What does the hero weight include?

W_pair = 2 × W_f + W_g + full stud/nut set. It is the mated joint screening mass for rigging — not a single flange catalog weight.

How is WN hub bore chosen?

Weld-neck bore uses the selected pipe schedule ID from the pipe-schedule table (B36.10M), defaulting to Sch 40 / STD. Slip-on / socket-weld use pipe OD. Blind is solid.

How are Blind / SO / SW masses calculated?

WN uses the stored B16.5 WN RF catalog mass. Blind uses a solid-disc screening estimate (7850 kg/m³ × π/4 × OD² × T) — not 0.85×WN — because high-class / large blinds are often heavier than WN. SO / SW apply type factors 0.70 / 0.75 unless a type-specific override is stored. Always confirm vendor weights for purchasing and rigging.

When is ASME B16.47 required?

B16.5 covers NPS ½–24. NPS 26–60 use B16.47 Series A or B (non-interchangeable). Those sizes are not in this calculator.

Flange Dimension & Weight for 3 Inch Class 300 | FieldEngineersKit

Parameter	Value
Nominal pipe size (NPS)	3"
Pressure class	Class 300

1. Core Formula & Variable Definitions

ASME B16.5 (Pipe Flanges and Flanged Fittings NPS ½–24) · ASME B16.47 (Large Diameter Steel Flanges NPS 26–60) — reference only; not tabulated here · ASME B16.20 (Metallic Gaskets for Pipe Flanges) · ASME B36.10M (Welded and Seamless Wrought Steel Pipe) — WN hub bore

W_pair = 2 · W_f + W_g + n · (W_stud + 2 · W_nut)

Lookup: OD, T, PCD, bolt holes · WN hub bore = selected pipe schedule ID (B36.10M) · Blind W_f = solid-disc screening estimate

ASME B16.5 flange envelope & mated-pair screening mass (this app)

Scope B16.5 NPS ½–24W_pair 2 W_f + W_g + hardwareWN bore Selected schedule IDBlind W_f Solid-disc estimate

This calculator looks up ASME B16.5 dimensions and screening masses for NPS ½–24 (Classes 150–1500; Class 2500 through NPS 12). Select flange type (WN / SO / SW / BL), facing (RF / FF / RTJ≥300), and pipe schedule for WN hub bore. Blind W_f uses a solid-disc estimate (ρ·π/4·OD²·T); SO/SW scale the WN RF catalog mass by type factors unless a type override is stored. Facing adjusts gasket mass and stud length. Hero W_pair = 2 flanges + gasket + full stud/nut set. Stud lengths are screening — confirm B16.5 / vendor lists before PO. Large diameters NPS 26–60 are B16.47 (not in this table).

OD (Flange Outside Diameter) — Circular flange forging OD from the B16.5 row (mm or in).
T (Flange Thickness) — Minimum flange ring thickness from the table (mm or in).
PCD (Bolt Circle / Pitch Circle Diameter) — Circle through bolt-hole centers (mm or in).
n (Bolt Hole Count) — Number of studs / bolt holes on the flange.
W_f (Single Flange Mass) — WN: B16.5 catalog screening mass. Blind: solid-disc estimate (ρ·π/4·OD²·T). SO/SW: WN mass × type factor (0.70 / 0.75) unless a type override exists (kg or lb).
W_g (Gasket Mass (screening)) — Spiral-wound RF / FF / RTJ screening mass with facing factor.
W_pair (Mated Pair Assembly Mass) — Hero output: 2×W_f + W_g + n×(W_stud + 2×W_nut).

2. Allowances, Tolerances & Standards

Dimensions and masses are screening lookups. Confirm vendor drawings for facing height, RTJ ring, and stud length before procurement.

Raised Face Height (B16.5)1/16" Cl 150/300 · 1/4" Cl ≥ 600

Cl 150/300 RF height is typically included in catalog T. Cl ≥ 600 adds 6.4 mm RF beyond minimum T. This calculator stores T from the app table — verify facing on the mill drawing.

Hub Bore MappingWN → selected schedule ID · SO/SW → pipe OD · BL → solid

WN hub bore follows the pipe schedule selected in Input Parameters (default Sch 40 / STD). Slip-on / socket-weld use pipe OD. Blind has no bore. SW above NPS 2 is flagged as screening-only in the UI.

Stud Length ScreeningRF / FF / RTJ deltas by class

Base stud length from the table is adjusted for facing and rounded to 5 mm. Confirm ASME B16.5 Appendix / vendor stud charts for purchase.

B16.47 Series A vs BNot interchangeable · out of scope

NPS 26–60 use B16.47 Series A or B bolt patterns that do not mate. This lookup stops at NPS 24.

Quick Reference Lookup Table

ASME B16.5 WN RF Class 150 — matches flangeDimension.json (this app)
NPS	Flange OD (mm)	Thickness T (mm)	Bolt circle (mm)	Bolts
2"	152.4	19.1	120.7	4 × 5/8"
4"	228.6	23.8	190.5	8 × 5/8"
6"	280	23.9	241.3	8 × 3/4"
8"	342.9	28.4	298.5	8 × 3/4"
10"	405	28.6	362	12 × 7/8"
12"	485	30.2	431.8	12 × 7/8"

Values match data/piping/flangeDimension.json Class 150 WN RF rows. Live lookup also covers Classes 300–1500 (2500 through NPS 12) and type/facing factors. Unit toggle converts OD / T / PCD columns.

3. Material & Code Limitations

Pressure Class is not a constant psi/bar rating. MAWP follows ASME B16.5 Table 2 by material group and temperature — outside the dimension engine.

Material Group	Temperature Range	Allowable Stress / Limit	Engineering Notes
Group 1.1: Carbon Steel (ASTM A105 / A350 LF2)	-29 °C to 425 °C (-20 °F to 800 °F)	Cl 150 ≈ 19.6 bar @ 38 °C → ~6.5 bar @ 300 °C (A105)	Most common forged flange material. Confirm Table 2 for the actual group.
Group 2.1 / 2.2: Stainless (A182 F304/L, F316/L)	-196 °C to 538 °C (-320 °F to 1000 °F)	Often lower ambient MAWP than A105 for the same class	Use stainless ratings when the isometric specifies SS flanges.
Facing Compatibility (RF / FF / RTJ)	Per gasket / ring OEM	RTJ enabled in-app for Class ≥ 300	Do not mate cast-iron FF to steel RF without full-face gasket / face machining — bending can crack CI.
Type Mass Basis (this app)	N/A	WN catalog · BL solid-disc · SO 0.70 · SW 0.75	Blind no longer uses 0.85×WN. Optional weightKgBl/So/Sw overrides in the data table take precedence when present. Confirm vendor weights for PO.

Code Applicability & Safety Boundaries

Calculator scope: B16.5 OD/T/PCD/bolting lookup, WN schedule bore, Blind solid-disc / SO·SW type-factor mass screening, and W_pair. It does not compute MAWP or B16.47 large flanges.
Always use W_pair (not W_f alone) for spool rigging and rack deadload estimates.
RTJ ring numbers are B16.20 screening IDs — confirm the gasket OEM chart.

4. Step-by-Step Worked Example

Field VerificationShow

Reproduce the app path for NPS 6 Class 300 weld-neck RF: read OD, T, PCD, bolting, W_f, and W_pair from flangeDimension.json (same source as the live calculator).

Nominal Size:NPS 6 (DN 150)Pressure Class:Class 300Type & Facing:Weld Neck RF (default)Hub Bore Basis:Selected pipe schedule ID (default Sch 40 / STD)Mass Basis:WN catalog / Blind solid-disc / SO·SW type factor

1

Read B16.5 envelope from the app table

NPS 6 Class 300: OD = 320 mm, T = 35 mm, PCD = 269.9 mm, raised-face sealing OD = 215.9 mm.

Result:OD = 320 mm, T = 35 mm, PCD = 269.9 mm

These values match data/piping/flangeDimension.json (not older handbook rounded SEO).

2

Read bolting layout

n = 12 holes, stud diameter = 3/4", screening stud length = 120 mm (RF), wrench AF = 1-1/4" (32 mm).

Result:12 × 3/4" studs · L = 120 mm

Shown in Field bolt & tool specs and the live joint preview.

3

Single flange mass W_f

W_{f} = W_{t ab l e} \cdot f_{t y p e}

WN factor = 1.00. W_f = 19.1 kg (table).

Result:W_f = 19.1 kg

SO would use 0.7 × 19.1 ≈ 13.4 kg. Blind uses a solid-disc estimate instead of 0.85×WN.

4

Hardware + gasket

W_{h w} = n (W_{s t u d} + 2 W_{n u t}), W_{g} = 0.29 kg

Table W_stud = 0.268 kg → app rounds to 0.27 kg; W_nut = 0.118 kg → per set 0.506 kg. W_hw = 12 × 0.506 = 6.07 kg. W_g = 0.29 kg.

Result:W_hw = 6.07 kg, W_g = 0.29 kg

Screening masses from the same JSON row; stud mass is rounded to 0.01 kg in the engine.

5

Mated pair W_pair (hero)

W_{p ai r} = 2 W_{f} + W_{g} + W_{h w}

W_pair = 2 × 19.1 + 0.29 + 6.07 = 44.56 kg.

Result:W_pair = 44.56 kg

Matches the calculator hero for NPS 6 Class 300 WN RF.

Conclusion: NPS 6 Class 300 WN RF in this app: OD 320 mm, T 35 mm, PCD 269.9 mm, 12 × 3/4" × 120 mm studs, W_f = 19.1 kg, W_pair = 44.56 kg. Use W_pair for rigging — not the single-flange catalog mass alone.

5. Frequently Asked Questions & Technical References

Show

No. Class is a dimensionless designator. MAWP comes from ASME B16.5 Table 2 by material group and temperature (e.g. A105 Class 150 ≈ 19.6 bar at 38 °C, much lower at 300 °C).

Flange Dimension & Weight — 3 Inch Class 300

3 Inch Class 300 specification summary

1. Core Formula & Variable Definitions

2. Allowances, Tolerances & Standards

Quick Reference Lookup Table

3. Material & Code Limitations

Code Applicability & Safety Boundaries

4. Step-by-Step Worked Example

Read B16.5 envelope from the app table

Read bolting layout

Single flange mass W_f

Hardware + gasket

Mated pair W_pair (hero)

5. Frequently Asked Questions & Technical References

Flange Dimension & Weight — 3 Inch Class 300

3 Inch Class 300 specification summary

1. Core Formula & Variable Definitions

2. Allowances, Tolerances & Standards

Quick Reference Lookup Table

3. Material & Code Limitations

Code Applicability & Safety Boundaries

4. Step-by-Step Worked Example

Read B16.5 envelope from the app table

Read bolting layout

Single flange mass W_f

Hardware + gasket

Mated pair W_pair (hero)

5. Frequently Asked Questions & Technical References

Does Class 150 mean the flange is rated for 150 psi?

What does the hero weight include?

How is WN hub bore chosen?

How are Blind / SO / SW masses calculated?

When is ASME B16.47 required?