SPI Series Piston Seal
With over 30 years of application success, the SPI hydraulic piston seal is a proven reliable seal for both low and high pressure systems.
The SPI seal is an inexpensive double- acting filled T-LON® 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.
Since the energizers are standard AS568 o-ring sizes, many elastomer compounds are readily available.
Face Grooves (Optional):
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.
- 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 45″ diameter
- Mobile Hydraulic Cylinders
- Pneumatic Piston Cylinders
- Agriculture Equipment
- Hydraulic Valves and Pumps
- Filling Machines
- Testing Machinery
(1) T-LON® seal compound determines allowable pressure and velocity ranges
- Velocity: Up to 12 ft/s
- Pressure: Up to 8500 psi
(Function of e-gap and T-LON® compound. Max velocity and pressure cannot be used together)
BRONZE FILLED PTFE (“21” or “22”)
- Highest Extrusion Resistance (Higher bronze content increases extrusion/wear resistance; I.E. larger e-gap allowable)
- Good sealability
GLASS FILLED PTFE (“03” or “09”)
- Good wear resistance for tubes with rougher surface finish (Higher glass content increases extrusion/wear resistance)
- More chemical resistant but more abrasive on mating components
(2) Loader compound determines temperature and chemical compatibility
NBR SHORE 70 A (“P”)
- Working Temp. Range -30°F to 230°F (250°F intermittent)
- Commonly used with greases, aliphatic hydrocarbon mineral and vegetable oils, and various hydraulic fluids
EPDM SHORE 70 A (“E”)
- Working Temp. Range -50°F to 300°F (400°F steam intermittent)
- Commonly used with water, steam, water/ silicone/ glycol based fluids, and app’s affected by ozone and weathering.