NSTM Chapter 541, Ship Fuel and Fuel Systems Flashcards
F-76 was previously known as ___
DFM
The only aviation jet fuel authorized to be carried by fleet oilers and used aboard navy ships
JP-5
Handles ship fuel from the time it is received aboard the ship until it is consumed by propulsion and auxiliary equipment
Fuel system
Provides fuel to propulsion equipment such as boilers, diesel engines, and gas turbines, as well as to auxiliary equipment
Service system
Ships with more than one propulsion space usually have a ___ fuel system
Separate
Usually at least ___ service pump and ___ service tanks serve each propulsion service system
2
2
How many service tanks are used at one time?
One
Takes suction from any storage tank or contaminated oil settling tank and delivers fuel, usually through filtration equipment, to a service tank
Fuel transfer pump
Draws contaminated liquid from the tank bottoms and delivers it to a COST
Stripping pump
COST
Contaminated Oil Settling Tank
___ ships with ____ have no separate stripping systems
Gas turbine
Seawater-compensated storage tanks
Most significant hazards of fuel
Flammability
Toxicity
Pressure
Enhance ship’s stability and trim by ___
Keeping fuel properly distributed among storage tanks
Minimizing the number of partially fill uncompensated tanks, to reduce free surface
Ballasting storage tanks when necessary
Fuel system operations that affect stability include ___
Fueling, transferring, ballasting, and deballasting
Onboard provisions for cleaning fuel
Storage tank stripping Transfer system filtration Service tank stripping Service tank recirculation Service system filtration
Service system filtration. Steam ships typically use a ___; diesel engine ships use ___; and gas turbine ships use ____
Strainer
Filter attached to the engine
Filter/separator
Remove free water as well as fine particles
Filter/separator
Many gas turbine ships have a ___ upstream of the filter/separator
Pre-filter
Transferring fuel from one underway ship to another underway ship
Fueling at sea
Lowest temperature at which the fuel gives off enough vapor to form a mixture with the air that is capable of being ignited by any ignition source
Flashpoint
___ are hazards of fuel below the flashpoint
Wicking and mist formation
Lowest temperature at which the fuel will ignite in air without a spark or flame
Autoignition temperature
Autoignition temperature is also called ___
Autogenous ignition temperature
AIT
Autoignition Temperature
AITs as low as ___ have been measured for F-76 and JP-5
450F (232C)
Surfaces hotter than ___ generally are required to be insulated to protect personnel
125F (52C)
Every effort shall be made to prevent fuel from dripping or spraying onto any hot surface of ___ or higher
400F (204C)
When fuel is drawn onto an absorbent solid material that can be ignited locally
Wicking
Fuel soaked clothing can be a hazard for ___
Days
How shipboard fuel fires start
Fuel leaks
Fuel spray
Fuel accumulation
Any unintended release of fuel
Fuel leak
Most dangerous kind of fuel leak
Fuel spray
How to prevent shipboard fuel fires
Separation
Good maintenance
Basic principle of preventing shipboard fuel fires
Keep fuel and ignition sources away from each other
When looking for fuel sprays, pay particular attention to ___
Piping and joints near hot surfaces
Do not paint nonferrous and corrosion resistant steel piping and valves in ____ areas
Nonbilge
Inspections of fuel tanks for leakage should include ___
Manhole covers and external sounding tubes
Soft patches on fuel piping shall be reported by ___
Departure From Specifications (DFS) request
When assembling fuel system joints, always use ___
New gaskets
The presence of fuels in the bilge can be detected by ___
Spreading a thin coat of water indicating paste on one side of a metal rod, and fuel indicating paste on the other side
Pump oily waste from bilges using the ___
Oily waste transfer system
Do not light off boilers, diesel engines, or gas turbines when oily waste is ___
In the bilges or on nearby deck plates
When boilers are secured and will not be lit off within ___, drain fuel from the torch pots
24 hours
The lighting-off torch pot shall be ___ in front of each boiler
Welded or bolted to a structural member of the deckplating
Fuel on deck place is a ___ hazard
Fire and slipping
Detect flammable gases and vapors
Combustible gas indicators
Fuel tanks are considered ___
IDLH
No person shall enter a tank known or suspected to contain fuel or fuel vapors at any time without first having received permission to enter such a tank from the ___
CO
Before granting permission to enter a tank that may contain fuel or fuel vapors, the CO shall ___
Ensure safety precautions and instructions in NSTM Chapter 074, Volume 3 are carried out and that personnel supervising the entry are familiar with these instructions and precautions
Make no repairs involving hot work near fuel tanks and piping without a ___
Hot work permit
Avoid using ___ lights near fuel tanks or during repairs in engineering spaces that have not been declared gas free
Portable electric
When portable electric lights must be used near fuel tanks or during repairs in engineering spaces that have not been declared gas free, fit them with ___
Explosion proof enclosures and heavy wire guards, and test them for complete insulation
Required for sounding tubes that terminate in hazardous areas
Sounding tube floating-ball check valves
Prevents fuel from spilling from the sounding tube if the tank is overfilled while the sounding tube is open
Sounding tube floating-ball check valves
Required for flanged connections in locations identified in NSTM Chapter 505
Flange spray shields
Prevent fires caused by poor joint assembly, gasket failure, or improper torquing of fasteners
Flange spray shields
Capture any fuel spray from the joint and cause it to drip or dribble to a safe location instead of spraying onto nearby hot surfaces
Flange spray shields
Emergency cutout valves are required for ___
Casualty control
Provide various ways to quickly shut off the fuel flow in the service system, either locally or outside the space
Emergency cutout valves
Required for motor-driven fuel service pumps
Service pump remote shutdown pushbuttons
Service pump remote shutdown pushbuttons are located ___
Outside the space for casualty control
Required for all service system strainer, filter/separator, and pre-filter covers
Integral cover fuel spray deflectors
Direct any fuel that leaks past the cover gasket or o-ring downward, where it is less likely to strike a hot surface
Integral cover fuel spray deflectors
All sampling and vent connections inside the ship shall discharge ___
Downward into a funnel
Sampling and vent connection funnels shall direct the fuel to ___
Oily water drain collecting system
__ shall be provided over any hot surfaces under the sampling and vent connection funnels
Spray shields
Provided at all sampling connections
Sampling connection cutout valves
Boiler front connections have been provided with ___
Two cutout valves in series
Fuel sampling connections shall not have ___
End caps
Why should fuel sampling connections not have end caps?
Pressure can build under the end cap if the sample valve leaks, causing a momentary fuel spray when the cap is removed
___ shall replace old-style rubber lined butterfly valves in fuel systems whenever possible
High-performance butterfly valves
Provided in air escapes of fuel tanks to retard flashback if the system is accidentally exposed to an ignition source
Vent/flash screens
____ has replaced the Firesafe F/O Strainer (FSFOS) for purposes of simplicity
Hellan Simplex Strainer
___ Strainer is equipped with a hand wheel that allows the operator to turn the integral basket element against a stationary scraper blade in order to remove accumulated sediment on the exterior of the strainer basket element. The sediment is then flushed to a drain line
Hellan Simplex
Hold fuel as it is loaded onto the ship, before it is cleaned for use by propulsion and auxiliary equipment
Fuel storage tanks
The three kinds of fuel storage tanks differ in the way ___
Seawater ballasting is related to fuel storage and ship stability
Three kinds of fuel storage tanks
Separate fuel tanks and ballast tanks
Fuel or ballast tanks
Seawater-compensated fuel tanks
Incorrect handling of the fuel also affects operating fuel economy if storage distribution causes ___
Drag in excess of intended trim
__ is responsible for the ship’s loading and ballasting
Damage Control Officer
Fuel storage and ballasting methods apply only to fuel ___, never introduce seawater into fuel ___
Storage tanks
Service tanks
Rated capacity of a fuel storage tank that is not sea-water compensated is ___
95% of its total capacity
The remaining 5% in a fuel storage tank rated capacity is reserved to ___
Allow the fuel to expand
Do not fill uncompensated fuel tanks, not designated as an overflow tank, to more than ___ of capacity in port or at sea
95%
Do not fill uncompensated overflow tanks above ___ of capacity at sea, or ___ in port
95%
80%
In this system fuel storage tanks and seawater ballast tanks are completely separate
Separate fuel tanks and ballast tanks
Ballast seawater form separate ballast tanks that never contain fuel can be discharged within ___ because the ballast seawater ___
Prohibited zones
Contains no fuel
Primarily separate fuel and ballast system, but if the fuel load falls below a certain point and additional ballast is required, designated fuel tanks may be ballasted with seawater
Modified clean ballast system
This system has no separate seawater ballast tanks
Fuel or ballast tanks
In a fuel or ballast tank system, the ballast seawater is introduced by the ___ through separate tailpipes and is removed by the ___
Firemain
Main drain eductors and the stripping pumps
Never ballast a fuel tank until ___
It is completely empty of fuel
Ballast seawater in a fuel tank is considered ___
Oily waste
To avoid drawing silt or other contaminants into the tank, do not utilize ___ as ballast seawater in any fuel tank
Harbor water
Ballasted fuel tanks whose tops are above the transfer system manifold have a ____ between the tank bulkhead isolation valve and the manifold
Pipeline sample connection
If seawater is detected in the fuel transfer system, take samples from the sample connections at all ballasted tanks. If any sample contains seawater, then ____
The isolation valve at that tank is probably leaking
____ fuel storage tanks are always completely full of liquid
Seawater-compensated
Ballast seawater enters tanks as fuel is removed, and is displaced overboard as fuel is added
Seawater compensated fuel storage tanks
The fuel and the seawater tend to remain separate because of ___
Differing specific gravities
The types of fuels used onboard naval vessels are ___ than seawater
Lighter
Storage tanks are connected in ___
Banks
In an tank bank, the transfer system is connected to the top of the ___
First tank
The first tank in the bank is called the ___
Receiving tank
The ___ of each tank in the bank is connected to the ___ of the next tank through a ____
Bottom
Top
Sluice pipe
The bottom of the last tank in the bank is connected to the top of the ____
Expansion tank
The overflow piping runs from the bottom of the ____ up to ___
Expansion tank
Overboard discharge connection and an overflow
The ____ in the overflow piping keeps the liquid in the storage tanks under pressure
Seawater standing
On ships with stripping tanks, personnel shall check ____ prior to filling
Stripping tank sight glass
The transfer system draws fuel from ___
The top of the receiving tank
___ is discharged when fuel is added to a tank bank
Seawater
Butterfly valves with holes drilled through the disc. In the closed position these valves limit the flow of fuel into each tank to approximately 400 gal/min
Inport refueling valves
Do not use ___ to blow seawater from compensated tanks
Air pressure
In a tank bank, pump out the ___ first, because it is always ____
Expansion tank
Higher than the other tanks
Fill the last fuel tank in a compensated tank bank to only ___ when in port and ___ when at sea
80%
95%
Tanks that overflow directly overboard shall have __
High level alarms
Avoid refueling or transferring fuel at ___
Night
Purifier pumps have a ___ flow capacity than transfer pumps
Lower
Use the ___ pump for transfer between storage tanks and for defueling
Transfer
Use the ____ pump for transfer from a storage tank to a service tank
Purifier
Smaller ships have a deck connection designed for a __ hose, capable of passing ____
2-1/2 inch
200 to 250 gpm
To minimize system resistance and thus maximize filling rate, align the transfer system to ___
Fill as many tanks at once as possible
As each tank approaches full ___
Throttle the flow into the tank
___ each tank before fueling
Check the level
Check tanks by ____ rather than with ___
Sounding
TLIs
When the tank is first being filled, take soundings every ___
3 or 4 minutes
After the tank reaches ____, take soundings continuously until full
3/4 full
____ after each sounding to minimize the fuel vapors entering the space and to prevent a fuel spill if the tank overflows
Replace the sounding tube cap
Reasons to consolidate fuel
Move weight for list and trim
Reduce free surface
Speed up fueling
On ships with seawater-compensated tanks, remove the fuel ___
Evenly
Do what to the tanks before transferring fuel
Sample and strip
Some transfers between uncompensated tanks can be accomplished by gravity if ___
The liquid level of the supply tank is higher than the liquid level of the receiving tank
If the ship has multiple transfer pumps, use the pump ___
Closest to the supply tank to minimize suction requirements
Before starting the transfer pump, perform ___
System operational integrity test
Steam ships have strainers in their ___
Service tank fill lines
Ships with purifiers have ____ upstream of the purifiers to reduce the viscosity of F-76 for optimum purifier operation and to prevent fuel from ___
Fuel heaters
Waxing
Because of JP-5’s overall characteristically lower viscosity and freeze point (cloud point for F-76) at any given temperature compared to F-76, it is not necessary to ___ JP-5
Heat
If heating is not required, route the fuel through a ____
Heater bypass valve
Heater installations include ___
High-temperature alarms and relief valves
Fill service tanks as soon as ___
Suction has been switched to the standby service tank
Do not fill a service tank that is ___
Being used to supply fuel to the service system
Conduct all transfer operations according to the ship’s ___
EOSS procedures
This test provides a quick check on system alignment, to verify that fuel is not being delivered to an unintended destination
System preoperational integrity test
Run this test during the startup of transfer operations for ships with strainers or filters
System preoperational integrity test
Do not accomplish the system preoperation integrity test with alignments that pass fuel through ____, because ____
Purifiers
The high back pressure will impede the proper fuel flow through the purifier
Primary purpose of the system preoperational integrity test
Detect misalignments
The system is correctly aligned if the pressure ___
Approaches its rated maximum
If the pump discharge pressure never approaches its rated maximum, even with the receiving tank inlet valve closed, then three possibilities are ___
Unintended open valve
Pump relief valve that has failed in the open position
Major system leak
If system flow cannot be established within ___ after the pump is started, stop the pump
1 minute
If the strainer was cleaned since the last time is was pressurized, the strainer shall be ___ before the system preoperational integrity test is completed
Pressure tested for leaks
Stop the pump when the service tank is ___ full
95%
Log the differential pressure readings across the filter/separator in the ___
Fuel transfer log
The transfer system is aligned to recirculate fuel back to the suction side of the transfer/purifier pump via a three-way inlet valve to allow the purifier and heater to ___
Reach steady-state operation
If the purifier fails to start, allow it to ___ before trying to restart it
Coast to a complete stop
To avoid overheating, ___ before power is applied or steam is admitted to the heater
Fuel must be flowing through the heater
The bowl of the self-cleaning purifier is periodically cleaned by a ___
Shoot cycle
In a shoot cycle, the diverter valve upstream of the purifer redirects fuel flow ____ instead of into the purifier, and the purifier ____
Back to the pump suction
Discharges solid contaminants from the bowl
All fuel vents and drains are directed to the ___
Oily water drain collecting system
Vents often terminate at ___
Drip pans
Provides fuel from the service tanks to the ship’s propulsion and other equipment
Fuel service system
EOSS
Engineering Operational Sequencing System
Fueling operations shall always be conducted according to the ___
Ship’s EOSS procedures
Piping arrangements for returning unneeded fuel to the service tanks depends on whether ___
Pumps are motor driven or turbine driven
If the service pumps are driven by motors, a ___ controls the amount of fuel returned to the service tank on suction
Pressure regulating valve
The pressure regulating valve in a motor driven service pump is called ___
Unloading valve
Maintains a constant pressure downstream of the pump
Unloading valve
Fuel must be returned to the service tank because motor-driven service pumps move a ___
Constant flow
If the service pumps are turbine-driven, the ___ adjusts pump speed to maintain a constant fuel discharge pressure
Turbine constant-pressure governor
Use the online tank until it is ___ full, then put the standby tank online
50%
Before putting a service tank online
Test the fuel
When the service tank in use is changed, fill the new standby tank ___
As soon as possible
Stops fuel flow into the system from the service tank
Service tank suction cutout valves
Surest way to stop a leak anywhere in the system
Close or trip the service tank suction emergency cut out valve
Steam ship service pumps are driven by either __
Steam turbines or electric motors
How many pumps are provided in each space on a steam ship?
2
Service pump turbine governors adjust steam flow to maintain a ___
Constant fuel pressure downstream of the pump
If the main service pumps are turbine driven, an ___ is usually included
Electric inport service pump of lower flow capacity
___ is intended to supply fuel to a boiler while inport or for lighting off the first boiler in a space
Inport pump
___ are used to clean the fuel in steam ship service systems
Simplex or duplex filters
___ configuration allows for switching flow from a dirty basket to a clean basket, without interrupting the flow of fuel to the boiler
Duplex
Utilize a simplistic design using a hand wheel to rotate the basket element against a stationary scraper blade to remove accumulated sediment contaminants
Simplex strainer
Discharge pressures from motor driven service pumps are controlled by the ___
Unloading valve
Discharge pressures from turbine driven service pumps are controlled by the ____
Turbine constant pressure governor
The turbine constant pressure governor senses ___
Pressure in the fuel line downstream of the pump
Service pump discharge pressures are typically ___
350 lb/1in² to 430 lb/in²
Pressure in the boiler manifold is controlled by the ___
Boiler fuel control valve
Pressure in the boiler fuel manifold is always ___ to the service pump discharge pressure
Less than or equal
Many diesel engine return lines include coolers that cool the fuel to approximately ___
110F (43C)
Excessively warm fuel will ___
Not cool the injectors effectively and could begin vaporizing in the engine fuel system before reaching the injectors
Engines with no coolers in the return lines have ___
Sufficiently long lines and large service tanks to prevent fuel from becoming too warm
If an engine has to be serviced while other engines in the space are operating, ___
Isolate the fuel lines to and from the engine being maintained
Service tanks are located so that fuel pump inlets are ___
Flooded when the tanks are full
If the diesel engine is for an emergency generator, the engine systems should be aligned for ___
Automatic starting
In gas turbine ship service systems, the pumps act as ____
Booster pumps
Gas turbines have their own attached fuel pumps that ___
Increase the fuel pressure to that needed for the combustors
Service pump discharge pressures in a gas turbine are typically ___
55 psig
Overall coordination and control for gas turbines emanates from the ___
Central control station
Start the service pump at ___
Slow speed
The ___ fills the service tanks
Transfer system
The service tanks are considered part of the ___ system
Service
In an emergency, service pumps on steam and gas turbine ships can take suction directly from the ___, usually through the ___
Storage tanks
Transfer system main
The connection to the transfer system for drawing fuel directly from storage tanks is usually ___
Locked closed
Removes water and sediment from the bottoms of fuel tanks
Fuel stripping system
Contaminated fuel in tanks or service system piping is usually stripped to the ____
Contaminated oil settling tank
Lowest tailpipes in a tank
Stripping tailpipes
Stripping tailpipes are ___ from the lowest point in the tank
3/4”
In configurations where two-speed dual purpose, transfer/stripping pumps are used, a ____ is installed on the tank bottom directly beneath the tailpipe terminus
Doubler plate
Two reasons to pump contaminated fuel to the COST
Avoiding pollution
Reclaiming fuel
Leave contaminated fuel in the COST for ___
As long as possible
Keep bilge fluid or any other fluid that may contain ____ other than the ship’s fuel from entering the COST
Hydrocarbons
___ storage tanks do not a low-point stripping tailpipes
Seawater-compensated
The pressure boundary of an operating fuel system shall not be broken except for ___
Extraordinary situations
The ___ permission is usually required for single-valve isolation of a pressurized fuel system
COs
If the pressure boundary of the system has been opened and then closed, a ___ is often required on the affected portion of the system
Hydrostatic test
Verifies that the system is not leaking and is capable of holding and maintaining pressure
Hydrostatic test
When conducting a hydrostatic test on a fuel system, be prepared to ___
Fight a bravo fire
Tightness test option for a reduced energy system is for systems operating at ___
200 psig or less and 200*F or less
If possible, perform the operational pressure test when the space is at ___
Cold iron
___ piping systems may require more flushing than stainless or copper-nickel systems
Carbon steel
___ will be used as the flushing fluid
F-76 or JP-5
If system pumps are to be used to circulate the flushing fluid, install __ to protect the pumps
Temporary suction strainers
During flushing, periodically ___ the system piping, especially near welded joints, by ___
Vibrate
Striking it with a wooden mallet or equivalent means
Flush the system for a minimum of ___ or until ___
24 hours
The muslin or nylon bags in the strainers show no appreciable contamination for two consecutive hours
When flushing is completed, transfer the flushing fluid to ___ or ___
COST
Empty storage tank
The flushing fluid shall discharge into the tank through a strainer having ___ openings
4-mil
Flushing is generally not required for ____
Stripping systems
Fuel systems take suction from tanks and discharge into tanks through ___
Tailpipes
