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Section 4 • Operation
VSS/VSR/VSM/VSH/VSSH Compressor • Installation, Operation and Service Manual • Emerson • 35391S
Suction Equalizing Line Setup - For
VSS/VSM Compressors
The suction equalizing line allows system pressure to
equalize to suction pressure during shutdown periods.
The line is connected before the suction stop/check
valve to after the suction strainer, see Figure 4-13.
NOTE
Valve adjustment depends on size of oil separator and
how quickly system pressure should equalize to suction
pressure. The larger the oil separator the longer system
pressure will take to equalize to suction pressure.
Figure 4-13. Suction Equalizing Line and Valve
Suction
Equalizing Line
Suction
Equalizing Valve
1. To open valve, turn counterclockwise. To close
valve, turn clockwise.
2. Fully close valve to a stop.
3. Turn valve to fully open position while counting
number of turns to fully open. Note total number
of turns.
4. Adjust valve to be half open. Close valve to half of
the number of total turns.
5. If suction pressure needs to equalize slower, turn
valve towards closed position.
6. If suction pressure needs to equalize faster, turn
valve towards open position.
NOTE
For VSH/VSSH compressors, suction
equalizing is automatically controlled.