size, other ratings

Other sizes — Weld Neck, Class 2500

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.

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