Main Materials of Hydraulic Cylinder: Cylinder body made of 45# steel, piston rod made of 45# bar material, etc.

Hydraulic Cylinder Seal Brands: U.S. MPI Fluoro-rubber, Swedish SKF PTFE, Austrian Polyurethane

Hydraulic Cylinder Models: 250/160-1200*1880, etc.

Hydraulic Cylinder Types: Hydraulic Foldable Hatch Cover Cylinder, Long Stroke Hydraulic Cylinder

Cylinder Installation Methods: End ring mounting, Mid ring mounting

Hydraulic Cylinder Applications: Hydraulic systems for hatch covers of 10,000-ton container vessels, foldable hatch cover hydraulic systems, hydraulic systems for hatch covers of 10,000-ton bulk carriers. CNMS Machinery is one of the first companies certified by China Classification Society (CCS). The main hydraulic cylinders for ships include: hatch cover hydraulic cylinders, cargo handling hydraulic cylinders, marine steering gear cylinders. Our company has long provided hatch cover cylinders, cargo handling cylinders, etc., to shipyards in Fujian, Zhejiang, and other regions.

Mandatory Inspection and Certification – The Only Certificate Number in the Country

Due to the harsh marine environment, where hydraulic cylinders for ships often operate in humid and highly corrosive conditions, the material quality of the cylinder body and the quality of the seals are especially critical. CNMS Machinery Hydraulic Cylinder Factory, as a company certified by the China Classification Society (CCS), considers product quality to be the lifeblood of the company and has always placed a high emphasis on quality. After years of validation and support by major shipyards in Fujian, Zhejiang, and other regions, the quality of our hatch cover hydraulic cylinders is excellent, with an extremely low failure rate and long service life.

The inner bore of the cylinder is processed through deep hole boring for rough and fine machining, followed by a rolling process. The surface roughness of the cylinder tube can reach 0.4. The rolling process forms a hardened surface layer on the inner bore, which greatly reduces the friction between the piston and the cylinder tube, making it less prone to damage. This effectively enhances the sealing performance of the oil seal and significantly improves the service life of the hydraulic cylinder.

The piston rod undergoes tempering treatment (HB260-280). After rough and fine machining, the surface is polished and then coated with 0.03-0.05mm of hard chrome. It is further polished with specialized polishing equipment to achieve a surface finish of 0.2. This treatment significantly reduces friction, preventing damage to the cylinder tube, and greatly enhances the service life of the hydraulic cylinder.

As a China Classification Society (CCS) certified company, every hatch cover hydraulic cylinder (hatch cover hydraulic cylinder) manufactured by CNMS Machinery Hydraulic Cylinder Factory must undergo strict testing and inspection by affiliated enterprises of the classification society. Only after passing the inspection is the product issued with a certificate number and certification.

Key Advantages

Double Chrome Plating for Strong Acid and Alkali Corrosion Resistance
After B260-280 treatment, an additional layer of 0.01-0.03mm white chrome and 0.03-0.05mm hard chrome is applied, followed by repeated polishing to ensure that the piston rod surface achieves a smoothness of 0.2.

High Fatigue Strength, Safe and Reliable
Based on years of use across various companies, performance tests over 724365 operation have shown that the product is stable, reliable, and guaranteed in quality. It is safe and dependable!

Honing Process Creates a Superior Finish
The cylinder tube’s inner bore undergoes deep hole boring for rough and fine machining, followed by honing. The surface roughness of the cylinder tube reaches 0.4, and the inner bore forms a uniform grid of honing marks, enhancing the quality exponentially!

Alloy Steel Forged Cylinder Tubes
Large forged alloy steels, such as 9Cr2, 9Cr2.0, and 9Cr2W, undergo a series of treatments including forging, preheating, high-temperature processing, thermal insulation, passivation, and high toughness treatment.