Piston Seal
COMPACT SEAL
HDP330
The HDP330 piston seal is a two-piece seal set consisting of a VALUE TO THE CUSTOMER
PA sliding ring and an elastomer profile ring as an energizing
element. y Well suited for extreme operating conditions, including working
pressures up to 60 MPa
y Particularly high abrasion resistance ensures long maintenance
PA Sliding Ring intervals, even with lower quality counter surfaces
y Highest resistance to gap extrusion
Profile Ring
y Dynamic and static tightness analogous to PTFE piston seals
y Stepped cut in the seal ring simplifies installation in closed
piston groove
y Rectangular energizing element generates a constantly high
contact pressure and offers high protection against twisting in
Application the installation space
The HDP330 is used in pistons pressurized on both sides.
Preferably suitable for construction machinery and agricultural y Mounting in standardized installation spaces according to DIN
machinery for extreme conditions, such as pressure shocks. Use ISO 7425-1
also in material handling, especially when cold drawn tubes are
provided for low cost cylinders. In addition, HDP330 is used in
hydraulic pumps, especially for small housings and high pressures.
Material
Sliding Ring
Material Designation
Fiberglass filled,
PA 4112
modified Polyamide
Energizing Element
Material Designation
Nitrile Rubber 70 NBR 177605
HNBR as an energizing element on request.
Piston Seal
TECHNICAL PROPERTIES
Operating Conditions Gap Dimension
The maximum permissible extrusion gap with a one-sided posi-
Material PA 4112 / 70 NBR 177605 tion of the piston is significantly determined by the maximum
operating pressure and the temperature-dependent dimension-
Hydraulic Oils, HL, HLP – 30 … +100 °C al stability of the seal material. Please also consult our Technical
Manual.
HFA Fluids +5 … +55 °C
HFB Fluids +5 … +60 °C Maximum Permissible Gap Dimension [mm] @
Inst.
HFC Fluids – 30 … +60 °C Dim. L 16 26 32 40 50 60
[mm] MPa MPa MPa MPa MPa MPa
HFD Fluids –
3,2 0,5 0,5 0,5 0,45 0,35 0,3
Water –
4,2 0,55 0,55 0,55 0,5 0,4 0,35
HETG (rape-seed oil) – 30 … +60 °C
6,3 0,75 0,75 0,75 0,7 0,55 0,5
HEES (synth. ester) – 30 … +80 °C
8,1 1,0 1,0 1,0 0,95 0,75 0,65
HEPG (glycol) –30 … +80 °C
Mineral Greases – 30 … +100 °C These gap dimensions apply to the upper operating temperature of
Tmax = 100 °C, the tolerance recommendations for cylinder, groove and
Pressure 60 MPa guide element. Further information in our technical manual.
Sliding Speed 0,8 m/s
The figures given are maximum values and must not be applied Tolerances
simultaneously.
Nominal Ø D D d
≤250 mm H9 h9
Surface Finish
Roughness Depth Pressure Ra Rmax
Design Notes
≤26 MPa 0,05 … 0,5 µm ≤5,0 µm
Sliding Surface Please note our general design remarks in our Technical Manual.
≤60 MPa 0,05 … 0,3 µm ≤2,5 µm
Groove ≤1,6 µm ≤6,3 µm
Installation & Assembly
Groove Sides ≤3,0 µm ≤15,0 µm A prerequisite for the proper functioning of the seal is careful
installation. Further information in our Technical Manual.
Material content Mr > 50 % to max. 90 %, with cut depth c = Rz/2 and
reference line Cref = 0 %. Rougher surfaces in combination with high stroke
frequency can lead to oil reduction in the sealing gap
Piston Seal
PISTON DESIGN
rounded and burr-free + 0,2
H R2 < 0,2 L rounded and burr-free
20°
C
ØD
R1
Ød
The information contained herein is believed to be reliable, but no representation, guarantees or warranties of any kind are made to its accuracy or
suitability for any purpose. The information presented herein is based on laboratory testing and does not necessarily indicate end product performance.
Full scale testing and end product performance are the responsibility of the user.
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