Deskripsi
Fitting pipa las butt mulus mencakup empat keluarga produk — elbow, tee, reducer dan cap ujung — semuanya diproduksi sesuai ASME B16.9 (NPS 1/2–48 long-radius), ASME B16.28 (short-radius NPS 1/2–24), MSS SP-75 / ASTM A860 (WPHY baja paduan rendah berkekuatan tinggi) dan GB/T 12459. Elbow mengubah arah pipa (45°/90°/180°) pada 1.5D long-radius atau 1.0D short-radius sesuai B16.9. Tee menyalurkan cabang dari jalur utama (sama atau reduksi). Reducer bertransisi antara ukuran lubang (konsentris atau eksentris). Cap menutup ujung pipa (biasanya kepala elipsoidal). Semua fitting dilengkapi ujung bevelled untuk pengelasan butt ke pipa mulus dari bahan yang sesuai; grade akhir, schedule dan kondisi perlakuan panas sesuai gambar / RFQ.
Aplikasi
Digunakan dalam proyek minyak & gas, petrokimia, transmisi gas, pembangkit listrik (termasuk jalur uap utama subkritikal/superkritikal dan reheat), pembuatan kapal, pipa boiler & bejana tekan, pipa makanan dan farmasi; lingkup mengikuti ASME B31.1 / B31.3 / B31.4 / B31.8.
Spesifikasi teknis
Bahan: karbon, baja paduan rendah, paduan, stainless austenitik, dupleks. Elbow dibuat dengan hot-pushing, pressing atau cold extrusion; tee dengan hot-extrusion atau hydraulic bulging; reducer dengan shrinking/expanding; cap dengan pressing atau spinning. Schedule dinding sesuai ASME B36.10M (karbon/paduan, STD/XS/Sch 40/80/120/160/XXS) atau B36.19M (stainless seri S). Dimensi dan toleransi sesuai ASME B16.9 (NPS 1/2–48) dan B16.28 (SR NPS 1/2–24); lubang besar di atas NPS 48 sesuai MSS SP-75 / ASTM A860 WPHY; induction bend buatan pabrik sesuai ASME B16.49. Sesuai ASME B16.9 Bagian 2 (Peringkat Tekanan), fitting las butt tidak membawa peringkat tekanan Kelas — tekanan kerja sama dengan pipa mulus dari bahan, schedule dan OD yang sama. Bahan akhir, schedule, sudut, radius dan kode yang berlaku sesuai gambar atau RFQ.
Standar referensi
- Judul standar
- Standard Specification for Piping Fittings of Wrought Carbon Steel and Alloy Steel for Moderate and High Temperature Service
- Lembaga penerbit
- ASTM International
- Judul standar
- Standard Specification for Wrought Austenitic Stainless Steel Piping Fittings
- Lembaga penerbit
- ASTM International
- Judul standar
- Standard Specification for Piping Fittings of Wrought Carbon Steel and Alloy Steel for Low-Temperature Service
- Lembaga penerbit
- ASTM International
- Judul standar
- Specification for High-Test, Wrought, Butt-Welding Fittings
- Lembaga penerbit
- Manufacturers Standardization Society (MSS)
Material serupa / alternatif
Produk ini mencakup beberapa grade dasar. Alternatif di bawah dikelompokkan per famili — setiap kartu adalah jalur upgrade DARI grade dasar yang berlabel. Pemilihan akhir ditinjau insinyur material.
Switch to A420 WPL6 when service temp ≤ -29°C (Charpy at -46°C); WPB is not qualified for low temperature.
For creep range (~450-540°C) move to 1.25Cr-0.5Mo (WP11) or 1Cr-0.5Mo (WP12).
For high-temp creep / hydrogen service use 2.25Cr-1Mo (WP22), common in hydrotreaters and boiler reheat.
Ultra-supercritical main steam / 540-620°C zones use 9Cr-1Mo-V (Grade 91).
Selection window: MDMT between -101°C and -46°C (colder than WPL6, warmer than 9% Ni). Charpy at -150°F (-101°C); typical for ethylene and deep cryogenic propane lines.
LNG (-162°C) / liquid nitrogen (-196°C) butt-weld fittings use ASTM A420 WPL8 (Ni 8.4–9.6%, commonly called 9% Ni; Charpy at -320°F / -196°C); matching pipe A333 Gr.8, forgings A522.
Chloride service (Cl⁻ > 50 ppm, especially T > 60°C): use 316L; higher chloride or temperature still risks SCC — upgrade to duplex.
Seawater / high chloride / moderate temperature butt-weld fittings: duplex 2205 (A815 WP-S31803), PREN ≈ 35, better pitting resistance than 316L. A182 F51 covers forgings/flanges.
Offshore / FPSO / water injection wellhead: super duplex 2507 (A815 WP-S32750), PREN ≈ 42–43 (industry SDSS threshold ≥ 40). A182 F53 covers forgings/flanges.
Strong acid / high-temp sour / hydrogen service: upgrade to Inconel 625 (UNS N06625, WPNCMC) or Incoloy 825 (UNS N08825, WPNICMC).
Hydrochloric acid / wet chlorine / strongly reducing media: Hastelloy C-276 (UNS N10276, WPHC276).
Aplikasi industri tipikal
Cara umum tim pengadaan menggunakan material/kategori ini. Cocokkan dengan spec proyek sebelum BOM final.
- Oil & Gas PipelinesOnshore crude / gas trunk lines: API 5L X42 and below pair with A234 WPB; X52-X70 must pair with MSS SP-75 WPHY-52/60/65/70 (yield-strength match). Service window -29 to +120°C (B31.4 / B31.8 onshore practice).
- Water & Fire ProtectionMunicipal water, cooling-water loops, fire mains; carbon steel with galvanizing or epoxy lining.
- LNG / CryogenicPropane / LPG (~-46°C) → A420 WPL6; ethylene (~-101°C) → A420 WPL3; LNG (-162°C) / liquid nitrogen (-196°C) butt-weld fittings step up to A420 WPL8 (Ni 8.4–9.6%, commonly called 9% Ni).
- Power GenerationSub / supercritical main steam and reheat lines: WP11 (~540°C) / WP22 (~565°C) / WP91 (~620°C).
- Refinery / HydroprocessingHydrocracking / hydrotreating reactor in/out lines; hydrogen-service per Nelson curve uses WP5 / WP9 / WP22.
- OffshoreSeawater loops / FPSO process lines prefer duplex A815 WP-S31803 (2205) / super duplex A815 WP-S32750 (2507); 316L only for short-term or low-chloride sections (SCC risk above ~60°C even with 316L).
Standar dan material
Informasi berikut digunakan untuk pemilihan produk dan komunikasi RFQ. Persyaratan akhir mengikuti gambar, standar, dan dokumen pembelian.



