RPM Series Metric Piston Seal
With over 30 years of application success, the RPM metric hydraulic piston seal is a proven reliable seal for both low and high pressure systems.
The RPM seal is a double-acting filled TLON® PTFE compound with an o-ring elastomer energizer designed for reciprocating applications. The filled PTFE seal ring is manufactured with an interference fit with the bore and optimum compression with the O-ring energizer. This offers excellent sealability at low pressures and high pressures when the cylinder experiences ballooning. The beveled edges on the RPM ring aid in assembly and crossing over ports in the cylinder. Since the energizers are standard AS568 O-ring sizes, many elastomer compounds are readily available.
Face Grooves:
A standard feature on the RPM seals are conical face grooves on the cap ring. For applications of high pressure rise rates, pressure spikes, and rapid change of direction, the seal is apt to experience blow-by. To prevent blow-by and to energize the seal rapidly, face grooves are added to both sides of the seal. The unique conical groove allows no extrusion path for the o-ring energizer ensuring no loader damage.
Advantages:
- Low seal drag/friction (Minimize energy loss)
- No Stick-slip (Smooth Operation)
- Long seal life from T-LON® filled PTFE compounds
- Available for cylinders up to 500mm diameter
Applications:
- Mobile Hydraulic Cylinders
- Pneumatic Piston Cylinders
- Agriculture Equipment
- Hydraulic Valves and Pumps
- Filling Machines
- Testing Machinery
Technical Data:
(1) T-LON® seal compound determines allowable pressure and velocity ranges
- Velocity: Up to 4 m/s
- Pressure: Up to 60 MPa
(Function of e-gap and T-LON® compound. Max velocity and pressure cannot be used together)
Most Common:
BRONZE FILLED PTFE (“21”)
- Highest Extrusion Resistance (Increased bronze content improves extrusion/wear resistance; i.e. larger e-gap allowable)
- Good sealability
GLASS/MoS2 FILLED PTFE (“31”)
- Good wear resistance for tubes with rougher surface finish (Higher glass content increases extrusion/wear resistance)
- Improved stick-slip resistance
- More chemical resistant but more abrasive on mating components
(2) Loader compound determines temperature and chemical compatibility
Most Common:
NBR SHORE 70 A (“P”)
- Working Temp. Range -1°C to 110°C (121°C intermittent)
- Commonly used with greases, aliphatic hydrocarbon mineral and vegetable oils, and various hydraulic fluids
EPDM SHORE 70 A (“E”)
- Working Temp. Range -45°C to 149°C (204°C steam intermittent)
- Commonly used with water, steam, water/ silicone/ glycol based fluids, and app’s affected by ozone and weathering