MAHLE RTI RRC750X - Manual (Page 11)

Refrigerant Technologies, Inc.
May 24, 1993 Page 10
Refrigerants react with water to form hydrochloric and hydrofluoric acids which are corrosive to
equipment and contaminate oil. Removal of acid at this stage is important to protect the Compressor
and other RR750X components.
The Acid Filter must be replaced after every 500 hours of operation.
CHECK VALVE (1 PSI)
The Check Valve permits forward refrigerant flow when the output pressure from the Acid Filter is
1 lb. or greater than pressure at the output side of the Check Valve. The primary purpose of this
check valve is to prevent flow of oil backwards towards the Acid Filter during the Oil Return Cycle
from the Oil Separator.
SUCTION SHUTDOWN SOLENOID VALVE S-11
Prevents flow of refrigerant to the Compressor when not operating.
SUCTION PRESSURE REGULATING VALVE
This valve is sensitive only to the pressure at the outlet port. The pressure range at which the valve
is open is increased or decreased by adjusting a spring which acts on an internal bellows.
Inlet pressure to the valve is exerted on the bellows and the top of the seat disk. Since the effective
areas of the bellows and seat disk are equal, the inlet pressure has no affect on the valve operation.
The output pressure of the valve acts on the underside of the seat disk and exerts a pressure in the
closing direction. This force is opposed by a spring which is adjusted to set the pressure at which
the valve closes.
During production of the RR750X, this valve is adjusted to limit the mass flow rate to 10 ± 2 PSIG
during normal operation.
COMPRESSOR
Refrigerant is compressed, resulting in an increase of temperature. This temperature rise is due to
the total heat of the vapor being squeezed into a smaller space.
The compression of gaseous refrigerant in a compressor is considered to be near a state of Adiabatic
Compression. Adiabatic refers to the process whereby a gas is compressed (or expanded) without
any transfer of heat into it during the compression (or expansion).
A very slight increase in temperature may be due to frictional heat generated within the Compressor.
A sight tube is mounted on the Compressor for monitoring the oil level. The Maintenance Section
of this manual describes procedures for adding oil as required.