Backup Rings, O-Ring Material, Metric O-Ring O-Rings l General Information l Backup rings for O-Rings l O-Ring Cords l Encapsulated O-Rings l O-Ring Kits l Amedican Standard (AS-568 Series)      Swedish / Japanese Std. (P & G Series)  Tolerances Part List O-Ring Recessing Arrangement   Tolerances Part List O-Ring Recessing Arrangement   Backup Rings for O-Rings : - The higher the pressure used in a system, the greater the demand made on the O-Ring When an O-Ring is subjected to a pressure, the rubber tends to flow into the clearance between the adjacent machine parts. At low pressure, this tendency is a slight one, but at around 10Mpa (100Bar) the extrusion can become excessive. Therefore at pressure exceeding 10Mpa (100Bar), it is necessary to take special measures. This is because extrusion can lead to permanent damage to the O-Ring thus resulting in imperfect sealing. We can resolve this by reducing the clearance between the metal surface to a minimum and to use close tolerances, but this is an expensive way. Alternatively, we can use higher hardness rubber material like 90 Shore A Duro, but that makes the seal less elastic and flexible. Therefore the most suitable solution is to use Backup Rings. Backup Ring material are NBR 90 Shore A Duro, Polyurethane 90 Shore A Duro, YBPO, PTFE etc. Note: Backup Rings intended for AS-568 O-Ring and Swedish / Japanese Standard O-Rings are not listed. More information on them available on request. For Metric and Special O-Ring sizes, please contact us. Top About Us | Seal Products | Design Help | Seal Guru | Seal Failure Causes | Glossary | Seal Express | O-Ring Quote | Contact Us | O-Ring Basics | Elastomer Properties | Elastomer Storage | Chemical Compatibility | Profile Chart | Oil Seal | O-Rings | Pneumatic & Hydraulic Seals | Shaft Seal | Engineering Plastic | Protector & Cap | V-Packing | Packer Elements | PTFE Seal | PTFE Joint Seal | Bonded Seal | Valve Seats | PPS Seals | HNBR Seal | NBR Seal | EPDM Sea| FKM Seal | PEEK Seal | Gas Lifts | API Seal Rings | Casing O-Rings | Gas Lift Valve Seals | PU Seals | MQ Seals | Seals for Premium Connections | Link Us |