Brochure

Flo-Con Pressure Regulators and Valves
Parker Hannifin Corporation
Climate & Industrial Controls Group
Cleveland, OH
341
Catalog CIC-2003-1/US
Flo-Con Pressure
Regulators
& Valves
Crankcase Pressure Regulators
Crankcase pressure regulators, also known as “CPRs”
or “holdback” regulators, are outlet pressure regulators
installed in the suction line which prevent an excessive
downstream pressure regardless of fluctuations in load
or inlet conditions. R/S types A8AOE, A810E, and
A82OE comprise the line of commercial outlet pressure
regulators that can be applied as crankcase pressure
regulators.
When system conditions occur that allow suction
pressures to increase appreciably above normal oper-
ating levels, a crankcase regulator should be applied.
Without a downstream regulator, which effectively
throttles down the suction pressure to the compressor,
a compressor motor overload condition can occur.
Such conditions are likely during pull down after a hot
gas defrost period, or during system start-up. An
A8-OE outlet regulator will gradually close when the
downstream pressure begins to rise above the valve’s
set point, and will gradually open when the outlet pres-
sure falls below its set point, effectively preventing the
compressor suction pressure from exceeding the
regulator’s set point.
No crankcase regulator can maintain its set for
pressure if branch lines feed into the main suction
line downstream of the regulator. For that reason, it
is important that no lines feed into the suction line
between the regulator and the compressor.
(For sizing, please reference suction capacity charts for
A8 regulators on pages 290 through 297.)
Figure 6 - Crankcase pressure regulator application. (See page 346 for symbol legend)
Technical Information Crankcase Pressure Regulators
Label Valve Function Application Design
Selection
Page
A Outlet Pressure Regulator Crankcase Pressure A8_OE 290-297
B Solenoid Valve Liquid Feed SC 342
Valve Legend