What certifications does the company hold?

The company holds ISO9001, API 5CT, and BV Quality supplier evaluation certificates.

What is the lead time for orders?

The average lead time is within 15 workdays for both peak and off-peak seasons.

What payment terms are accepted?

We accept LC, T/T, PayPal, and Western Union.

High-Quality API 5CT K55 5-1/2" Casing Coupling for Oil Industry

Name: High-Quality API 5CT K55 5-1/2" Casing Coupling for Oil Industry
Brand: Tianjin Dongfanglong Petroleum Equipment Manufacture Co., Ltd.
SKU: 1977705341

Tianjin, ChinaTianjin Dongfanglong Petroleum Equipment Manufacture Co., Ltd.

US$12.00

1-99 Pieces

US$11.90

100-999 Pieces

US$9.90

1,000+ Pieces

Sample price:US$30.00/piece.Request sample

Product profile

Warranty

Six Months

Specification

5-1/2"

Trademark

eastlong

Model NO.

5-1/2"

Origin

China

Key features

Wide Grade Range: Available in J55, K55, N80-1, N80-Q, L80, C90, and P110 grades.

Custom Thread Options: Premium thread products available upon customer request.

Extensive Size Coverage: Tubing couplings from 1.9' to 4-1/2'; Casing couplings from 4-1/2' to 20'.

Multiple Thread Types: Includes NU, EU, NUE, EUE, TBG, UPTBG, and upset variants.

Flexible Surface Treatment: Options include whole phosphating or inside phosphating with outside coating.

Customizable Packaging: Available in carton, wooden case, wooden pallet, or customer-specified requirements.

ISO and API Certified: Holds ISO9001, API 5CT, and BV Quality supplier certificates.

Established Manufacturer: Founded in 1999 with 35 senior engineers and 30+ intellectual property rights.

Company profile

Tianjin Dongfanglong Petroleum Equipment Manufacture Co., Ltd.Tianjin, China

Business Type: Manufacturer/FactoryExport Year: 2019-06-07Nearest Port: TIANJIN PORT, QINGDAO PORT, SHANGHAI PORTAverage Response Time: ≤15hTerms of Payment: LC, T/T, PayPal, etc.International Commercial Terms(Incoterms): FOB, EXW, CIF, DDP

AI-Powered supplier vetting

SummaryTianjin Dongfanglong Petroleum Equipment Manufacture Co., Ltd. is a China-based manufacturer founded in 1999, focused on oil pipes, pipe fittings, drilling and production tools, and petroleum automation equipment. The supplier reports ISO 9001 and ISO 14001 certification, 10 production lines, 11–20 years of R&D engineer experience, and 11–20 quality-control staff. It states that its capabilities cover design, development, manufacturing, testing, experimentation, and full-cycle service, supported by more than 30 independent intellectual property rights and an intelligent workshop. The company exports to broad global markets and reports export activity since 2019, but the provided information does not identify specific customer cases or independently verify the stated capabilities.

Supplier typeThe supplier is explicitly identified as a Manufacturer/Factory and a limited company based in Tianjin, China. Its stated business focuses on petroleum equipment, oil pipes, pipe fittings, drilling and production tools, and automation equipment, matching the listed industrial product categories.

CertificationsThe supplier reports holding ISO 14001 and ISO 9001 management-system certifications. These are explicit certification records in the provided data, although certificate scope and validity dates are not given.

R&D capabilityThe supplier reports more than 30 independent intellectual property rights, an intelligent workshop, numerical-control automation equipment capabilities, an e-commerce platform, and recognition as a national science and technology-based small and medium-sized enterprise. These statements provide explicit evidence of innovation-related infrastructure and activity.

Production capacityThe supplier describes an integrated chain covering design, development, manufacturing, testing, and experimentation; operates 10 production lines; and has an intelligent workshop. It also reports oil equipment and pipe-related manufacturing experience, with stated order fulfillment within 15 workdays in both off-peak and peak seasons, supporting a positive production-capability assessment.

Customization capabilityThe stated full-cycle integration of design, development, manufacturing, testing, and experimentation, together with numerical-control automation equipment and an intelligent manufacturing model, indicates the ability to develop and manufacture tailored petroleum equipment. However, no specific customized project examples, engineering-change process, or minimum-order requirements are provided.