Emerson VSG Theory of Operation, Gas Flow, Oil Life and Oil Flow, 1. Gas Compressor Unit P&ID

Section 2 • Theory of Operation

1 2 3 4 5

SUCTION GAS						6
		TE				CHECK DISCHARGE
						VALVE	STOP VALVE
	1/4” OIL CHARGING
		COMPRESSOR			TE
BLEED
	MOTOR					1/4”
				14	13
		BLEED
15						OIL SEPARATOR
		TE		12
FILTER					11
		STANDARD SINGLE				TE
	BLEED				DRAIN
		OIL FILTER				100#
	DRAIN					MOTOR	7
		BLEED			M
						FG
						1
						PUMP
FILTER	DRAIN
						8
		FILTER
OPTIONAL DUAL OIL FILTERS			DRAIN

10

9

OPTIONAL REMOTE AIR COOLED OIL COOLER

	VENT
	OIL COOLER
OIL	DRAIN
DRAIN

STANDARD WATER COOLED OIL COOLER

Figure 2-1. Gas Compressor Unit P&ID

The gas and oil systems work in unison, but each one will be explained separately. Reference Figure 3 - Gas Compressor Unit P&ID for gas and oil flow descriptions.

Gas Flow

The gas compression process begins as processed gas enters the suction inlet (1). The processed gas flows through a stop valve (2), check valve (3) then through a suction line strainer (4) to the compressor (14). The processed gas is then pressurized through the compres- sor and discharged as high pressure gas vapor into the oil separator (13). In the oil separator, the oil is then separated from the discharged gas vapor by impinge- ment separation. The high pressure gas flows out to

the aftercooler and scrubber for cooling while the oil is pumped or syphoned back to the compressor.

Moreover, check valves (3) and (6) are provided between the oil separator to prevent gas vapor or liquid from flow- ing back to the compressor during shutdown periods.

An equalizing line is also installed between the high pressure side (oil separator) and low pressure side (suc-

tion) to allow .

Oil Life and Oil Flow

The life of the oil is directly affected by the quality of the gas. Proper separation of any liquids must be accom- plished to prevent droplets of liquid at the compressor

VSG/VSSG • Installation, Operation and Maintenance Manual •Vilter/Emerson • 35391SSG 2 – 1