HPS MA44 - U-rings

Type/Ref.: Piston seal
Pressure (bar): 35/350
Temperature (°C): -150 to +250
Running speed (m/s): up to 15

HPS MA44 piston seal with a V-spring as an energising element

Standard material

PTFE/carbon compound non-corrosive, acid-resistant steel 1.4310

Area of application

All areas of general mechanical
and apparatus engineering,
chemical engineering and process
hydraulics and pneumatics,
reciprocating movements


The HPS MA44 is a single function piston seal in the form of a U-ring with seal lips of varying design. These achieve optimal sealing strength and reduce friction. This results in the seal having an exceptionally long service life. The metal spring permanently activates the seal lips which guarantees zero leakage even in an unpressurized state. As a result of the exceptionally positive material characteristics of PTFE, there is no stick slip movement of the piston at differing stroke speeds, even during a single cycle and with extremely slight movements. Total lack of leakage with regard to media viscosity and its hydrodynamic dragging behaviour as well as dependable functioning in high temperature, speed and pressure areas characterise these seals. They are used as piston seals in hydraulics and pneumatics.


All types of hydraulic oils, hot air, steam and most chemicals

Operational application limits

Pressure (MPa/bar): 35/350
Temperature (°C): -150 to +250
Running speed (m/s): up to 15


We generally recommend split seal housing. In a limited range, half-open or closed housing is also possible. Please also follow the general installation instructions.


For operating conditions other than the standard applications, further PTFE compounds and V springs made of ELGILOY® are available. The use of PTFE compounds in the pharmaceutical and foodstuffs industries is completely harmless. However, in this case, the spring housing of the seal should be filled completely with a flexible silicone casting compound so that a smooth surface is formed. Please mention this application when placing your orders.