A dry gas seal.
Typical problems encountered in lube oil and dry gas seal systems are given below:
Lube oil system
Reservoir: heater damage, insufficient heating for cold starts or poor thermostat control
High water content in reservoir
Collapsed filter cartridges during low ambient temperature start-ups
Steam turbine main pump driver – poor reliability (frequent trips, H20 in oil)
Unit trip or system instability during auxiliary oil pump start
Low lube oil pressure trip during auxiliary oil pump start or low oil pressure trip when aux pump is shut off with main running
High oil filter delta P
Poor oil temperature control
Transfer valve damage / idle side leakage
Bearing damage during Plant Black incident
Seal oil system
Low oil flash point or loss of viscosity index
Seal oil system instability or trips as a result of reference pressure changes
Sleeve seal overhead tank response time
Excessive contaminated seal oil leakage rates
Contaminated seal oil drainer failure to drain
Oil ingestion into the process
Control oil system
System instability following control valve movement
Unit trip during system upset
Inability to maintain accumulator pre-charge
Auxiliary oil pump start during ramp up
System instability during auxiliary oil pump start
Dry gas seal system
Primary seal failure due to reverse pressurization
Process contamination during settleout
Increase in settleout pressure as unit awaits restart
Barrier seal excessive wear
Primary / secondary seal excessive wear during coastdown
Barrier seal oil ingestion
Excessive filter change outs during commissioning
Primary seal increase in leakage over time
Secondary seal failure due to liquid ingestion
Primary / secondary seal failure due to extended turning gear or crank time
Secondary seal fugitive emissions
High secondary seal vent flow.
