York 028 12209 000 O-RING

028-12209-000 is the original factory O-ring (O-RING) for the YORK (a brand under Johnson Controls) water-cooling unit. Its specification is an inner diameter of 0.301 inches (approximately 7.65 millimeters). In the YK centrifugal water-cooling unit shaft sealing parts list (FORM 160.73-RP2), this number is listed as item 83, "O-RING. 0.301" I.D., corresponding to Figure 1. Each unit requires 2 pieces, and it is marked as included in the O-Ring Kit for complete supply. The "028-" section of YOK corresponds to sealing components and pipe connection parts. The same series is classified by inner diameter. Adjacent numbers include 028-12513-000 (5/16" I.D.), 028-12201-000 (1" I.D. sealing O-ring), 028-12200-000 (1-1/8" I.D. sealing O-ring), 028-13832-000 (0.351" I.D.), 028-12961-003 (0.468" I.D. × 0.078"), etc. Different sizes cannot be interchanged.
This O-ring is manufactured according to the original factory size tolerance and elastomer material standards. It is resistant to refrigerating oil, refrigerant corrosion, high and low temperatures, and aging. After being compressed and deformed in the groove, it fills the mating gap, forming a sealing interface in the compressor shaft sealing section and related valve rods, joints, and flange joint surfaces, blocking the leakage of refrigerant and refrigerating oil, and preventing the intrusion of moisture and impurities, maintaining the stability of the system pressure. The O-ring is a wear-prone part. After long-term heat cycling and oil immersion, it will harden, deform, or lose elasticity. It is a frequently replaced part in major maintenance and planned maintenance of the unit. YOK usually recommends replacing the O-ring kit in groups.