The pressure profile forms a circumferential boundary layer internally that mitigates the effects of shaft movement because the throttle is designed to float. The standard PSD is designed so the air flow in/out of the seal is biased at 50% as can be seen in the image. Installed correctly the PSD is essentially a non-contact seal which is why it requires no maintenance. In those situations where there is angular misalignment OES PSD-AM design is utilized. In all cases the PSD is engineered to meet our customers specific requirements and performance expectations.
How it works:
The PSD relies on engineered clearances to develop a uniform sealing pressure/velocity profile. This eliminates low pressure area’s mitigating the chance of product ingress into the seal. This can be seen in the pressure profile map from a CFD analysis of the PSD.