Tianjin Zhongjian Hai an Engineering Co., Ltd. is a Tianjin-based marine technical services company supporting merchant shipping at Tianjin Xingang and the surrounding Bohai Bay terminals with a broad statutory and periodical service portfolio. The Zhongjian Hai An team handles annual and five-yearly servicing of lifeboats and rescue boats, inflatable liferaft inflation and pack-up, davit and launching system inspections, inflatable lifejacket and immersion suit checks and lifting appliance and gear surveys including proof load testing of cargo cranes and provision derricks. Fire-fighting equipment work includes portable extinguisher recharging and pressure testing, fixed CO2, foam and water-spray system inspections in machinery spaces, hydrostatic testing of fire hoses and hydrants, and EEBD and SCBA breathing apparatus maintenance with cylinder hydrostatic tests at five-yearly intervals. Structural services cover hatch cover ultrasonic tightness testing under IACS UR Z17, watertight integrity verification under SOLAS II-1, pressure vessel inspection on portable extinguishers and SCBA cylinders, and NDT examinations on welds and components using magnetic particle, dye penetrant and ultrasonic methods. In-water hull inspections in lieu of drydocking are coordinated through partner diving teams, with reports formatted for class acceptance. Spare-parts supply and stock control include hydrostatic release units, pyrotechnics, lifejackets and inflation-system spares with traceable batch records. The company is recognised as a service supplier by ABS, DNV, Bureau Veritas, the China Classification Society and Lloyd's Register, allowing its servicing certificates and inspection reports to be accepted by attending class surveyors and Chinese flag-state authorities for merchant tonnage operating at the major ports of northern China.