After the Montreal Protocol several new classes of refrigerants such as HFCs, PFCs and interim blends of HFCs and HCFCs were developed. Mineral oils and alkylbenzenes were ineffective with the new refrigerants. Synthetic lubricants such as polyol esters (POE) and polyalkylene glycols (PAG) were found to work effectively. The primary difference with these new lubricants is that they are miscible with the new refrigerants.
Miscibility and solubility between the refrigerant and lubricant determine how the two will behave throughout the system. Miscibility is defined as the ability of two liquids to mix together to form a single liquid phase. Solubility is the ability of a gas to dissolve into a liquid.
|
Complete | Freon R-12(CFC) / BVA 3 (MO)134a (HFC) and RPOE LT 32 (POE) |
|
Partial | Freon R-22 (HCFC) / BVA 4 (MO)R-134A (HFC) / RPOE 68 (POE). |
|
Immiscible |
134A (HFC) / BVA 3 (MO) |
There are three types of miscibility. Completely miscible is where the refrigerant and oil mix to form a single phase over the applied temperature range. Partially miscible is a single phase over a limited temperature range. The temperature at which the lubricant and the refrigerant separate into two phases is called the critical solution temperature (CST). Immiscible is when the oil and refrigerant do not mix and stay in two phases.
The BVA RPOE™ Series offers excellent miscibility with HFC refrigerants. It also has excellent chemical and thermal stability, as well as, superior lubricity characteristics on steel and aluminum. To ensure that BVA has the right polyol ester for your application, the BVA RPOE™ Series comes in a wide range of viscosities ranging from ISO 22 (RPOE™22) to an ISO 370 (RPOE™ 370). ™
BVA RPOE™ Series standard group comes witha non intrusive additive package which is suitable for most applications.
BVA RPOE™ EP is a polyol ester with a specially formulated extreme pressure additive for aluminum, bronze and steel. If your application requires an additive free POE then RPOE™ NA would be your choice.
BVA RPOE™ Series is miscible with all HFC, HCFC, CFC and blends. The series was specifically developed for HFC refrigerants. If you decide to use BVA RPOE™ with CFC for an extended period of time, please contact BVA OILS to get the correct viscosity recommendation. BVA RPOE™ Series is available in 16 oz., 32 oz., 1 gallon, 5 gallon and 55 gallon containers. BVA RPOE™ EP and NA are made to order.
