Refrigeration compressor oils must lubricate moving parts effectively while satisfying requirements not demanded from other general purpose lubricating oils. Unlike such oils, refrigeration oils are expected to give trouble-free service. Lubrication, of course, is considered the primary function of a compressor oil. In addition, it must have certain other properties because:

• It mixes intimately with the refrigerant used in the system.
• It is carried over in small amounts into the refrigeration lines.
• It is in direct contact with the motor windings in hermetic units.
• It is exposed to temperature extremes: high temperatures at the compressor discharge valve, and very low temperatures at the expansion valve.

Suniso refrigeration oils have the following characteristics which assure maximum trouble-free service life:

• CHEMICAL STABILITY : To resist interaction with the refrigerant or metal parts in the system.
• THERMAL STABILITY : To eliminate excessive carbon deposits at compressor hotspots such as valves or discharge ports.
• LOW WAX CONTENT : To prevent separation of flocculent wax from the oil-refrigeration mixture at the low temperature points in the system.
• LOW POUR POINT : To prevent separated oil from congealing in refrigerant lines.
• HIGH DIELECTRIC STRENGTH : To ensure good insulating properties. In hermetic units, the oil-refrigerant mixture serves as an insulator between the motor and the compressor body.
• PROPER VISCOSITY : To ensure high film strength at elevated operating temperatures and good fluidity under the coldest operating temperatures even when diluted with refrigerant.
• NO CONTAMINATION : To prevent scarring of bearing surfaces, plugging of lines or oil ports and general deterioration.

Suniso GS was introduced by Sun Oil Company back in 1968. The new Suniso reference was an important upgrade to the industry’s requirement making Suniso GS superior to all other existing references on the market. Suniso GS had become the new Grade Standard, in short GS.

The Suniso brand was created in 1933 and produced in the famous refinery of Marcus Hook in Philadelphia, USA. In 1984, the Suniso brand was bought by Witco (Crompton). Sun Oil Company Belgium NV acquired the exclusive manufacturing & distribution rights in that same year.

Today the brand ownership is in the hands of Sonneborn Inc. In 2008, the family business of Sun Oil in Belgium was purchased by Petronas Lubricants International (wholly owned subsidiary of Petronas) that transformed the company into Petronas Lubricants Belgium NV. Under the management of PLI, the activities were anchored in the renewed Hemiksem plant in Belgium while embracing the strong Petronas focus on safety and quality.