k. | Low suction pressure and low to normal head pressure | k. | Evaporator restricted |
| High superheat and normal to high subcooling |
|
|
l. | Low suction pressure and normal head pressure | l. | Expansion valve restricted |
| High superheat and normal subcooling |
|
|
m. Low suction pressure and high head pressure | m. Both evaporator and condenser | ||
| High superheat and high subcooling |
| restricted |
n. | Low suction pressure and high head pressure | n. | Liquid line restricted before |
| High superheat and high subcooling |
| receiver |
o. low to normal suction pressure and high head pressure | o. | Condenser restricted | |
| High to normal superheat and high subcooling |
|
|
|
|
|
|
3. Valve Operation
SPINDLE BACK POSITION SPINDLE FRONT POSITION SPINDLE MIDDLE POSITION
Fig. 4.1 Valve Operation
Back Position: Process and manometer port closed for normal operation
Front Position: Main connection to liquid or suction line closed
Middle Position: All ports open for vacuum, charge and measurement
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