DESIGN

Di Natale - Bertelli spa has a well-equipped and efficient technical office, where a design team studies and implements the proposed solutions.

Thanks to sophisticated software (CAD on 2 workstations), the realization of the finished product is scrupulously analysed, reflecting and managing all the possible variables, which take place during use.

For the components, we calculate precisely the effort and wear to which they will be subjected during use. These calculations are then applied to the entire structure of the telescopic cylinder in order to have a clear understanding of the points of greatest load and effort.

All this is a philosophy, which Di Natale – Bertelli spa applies indiscriminately to everything he does.

Telescopic cylinder engineering

TECHNICAL SPECIFICATIONS

MATERIAL

The telescopic cylinders are made with seamless rolled tube big thickness: ST. 52.0 DIN –1629 R=500-650 N/mm² Rs=355 N/mm² MW 450 20 MnV 6 R=550-720 N/mm² Rs=420 N/mm² base and ball socket joints in pressed steel: Fe 510 R=450-630 N/mm².

STAGES

The saline nitriding treatment, correctly know as the "TENIFER TF1 Degussa process", used by Di Natale - Bertelli S.p.A means that the stages can be free from bushings or guide rings as they have sliding surfaces which are highly resistant to wear and seizing, principally as a result of high surface hardness of HV-5/12=430-650.
The prime advantage of these stages is that due to the characteristics described above, they are free from the related ring and bushing seats, giving them mechanical strength at the extremities which far exceeds the standard available on the market and leaving them free from problems with burring.
This also allows a longer guide and enables the cylinder to be operated at maximum pressure at the end of its stroke.

TESTING

All the cylinders have a final functional test.

Cylinders with a maximum working pressure of 220 bar are subjected to a final testing at hydraulic pression of 240 bar. (245 kg/cm2)

Cylinders with a maximum working pressure of 200 bar are subjected to a final testing at hydraulic pression of 220 bar. (225 Kg/cm2)

This phase guarantees total control in the commercialization of our products.

SURFACES

The outer surfaces of the stages are subjected to an initial grinding phase followed by lapping, giving them a degree of roughness between 0.07 and 0.25 µm, checked at each cycle with a roughness tester.

SEALS

The specially shaped seals and scrapers are project by Di Natale - Bertelli S.p.A.:

Material : polyurethane: (Du Pont)
Maximum pressure 400 Kg/cm² (395 Bar)
Temperature from -40 to +110 C.
Maximum piston speed 0.5 m/s
Oil : Hydraulic oils and lubrificants mineral based.

You have to require seals in Viton material with glycol-water or similar substances

REGULATIONS

All the products are projected by international regulations CNR-UNI 10011 considerated a safety factor Ks = 1,5.