York 028 12200 000 O-RING

028-12200-000 is the original factory-sealed O-ring (SEAL O-RING) for the cooling units of York (a brand under Johnson Controls). It has an inner diameter of 1-1/8 inches (approximately 28.6 millimeters) and is made of black elastomer. In the shaft sealing parts list (FORM 160.73-RP2) of the York YK centrifugal cooling units, this number is listed as item 88, "SEAL O-RING 1-1/8" I.D., corresponding to Figure 7. Each unit requires 2 pieces, and it is marked as included in the O-Ring Kit for complete supply. Adjacent numbers in the same series include 028-12201-000 (1" I.D. sealing O-ring), 028-12209-000 (0.301" I.D.), 028-12513-000 (5/16" I.D.), etc. They are classified by inner diameter, and 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 inserted into the groove, it is compressed and deformed to fill the mating gap, forming a sealing interface in the compressor shaft sealing section and related pipe joints, flange joint surfaces, etc., 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. York usually recommends replacing it in groups with the O-ring kit.