Pressure and check valves
In order to return oil from the reservoir back to the com pres sors at a sufficient flowrate, there must be a differential bet ween reservoir pressure and crankcase pressure. A valve type RV2.. is installed between the oil reservoir and the suction line on single stage plant.
On two stage machines, where the crankcase is at an intermediate pressure and Booster systems, it is advisable to connect the equalizing line to this intermediate pressure.


Operation with R717 (ammonia) und R290 (propane) 
The valves type RV.. are approved for R 290, R 600a and R 717. For the refrigerants R 723 and R 1270 we provide valves on request.

Technical specification
Max. allowable operating pressure (PSmax) As per table
Max. allowable operating temperature : 100°C


The two-way-valve RV2-10B-1,5-2W
In CO2 units due to the special properties of the refrigerant conditions with significant pressure fluctuations can occur. As a result the suction pressure can be higher than the pressure in the oil reservoir. The two-way valve RV2-10B-1,5-2W, which has been especially designed for these conditions, allows the pressure equalization between the suction line and the reservoir if the excess pressure in the suction line is above 0.1 bar. As a result the oil reservoir pressure will never be significant lower the suction line pressure.
The use of the RV2-10B-1,5-2W ensures that required pressure difference for the oil return will always be established with a short time.

Technical specification
Max. allowable operating pressure [PSmax 53 bar
Max. allowable operating temperature: 100°C