Page 46 - WM E-Learning Handbook

Slide Topic Content Notes

Primary Pressure Relief  Prevents tank from over-
Valve pressurization

 Activates at 230 psi
 Self-resetting

Secondary Pressure Relief  Activates at 350 psi
Valve  Redundant pressure relief
 If red cap is missing, do not refuel

Vent Valve  Used during fueling to reduce
Fuel Gauge Sender pressure inside LNG tank to allow
fueling

 Vents vapor back to fueling station
 Also used to reduce pressure inside

the tank for maintenance

 Sends signal to the fuel gauge on
dash of vehicle to indicate the
quantity of LNG in the tank(s)

Pressure Control  Supplies vaporized LNG to heat
(Economizer) Valve exchanger when excess head
pressure exists in tank
Internal Check Valve
 Controls flow toward engine
Engine Coolant Heat  Closes at ~125 psi
Exchanger
 Located inside plumbing manifold
on tank

 Provides 2 psi back pressure
 Assists Pressure Control Regulator

in rapidly reducing tank pressure

 Warms LNG, changes state from
liquid to gas

 Uses heat from engine coolant for
warming

 Warms gas to the engine, typically
130-170°F

Technician Safety and Awareness Training for NGVs © 2018 NGVi All Rights Reserved Page 44