Mack MRU - Before Performing Maintenance on the Lng or Cng Tanks or Fuel System; Removing Pressure before Working on the Engine Fuel System

MAINTENANCEANDLUBRICATION29
BEFOREPERFORMINGMAINTENANCEONTHE
LNGORCNGTANKSORFUELSYSTEM
Note:Separatemethanedetector/alarmsystemsshouldbeinstalledinfacilitiesthat
frequentlyhouseLNG/CNGvehicles.Inaddition,hand-heldmethanedetector/alarm
devicesshouldbeusedwhenworkingonLNG/CNGvehicleswithanon-functioning
ordisconnectedmethanedetector/alarmsystemandwherenoauxiliarymethane
detector/alarmsystemisinstalled.
CAUTION
Beforeperforminganymaintenanceon
theLNG/CNGtanksystem,refertothe
tankmanufacturer’soperationmanual.
WARNING
REMOVEPRESSURE.Before
workingontheLNG/CNGfuelsystem,
closethefuelvalvesoneachtankand
relievethepressureinthefuellineby
openingthedrainonthefuellterorby
runningtheengineuntilitstops.
TheLNG/CNGfuelsystemsare
pressurizedsystems.LNGwillboiland
causepressuretobuildinthesystem.
DoNOTallowLNGtobecometrapped
inpiping,asbetweentwoclosedvalves.
Itwillvaporizeandrapidlyincrease
pressure,burstingthepipe.
RemovingPressureBeforeWorkingontheEngine
FuelSystem
BeforeservicingtheLNG/CNGenginefuelsystem,removepressurefromthefuel
linesbyturningthevalvesoneachtanktotheOFFposition.Thiswillstopmorefuel
fromenteringthelinestotheengine.Allowtheenginetorununtilit"dies."