Which operation may cause the pressure in an inert tank to fall below the prescribed limits ________．A.LoadingB.DischargingC.Crude oil washingD.Steaming tanks
Which operation may cause the pressure in an inert tank to fall below the prescribed limits ________．
A.Loading
B.Discharging
C.Crude oil washing
D.Steaming tanks
相关考题：
If the suction pressure for an operating refrigeration compressor is below normal, the cause may be ______.A.an excess of liquid refrigerantB.the expansion valve overfeedingC.a fouled compressor suction strainerD.the compressor short cycling
How does an inert gas system on a tanker function to prevent explosions in cargo tanks?A.De-energizes the "charged mist" effectB.Maintains a positive pressure on the vent header to cool the flammable vaporsC.Inert gas filters out the flammable vapors from the cargo tank spacesD.Inert gas dilutes the flammable vapor and air concentrations to keep them below the lower explosive limit
Which method is used to supply inert gas from a flue gas system to the cargo tanks?A.Exhaust gas pressure from the stackB.High capacity fanC.Inert gas compressorD.Natural aspiration
You are discharging cargo and the inert gas system is in operation to inert the tanks. The pressure in a tank being discharged starts to drop below the allowable limit. What action should you take?A.Cut in another IG fan to increase gas flowB.Open the pressure control valve until the pressure increasesC.Open the tank isolation valve to the fully open positionD.Reduce the pumping rate
By regulation，cargo tank atmosphere must be inert before and during which operation ________．A.StrippingB.LoadingC.CleaningD.All of the above
Inerting means ______．A.The introduction of inert gas into a tank with the object of reducing the oxygen content to below 8% by volumeB.The introduction of inert gas into a gas free tank for the purpose of reducing the oxygen content to below 8% by volumeC.The introduction of inert gas into a cargo tank during cargo discharge to replace the volume of discharged cargoD.All of the above
The use of portable electrical equipment in the pumproom on tank barges is prohibited unless ______．A.The pumproom is gas-freeB.Spaces with bulkheads common to the pumproom are either gas-free，inert，filled with water，or contain grade E liquidC.All other compartments in which flammable vapors and gases may exist are closed and securedD.All of the above
Which statement about inert gas pressures in a cargo tank is TRUE ________．A.The pressures of the inert gas in the tank may create excessive pressure at the pump while dischargingB.Gas pressures should be maintained at the highest permissible level throughout the discharging processC.High gas pressures may cause pyrophoric oxidation in the tankD.High gas pressures may cause loss of suction when stripping
An inert gas system is designed to reduce the possibility of tank explosions by ______.A.eliminating sparks and fire in the vicinity of cargo tanksB.removing all hydrocarbon gases from the cargo tanksC.blanketing cargo tanks with inert foamD.reducing the oxygen concentration below levels necessary for combustion
单选题How does an inert gas system on a tanker function to prevent explosions in cargo tanks? （）ADe-energizes the charged mist effectBMaintains a positive pressure on the vent header to cool the flammable vaporsCInert gas filters out the flammable vapors from the cargo tank spacesDInert gas dilutes the flammable vapor and air concentrations to keep them below the lower explosive limit
单选题Petroleum cargo tanks should not be topped off at deck level when loading on a cold day because（）.Aa subsequent temperature rise will cause the cargo to overflowBair pockets may cause the cargo to bubble out of the ullage holeCthe increased viscosity of the product requires higher loading pressure which increases the chances of a spillDthe tank valve may be stiff and a spill will occur before the valve can be closed
单选题Which of the conditions listed would cause simultaneous high cylinder firing pressure and low exhaust temperature?（）AImproper fuel rack positioningBLengthy opening of the exhaust valveCExcessively early injection timingDExtended light load operation
单选题The domestic fresh water pump starters are controlled by pressure switches which operate when the pressure in the tank varies within predetermined limits as water is drawn offThe word “which” means （）.AstartersBpressure switchesCpressureDwater
单选题The atmosphere in a tank is too lean if it is（）.Aincapable of supporting combustion because the hydrocarbon content is below the LFL (Lower Flammable Limit)Bcapable of supporting combustion because the hydrocarbon content is above the UFL (Upper Flammable Limit)Ccapable of supporting a fire once startedDnot safe for ballasting
单选题An inert gas system is designed to reduce the possibility of tank explosions by（）.Aeliminating sparks and fire in the vicinity of cargo tanksBremoving all hydrocarbon gases from the cargo tanksCblanketing cargo tanks with inert foamDreducing the oxygen concentration below levels necessary for combustion
单选题If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.Arefrigerant overchargeBoverfeeding by the expansion valveCa restricted suction strainerDdue to short cycling of the compressor
单选题By regulation，cargo tank atmosphere must be inert before and during which operation?（）AStrippingBLoadingCCleaningDAll of the above
单选题Which action must be taken when an individual cargo tank is closed off from the inert gas system by the tank isolation valve?（）AThe tank must be gas freedBThe tank must be ballastedCThe tank must be vented to the atmosphereDThe bypass valve must also be closed
单选题Why is it important for fuel oil tanks not to be topped off at the inner bottom level when loading on a cold day?（）AIncreased viscosity of the product needs higher loading pressure, which increases the chances of a spillBAir pockets may cause the fuel to bubble out of the ullage holeCThe temperature rise of the fuel will cause an overflowDFueling valve may become stuck closed and cause the fuel oil to spill before the valve can be opened
单选题Which of the following may cause that the compressor cuts off on high pressure cutout in a refrigeration plant? （） (1) faulty condensing (2) too few refrigerant (3) high discharge pressureAany of (1) and (3)Bany of (1) and (2)Cany of (2) and (3)Dany of (1), (2) and (3)
单选题You are discharging cargo and the inert gas system is in operation to inert the tanks. The pressure in a tank being discharged starts to drop below the allowable limit. What action should you take? （）ACut in another IG fan to increase gas flowBOpen the pressure control valve until the pressure increasesCOpen the tank isolation valve to the fully open positionDReduce the pumping rate
单选题Inerting means（）.Athe introduction of inert gas into a tank with the object of reducing the oxygen content to below 8% by volumeBthe introduction of inert gas into a gas free tank for the purpose of reducing the oxygen content to below 8% by volumeCthe introduction of inert gas into a cargo tank during cargo discharge to replace the volume of discharged cargoDAll of the above
单选题Which of the following conditions can cause below normal air pressure in the intake manifold of a turbocharged diesel engine?（）AExcessive piston blow-by to the manifoldBInsufficient cooling water flowCAccumulated water in the air boxesDClogged air intake filters
单选题A crew member reports that the high-pressure alarm light of a low-pressure CO2 fixed fire extinguishing system is illuminated. The most probable cause of this condition would be that（）.Aan air leak has developed in the tankBthe tank cooling system has malfunctionedCthe pilot cylinder discharge valve is leakingDan excessive amount of insulation has been installed on the tank and piping
单选题An inert gas system on a tanker should be used to（）.Aprevent the generation of flammable or combustible gas in tanksBblow out cargo lines to prevent the build up of gas concentrationsCdilute tank atmospheres to keep gas concentrations below the lower explosive limitDprevent fires in the pumproom by continually displacing flammable vapors
单选题An inert gas system on a tanker should be used to（）.Aprevent the generation of flammable or combustible gas in tanksBblow out cargo lines to prevent gas concentrationsCdilute tank atmospheres to keep gas concentrations below the lower explosive limitDprevent fires in the pumproom by continually displacing flammable vapors
单选题Which operation may cause the pressure in an inert tank to fall below the prescribed limits（）.ALoadingBDischargingCCrude oil washingDSteaming tanks