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Piston Seals

pistonThe main function of a piston seal is to provide enough resistance in order to maintain the hydraulic pressure necessary to make the piston move. They are internal to the cylinder head and seal against the cylinder bore, preventing fluid from flowing across the piston. Piston seals for hydraulic cylinders separate the two pressure chambers on the rod and piston side of the cylinder. Choosing the appropriate piston seal for a given application is primarily dependent on how the cylinder operates i.e. in single-acting or double-acting operations.

For single acting pistons, high pressure on one side, low on the other, seal behaviour does not differ in principle from that of rod seals. Double acting piston seals have to be symmetrical with reference to a radial plane, and the dynamic leakage is usually less important, as it remains within the actuator. Seals need to be designed in a manner so as there is always a possibility of a thin lubrication film that passing through the contact area between the seal and the cylinder tube surface. A double-acting piston with two single-acting seals is generally avoided as high pressure can be trapped between the seals leading to premature seal failure.

Basic materials: Polyurethane, Nitrile, Fluorocarbon, Silicone, EPDM, fabric reinforced elastomers, PTFE and its compound and other engineering plastics.

Find below ROYAL’s various seal profiles for Hydraulic Piston applications.

 

 

 

 

 

 

Royal Profile Standard Profiles Working Parameters Description
Max. Pressure (bar) Speed (m/s) Temp Range (°C)
PISTON SEALS 
 
PS008N 400 4  -20 to +100   PTFE seal energised with O ring - Double Acting
PS008F 400 4  -20 to +200
 
PS016N 400 4  -20 to +100  PTFE seal energised with O ring - Single acting
PS016F 400 4  -20 to +200
 
PS024 315 0.5  -20 to +100 5 Pc Piston Seal - Complete piston assembly seal - Double Acting
 
PS032 500 1.5  -20 to +100 4 Pc Capped T Seal - Robust seal design for high pressure applications - Double Acting
 
PS040U 400 0.5  -30 to +110 U type Assymetric Seal - For low and medium duty application - Single acting
PS040F 160 0.5  -20 to +200
 
PS048N 400 0.5  -20 to +100 Chevron Vee Packing for Piston application - Robust design for heavy duty single acting application.
PS048F 400 0.5  -15 to +140
 
PS056 315 0.5  -20 to +100 5 Pc Piston Seal - Double Acting applications
 
PS064 400 4  -20 to +100  PTFE seal energised with Square rubber energiser
 
PS072 500 1.5  -20 to +110 Step-cut Polyamide Ring as main seal with Nitrile Oval ring as energiser
 
PS088 500 1.5  -20 to +110 Step-cut Glass filled Polyamide Ring as main seal with Nitrile Square ring as energiser
 
PS096 350 0.5  -20 to +100 Polyurethane ring as main seal with Nitrile Square ring as energiser
 
PS112 400 1  -20 to +100  PTFE seal with X ring at is centre energised with O ring as energiser
 
PS120 400 4  -20 to +100  Glass filled PTFE with MoS2 as main seal energised with Square rubber energiser
 
PS136 400 0.5  -30 to +110 U type Assymetric Seal with AE ring
 
PS152 350 1  -20 to +100 Polyurethane ring as main seal with Nitrile O ring as energiser
  PS160 400 4  -20 to +100  Square PTFE seal energised with O ring as energiser
 
PS168 350 1.5  -20 to +100 3 Pc Piston Seal - T Seal with back up
  PS184 400 1.5  -20 to +110 Step-cut Pure Polyamide Ring as main seal with Nitrile Square ring as energiser

 

 

 

 

 

Piston Seals