Piston seals are sealing rings intended by professional hands to prevent fluid leakage inside the pistons. Products like piston rings are characterized by the gap or split inside the ring. With this gap, it becomes easy to install and dissemble. The gap also makes the seal conform to the surface of cylinder, thus preventing leakage and enhancing sealing efficacy. These piston rings are often applied to hydraulic and pneumatic applications.
Factors That Affect The Piston Seal Design:
There are certain factors that one should consider while designing seals.
Rings can be made with one or multiple materials, depending on the application. However, these products are usually applied in hydraulic and pneumatic applications. Common materials used to prepare piston seals are-
- Thermoplastic Polyurethane (TPU)
- Polytetrafluoroethylene (PTFE)
- Nitrile Rubber (NBR)
- Polyamide (PA)
These materials are intended to bring sturdy, wear and temperature resistant seals for long service in an application.
Displacement gaps- In an application, unexpected spikes in pressure can take place while cylinders react to external forces acting on the piston rods. This can lead cylinder to put more pressure on piston seal. Overloaded pressure is harmful for piston seal and can result in displacement gaps. When you select the right choice of materials, it can help in preventing or at least reducing such troubles.
Guide ring performance – Guide rings are used with piston rings to prevent any metal coming contact with another metal between cylinder bore and piston. The performance of the ring and seal is interlinked. The seal has capability to handle the sliding motion of the piston. While the guide ring has to center the piston to accurately reach the cylinder bore. If this is not achieved in most desirable way, the performance of piston seal can be drastically affected.
Leaks and drifts- When you held your cylinder idle for long time, or it is not in use, the piston is held in inappropriate position by inside fluids. In case excess fluid gets leaked into the cylinder- from internal or external- piston can start drifting.
Static sealing- In few designs, engineers have attached the piston to the rod. It acts like a gasket- maintaining contact with two surfaces without making any risk factor of fluid leakage.
You need to understand these factors before buying piston rings for your applications. Once you understand them all, you won’t fail while collecting the best piston seals.