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

2. Design

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

requirements .

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.