Opis
Kapica za cevi (tube cap), takođe poznata kao zatvarač, čep, poklopac, navojni čep, itd. Vari se na kraj cevi ili se montira na spoljni navoj kraja cevi da bi zatvorila cev. Koristi se za zatvaranje cevovoda, iste funkcije kao i čep. Glava posude je komponenta posude koja se zavarivanjem spaja sa cilindrom. (pogledajte sliku ispod) Prema geometrijskom obliku, može se podeliti na sferne, eliptične, diske, krunične, konične i ravne poklopce, od kojih se sferne, eliptične, disk i krunične glave zajednički nazivaju konveksne glave.
Primene
Naftni gas, hemijska industrija, elektrane, brodogradnja, farmacija, posude pod pritiskom, gradsko grejanje i vodovodne linije.
Tehničke specifikacije
Standardi: ASME B16.x / EN 102xx / GB/T 12459 / GB/T 14383; Materijali: ASTM A234 WPB; A403 WP304/WP316; A420 WPL6; ugljenični, legirani, nerđajući čelik; Dimenzije: 1/2" - 48" (DN15 - DN1200); Debljina zida / nominalni pritisak: Sch 10 - Sch XXS; Površina: pjeskarenje, uljenje, farbanje ili pocinkovanje.
Referentni standardi
- Naziv standarda
- Standard Specification for Piping Fittings of Wrought Carbon Steel and Alloy Steel for Moderate and High Temperature Service
- Izdavač
- ASTM International
Slični / alternativni materijali
Ovaj proizvod pokriva više osnovnih marki. Alternative ispod su grupisane po porodici — svaka kartica je putanja nadogradnje od označene osnovne marke. Konačan izbor odobrava materijalni inženjer.
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).
Tipične primene po granama
Uobičajena upotreba ovog materijala/kategorije u stvarnim projektima. Uporedite sa projektnom specifikacijom pre zaključenja BOM-a.
- 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).
- Chemical / Food / PharmaAcidic process / process water / CIP loops: A403 WP304L for ambient dilute acid, WP316L with Mo for chloride resistance (matching pipe to A312 is TP304L/TP316L).
- 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).
Standardi i materijali
Sledeće informacije služe za izbor proizvoda i komunikaciju oko RFQ. Konačni zahtevi prate crteže, standarde i nabavnu dokumentaciju.



