Import Alloy Steel Long Welding Neck Flanges — Buy in wholesale FOB from Supplier in China

Alloy Steel Long Welding Neck Flanges from Shijiazhuang Jinmo Pipe Imp & Exp Trading Co., Ltd. are forged components manufactured to ASTM A182 standards with grades F11, F22, and F91 specified in the source data. The extended hub design provides reinforcement for butt-weld connections in high-pressure piping systems, with the long neck geometry distributing stress more evenly than standard weld neck configurations. ANSI B16.5 pressure ratings govern the dimensional and pressure-temperature parameters for these flanges, which are produced in Hebei Province, China for export markets including oil and gas infrastructure projects.

The material specification ASTM A182 covers forged or rolled alloy steel pipe flanges, forged fittings, and valves for high-temperature service. Grade F11 (1.25% chromium, 0.5% molybdenum) suits moderate temperature and pressure applications; F22 (2.25% chromium, 1% molybdenum) offers enhanced creep resistance for elevated temperature service; F91 (9% chromium, 1% molybdenum with vanadium and niobium) provides superior strength and oxidation resistance for the most demanding conditions. Typical manufacturing involves hot forging followed by heat treatment (normalising and tempering or quenching and tempering depending on grade), with 100% visual inspection and dimensional verification to ANSI B16.5 tolerances.

These flanges serve critical junctions in oil and gas pipelines, petrochemical reactor systems, power generation steam lines, and high-pressure water treatment facilities. The long welding neck configuration is preferred for severe cyclic loading conditions and where line expansion and contraction create significant flexural stress. Buyers should confirm the specific grade requirement against their design temperature and pressure conditions, verify Charpy impact test values for low-temperature service, and establish inspection protocols (typically MT or PT for surface defects, RT for critical welds) before placing orders. The supplier lists no response history, so direct technical inquiry through their Shijiazhuang office is advisable to confirm current production capacity and certification status.

Shijiazhuang Jinmo Pipe Imp & Exp Trading Co., Ltd. operates from Xiaomaxincun, Yuhua District, Shijiazhuang 050000, Hebei Province, China. The supplier is classified at imported tier with harbor trust designation, indicating a verified business registration without advanced certification or inspection credentials. Their response rate shows 0.00% with zero average response hours recorded, which suggests either a new listing, dormant account, or data capture issue rather than active engagement metrics.

The company name indicates a trading focus (import and export) rather than manufacturing ownership, which buyers should clarify when requesting mill test certificates or factory audit documentation. No ISO, CE, or API certifications are confirmed in the source data, and any quality claims in the original platform description should be verified directly with the supplier. The listing positions alloy steel flanges for oil and gas, petrochemical, and high-pressure water system applications. Buyers should request material certificates to EN 10204 3.1 or 3.2, confirm traceability to the forging mill, and verify that the stated ASTM grades align with their project material specification before contract.