Hydraulic and Pneumatic Seals...since 1975
VNA is a single acting seal that has been conceived to work on the piston and it can be used for simple or double effect. Its has asymmetrical lips which ensure a continuous
contact with the bore, even in case of high misalignments. The installation is done in semi-open groove by overlapping, since the material has a high modulus of elasticity
PRODUCT ADVANTAGES
APPLICATION:
Construction machinery , fork-lift trucks , injection moulding machines , agricultural machinery , loading platforms and standard cylinders
INSTALLATION:
Easy assembly into closed grooves. depending on the minimum diameter values indicated in the table below. Open grooves or special assembly tools should be used for values that are outside this table. If using assembly tool the mounting area should not have any sharp edges. Before mounting the VNA must be lubricated with oil system.
| MINUMUM DIAMETER VALUES FOR CLOSED TYPE OF GROOVES | |||||||
| (D-d)/2 (mm) | 4 | 5 | 6 | 7.7 | 10 | 12.5 | 15 |
| dmin (mm) | 25 | 30 | 40 | 50 | 80 | 100 | 105 |
Note: the permissible sealing gap values of VNA piston seal is given in the below table.
| PERMISSIBLE SEALING GAP Smax(mm) | |||
| t=(D-d)/2 | 150 Bar | 250 Bar | 400 Bar |
| t≤5 | 0.30 | 0.20 | 0.15 |
| t>5 | 0.35 | 0.25 | 0.20 |
Note: The largest sealing gap value occurring on the non-pressurized side of the seal does have a vital importance for the function of the seal and in this respect it is quite important to use the S value lower than the above indicated numbers.
| MATERIAL: PU 92 SH |
| OPERATING CONDITIONS | |||
| MEDIA | Mineral oils(DIN 51524) | HFA and HFB | HFC |
| TEMPERATURE | -30°C +100°C | +5°C +50°C | -30°C +40°C |
| PRESSURE | ≤400 Bar | ≤400 Bar | ≤400 Bar |
| SPEED | ≤0.5 m/sn | ≤0.5 m/sn | ≤0.5 m/sn |
Note: The above data are maximum values and cannot be used at the same time.
| SURFACE ROUGHNESS | Ra | Rmax |
| Sliding Surface ØD-Ød | ≤0.4 μm | ≤3.2 μm |
| Groove Base ØDb-Ødp | ≤1.6 μm | ≤10 μm |
| Groove Flanks B | ≤3.2 μm | ≤16 μm |
Note: It is recommended to have 50% to 90% of the working surface material contact area value.
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CB = Custom build (price on request)
* = Stock item
Stock = 0 (and not a Stock* or CB product) -> minimum item value € 20.00
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