Piston U-Ring P29

Single-acting Piston U-Ring P29 with asymmetrical profile and shortened outer lip. Recommended up to 10 Mpa working pressure. An back-up ring will extended working pressure up to 16 Mpa.

Piston U-Ring P29 can be installed in “back-to-back” position in double-acting piston design with pressure on both sides. It has Very good static and dynamic tightness and is good choice for specific requirements.

Light hydraulic cylinders.
Pneumatic cilinders
Earth moving equipment
Industrial vehicles
Agriculture equipment

Standrad material
Material base NBR 85 NBR 85 NBR 80 FPM 85

For applications that may require alternative materials or for verification current availability of tools and part numbers, contact us.

Pressure, Speed
Working pressure, P 10 MPa
Running speed, v 0,5 m/s
Medium, Working Temperature
Material code N4280 N5185 N7272 F9193
Hydraulic oils HL, HLP -30 to 100˚C -50 to 90˚C -60 to 80˚C -15 to +200˚C
HFA, HFB fluids +5 to +60˚C +5 to +60˚C +5 to +60˚C
HFC fluids -30 to +60˚C -30 to +60˚C -30 to +60˚C
HFD fluids -15 to +200˚C
Water +5 to +90˚C +5 to +90˚C +5 to +80˚C
Mineral greases -30 to +100˚C -50 to +90˚C -60 to +80˚C -15 to +200˚C
Max. permissible gap dimension, emax
Max operating pressure S ≤ 7,5mm S > 7,5mm
5 Mpa 0,30 0,35
10 Mpa 0,20 0,25


Surface quality*
Surface roughness Ra Rmax
Sliding surfaces 0.05.. 0,3 μm ≤ 2,5 μm
Groove base ≤ 1,6 μm ≤ 6,3 μm
Groove flanks ≤ 3,0 μm ≤ 15 μm

*Contact area Mr = 50% to 90% at cutting depth c=Rz/2 and reference line Cref=0%