Import 5-1/2in L80 Ltc Casing Couplings — Buy in wholesale FOB from Supplier in China

The 5-1/2in L80 LTC casing coupling is a threaded connection device used to join two sections of oilfield casing pipe, manufactured to API 5CT standards with L80 grade steel. The L80 designation indicates a yield strength of 80,000 psi, making it suitable for sour service environments where hydrogen sulphide exposure is a concern. The LTC thread profile (Long Thread and Coupling) provides eight threads per inch with a longer thread engagement than STC, offering improved sealing and structural integrity at moderate depths. This specification is commonly deployed in wells where intermediate pressure containment and corrosion resistance are required.

L80 grade material for this coupling category typically contains chromium and molybdenum additions to enhance resistance to sulphide stress cracking, with controlled hardness levels below 23 HRC in accordance with NACE MR0175/ISO 15156. The LTC thread form follows API Buttress thread geometry with a 3-degree load flank and 10-degree stab flank, designed for make-and-break efficiency during running operations. Standard coupling length for 5-1/2in casing in this configuration is typically 225 mm, with outside diameter governed by API dimensional tables to ensure proper clearance in standard boreholes. Surface finish requirements include phosphate coating or copper plating to prevent galling during thread engagement, with thread compound application mandatory for proper seal formation.

Primary buyers include drilling contractors, oilfield service companies, and national oil companies operating in onshore and offshore exploration and production. These couplings are used in well construction phases including surface casing, intermediate casing, and production liner applications where L80 grade specifications are mandated by reservoir conditions. Trade terms for this category typically require confirmation of thread inspection reports, material test certificates, and API monogram licence verification. Buyers should confirm with Dongying Lake Petroleum Technology Co., Ltd whether the supplied couplings include traceable heat numbers, Charpy impact test data, and third-party inspection documentation.

Dongying Lake Petroleum Technology Co., Ltd is located on Huanghe Road in Dongying, Shandong Province, postal code 257000, a region with established oilfield equipment manufacturing infrastructure. The supplier carries an imported tier classification and a harbor trust tier, which indicates a verified business registration with limited transaction history on the platform. The response rate is recorded at 0.00 percent with zero average response hours, suggesting no recent buyer engagement through this channel. Buyers should initiate direct contact to assess current production capacity, quality management system certification status, and reference projects.

The supplier's profile does not disclose factory size, annual revenue, specific API licence numbers, or named client relationships, so these should be verified directly before placing orders. Located in Dongying, the company sits within one of China's concentrated clusters for petroleum machinery manufacturing, which provides access to upstream steel suppliers and downstream machining services. The listing describes API specification compliance and flexible minimum order quantities, though exact figures are not stated and must be confirmed. Prospective buyers should request a factory audit, API Q1 quality system evidence, and sample thread inspection reports prior to commitment.