Applications:
Temperature: -30°C to 120°C
Exposure to liquids: Refer to the chemical resistance table.
Pressure resistance: See chart in the followings (in the chart: horizontal coordinate: total diameter gap (mm)
Vertical coordinate: Operating pressure (bar); curve labeling (from top to bottom); Limits for NBR back-up rings; limits for PTFE
back-up rings. O-ring hardness will also affect its use.
Advantages of this mounting method
Effective protection of the O-ring thus increasing its service life.
Cost reduction: This system allows the use of seals
that allow larger gaps to reduce machining costs.
The use of back up rings can prevent the seal from extrusion into the radial gap on the low pressure side and maintains the sealing effect. Also, it prevents the O ring from wearing out too quickly.
The diagram shows the O-ring under pressure. It is easy to mount the back up ring. It is installed in the opposite direction of the O ring under pressure to bear the pressure. For double acting piston rods, the back up ring can be mounted on the both side s of the O ring .