Allegheny York
BS Asymmetrical Rod U Cup
https://www.alleghenyyork.com/product...
The BS series hydraulic rod seal is ideally suited for heavy-duty mobile and stationary service where leakage must be held to an absolute minimum. This unique geometry is highly resistant to side loading and insensitive to pressure spikes. The BS profile reduces or eliminates leakage under severe operating conditions. It also reduces wear and dry run. Rod lubricant is retained in the cavity formed by the secondary lip providing exceptionally low running friction even at low velocities. Sealing performance is outstanding ... even at 0 PSI. Temperature: -50°F to 230°F Pressure: 0 to 6000 psi