Barlow's formulasi nima?

Barlow's formula calculates minimum wall thickness for pipes under internal pressure: t = P × D / (2 × S × E), where P = internal pressure, D = outside diameter, S = allowable stress, E = weld joint efficiency factor.

Qanday ruxsat etilgan kuchlanishdan foydalanish kerak?

Ruxsat etilgan kuchlanish material va temperaturaga bog'liq. Tashqi haroratdagi uglerodli po'lat (A106 Gr.B) uchun: ~138 MPa (20 000 psi). Tashqi haroratdagi zanglamaydigan po'lat 316 uchun: ~138 MPa. Loyihalash qiymatlari uchun doimo ASME B31.3 A-1-jadvaliga murojaat qiling.

Payvand birikmasining samaradorlik koeffitsienti nima?

Weld efficiency (E) accounts for joint quality: E = 1.0 for seamless pipe, E = 0.85 for ERW (electric resistance welded), E = 0.60 for furnace butt welded. Higher E requires more inspection (radiography).

Korroziya uchun qo'shimcha o'lcham qo'shish kerakmi?

Ha. Hisoblangan minimal devor qalinligiga korroziya/eroziya zaxirasini qo'shing (jarayon xizmatida uglerod po'lat uchun odatda 1,5–3 mm). Shuningdek, ishlab chiqarish toleransini ham hisobga oling (besizdor quvurlar uchun odatda -12,5%).

Barlow formulasi va ASME B31.3 o'rtasidagi farq nima?

Barlow formulasi soddalashtirilgan variant hisoblanadi. ASME B31.3 t = PD/(2(SE+PY)) formulasidan foydalanadi, bu yerda Y — harorat koeffitsienti. Ko'pchilik holatlarda o'rtacha haroratlarda Y ≈ 0,4. ASME formulasi devor qalinligini biroz kamroq beradi.

Bepul muhandislik vositasi — #154

Quvur devori qalinligi kalkulyatori — Barlow’s Formula

Calculate minimum wall thickness for pipes under internal pressure using Barlow’s formula: t = P×D/(2×S×E). Includes corrosion allowance and tolerance.

t = PD/(2SE)ASME B31.3Korroziyaga chidamlilik zaxirasi

Results

Minimal talab qilinadigan devor qalinligi (korroziya & tolerans hisobida)

—

Hisoblangan t (Barlow)

—

+ Korroziya zaxirasi

—

Burst Pressure (2×S×E×t/D)

—

Ichki diametr

—

Barlow’s Formula

Korroziya va tolerans bilan

P — hisob-kitob bosimi
D — quvurning tashqi diametri
S — hisob-kitob haroratidagi ruxsat etilgan kuchlanish
E — payvand birikmasining samaradorlik koeffitsienti (1.0 — tikuvsiz, 0.85 — ERW, 0.60 — FBW)
c — korroziya/eroziyaga chidamlilik zahirasi
tol — ishlab chiqarish toleransi (odatda 12.5%)

Misol — DN100, 10 MPa bosimda

Given: OD = 114.3 mm, P = 10 MPa, S = 138 MPa, E = 1.0

t = 10 × 114.3 / (2 × 138 × 1.0) = 4.14 mm

+ 1.5 mm korroziya = 5.64 mm

÷ (1 − 0.125) = 6.45 mm minimal

Ushbu xizmat uchun Sch 80 (devor qalinligi 8.56 mm) tanlang.

⚠️ Note: Bu Barlow ning soddalashtirilgan formulasidir. Standartga muvofiqlik uchun Y omilini o'z ichiga olgan ASME B31.3 Eq. 3a dan foydalaning. Hisoblangan minimal qiymatdan yuqori bo'lgan keyingi standart quvur jadvalini tanlang.