... 7) However, a reciprocating application will need two hydraulic seals (double acting), one for each of the directions.8) The life of ... working procedures. Application of Seal in Various Industries General mechanical cylinder appropriative seal:USH, UPH, USI, UPI, ODI, IDI, OSI, ... ROI, SPNRI, WR, BRT, RYT, DB, TAY, VB, TC Pneumatic Cylinder appropriative seal:PGY, PNY, GLY, PSD, PDU, PPY, PRY Automotive ...