Jiangnan Shipbuilding (2022) — Natural Gas Compression Units (Marine)

Lmart manufactured Natural Gas Compression Units for Jiangnan Shipbuilding. Built to DNV standards, this project demonstrates Lmart’s capability in marine and shipbuilding equipment.

Client	Jiangnan Shipbuilding (2022)
Equipment	Natural Gas Compression Units (Marine)
Design Code	DNV
Scope	LNG container vessel • 8 units • 275 kW each • 711 design

Customer Background

Jiangnan Shipbuilding is a recognized participant in the marine and shipbuilding sector. The company’s operations involve process equipment that must meet stringent safety, quality, and performance standards demanded by the industry and regulatory authorities.

This project required Natural Gas Compression Units engineered to DNV standards, reflecting the technical demands of the application and the client’s commitment to equipment reliability and regulatory compliance.

Challenges and Engineering Requirements

Classification Society Requirements

Marine equipment must satisfy classification society rules (DNV) that go beyond onshore pressure vessel codes. Classification requirements include type-approval of designs, witnessed manufacturing inspections, material grade restrictions for low-temperature service, and impact testing requirements that reflect the operating environment of ocean-going vessels.

Low-Temperature and Cryogenic Service

LNG, LPG, and ethylene carrier equipment operates at temperatures as low as −163°C, requiring materials with verified impact toughness at service temperature. Austenitic stainless steels, nickel alloys, and aluminum alloys are specified based on the specific cryogenic fluid. Thermal contraction during cooldown creates significant stresses at attachment points and pipe connections.

Series Production for Fleet Orders

Ship operators and shipyards often order equipment in series for fleet newbuilding programs. Series production requires consistent quality across all units while optimizing production efficiency. First-article inspection and qualification set the standard; subsequent units follow the qualified procedure with statistical process control to maintain consistency.

Why Jiangnan Shipbuilding Selected Lmart

Classification society approvals. Lmart holds approvals from DNV, Bureau Veritas, CCS, Lloyd’s Register, ABS, NK, and KR — enabling direct supply to shipyards and ship operators worldwide without additional type-approval testing.

Series production capability. Marine equipment orders often involve multiple identical or near-identical units for fleet programs. Lmart’s production system is optimized for series manufacturing, with first-article qualification followed by consistent batch production with statistical quality control.

Cryogenic and specialty material experience. Lmart fabricates equipment in austenitic stainless steels, duplex grades, nickel alloys, and titanium for cryogenic and corrosive marine service. The workshop maintains material segregation and dedicated welding procedures for each alloy system.

Engineering and Manufacturing Solution

Lmart engineered and fabricated Natural Gas Compression Units for Jiangnan Shipbuilding to DNV. The scope of supply included complete detail design, material procurement, fabrication, inspection, testing, and documentation.

Key engineering considerations for this project included thermal-hydraulic performance optimization, material selection for the specific process environment, and compliance with DNV requirements for design, fabrication, and inspection.

The equipment was manufactured at Lmart’s Zhangjiagang facility, which provides full-cycle fabrication capabilities including plate rolling, head forming, machining, welding (SAW, GTAW, SMAW), post-weld heat treatment, and NDE — all under a single quality management system.

Quality Control and Project Execution

Manufacturing was conducted under Lmart’s ISO 9001 quality management system with classification society survey throughout:

• Material verification: All materials supplied with mill certificates reviewed and accepted by the classification surveyor; impact testing per classification rules for low-temperature service where applicable
• Welding and NDE: Qualified welding procedures with welder performance qualifications current for the applicable classification society; radiographic and/or ultrasonic examination per classification requirements
• Pressure and leak testing: Hydrostatic testing witnessed by the classification surveyor; pneumatic or helium leak testing where specified for gas-tight service
• Factory acceptance test: Functional testing of complete assemblies including control system verification, safety device testing, and performance validation
• Documentation: Complete data package including classification certificates, material certificates, weld records, NDE reports, and test reports

Equipment was delivered to Jiangnan Shipbuilding’s designated shipyard, meeting the project schedule requirements.

Results and Business Impact

Lmart successfully delivered Natural Gas Compression Units to Jiangnan Shipbuilding, meeting the project’s quality, schedule, and documentation requirements. The equipment was manufactured to DNV standards, with full documentation packages accepted by the client and applicable inspection authorities.

This project reinforces Lmart’s position as a qualified manufacturer for marine and shipbuilding applications, demonstrating the company’s ability to deliver equipment that meets international quality and certification standards.

Customer Voice

“The equipment was delivered on schedule and the documentation package was complete. The quality of fabrication met our inspection requirements.”

— Jiangnan Shipbuilding project team (paraphrased from project review)

Note: Lmart respects client confidentiality. Specific contact references are available upon request during the qualification process.