1. Main Description
ETERNAL company design and manufacture all kinds of hydraulic cylinders that covering
the following fields:
? hydraulic press cylinder
? construction machinery cylinder
? mining machinery hydraulic cylinder
? metallurgy machinery cylinder
? water power project cylinder
? marine hydraulic cylinder
? servo hydraulic cylinder
Not only we could manufacture all kinds of hydraulic cylinders according to the drawing from our
customers, but also we could make a design according to customer's requirements. If you
require our engineer to make a design, pls advise us the following specification:
1. Rated pressure
2. Working pressure
3. Test pressure
4. Working condition and environment , for example , temperature , working frequency
5. Pulling force , and return stroke force
6. Pulling and return speed
7. Assembly size
8. Seal ring requirements . For example , brand , seal material etc .
9. Tube and piston rod raw material requirements
10. Piston rod surface treatment requirements, for example chromating film thickness .
Surface hardness etc .
11. Painting and other spare parts requirements .
3. Manufacturing capability and cylinder size range
3.1 Cylinder bore diameter : max ?1200mm
3.2 Cylinder length : 10Meter
3.3 Max lifting capability : 50 Tons
4. Manufacturing and inspection
4.1. Cylinder tube size and choice
4.1.1 According to the cylinder pressure and inside diameter size , different steel tube Would be choosed .
1. ID ≤300mm , cold rolled precision seamless tube would be choosed
2. 300mm≤ID ≤500mm , hot rolled seamless tube would be choosed
3. 500mm≤ID ≤1000mm, forged tube would be choosed
4.1.2 Cylinder tube steel grade : SAE1020 , SAE1045 , 27SiMn , S355JR , S355J2G3
St52-3 , SUS304 , SUS316L etc .
4.1.3 Cylinder tube inside boring and honing , roughness R0.2-R0.3.
4.1.4 Cylinder tube inside chromating : if necessary , tube inside chromating could be applied
4.2 Piston rod is a very important part for hydraulic cylinder .
4.2.1 Piston rod steel grade : SAE1045, 42CrMo4, SUS410 , SUS420, SUS304, SUS316L
4.2.2 Piston rod chromating and surface hardness .
Eternal company ensure that every piece piston rod would be surface hardened before chromating .
surface hardness is HRC55~60 , Chromating film thickness is 0.03~0.04mm if there is no other specific
4.3 Seal ring and O ring
According to the customers requirements and working condition , eternal company would choose suitable
seal ring kit , seal ring brand include : Parker , Merkel , NOK , Guangzhou Rubber institute , Taiwan brand etc . Eternal company would supply suitable seal solution for their customer so that hydraulic cylinder has more
lifetime , easy maintenance and simple repairing .
4.4 Tube and flange welding
The welding on cylinder tube and flange would be Ultrasonic tested every time , the welding seam would be
cleaned before machining . Eternal company ensure that every welding seam has no any leak during lifetime
4.5 Assembly and pressure test
Before hydraulic cylinder is assemblied , every spare parts would be measured and cleaned . After hydraulic
cylinder is assemblied , pressure test would be carried out one By one , eternal company ensure that testing
pressure is higher 30%-50% than working pressure , and pressure holding time 30~60 minutes is necessary . Every piece hydraulic cylinder must be tested completely without any leak .
4.6 Painting and storage .
After hydraulic cylinder pass through pressure test , painting is necessary .
The hydraulic cylinder our company produces is available on 6000 t hydraulic press. The maximum pressure of cylinder is up to 1200 t.