| |
Equipment |
How it works |
Benefits |
Drawbacks |
| Storage
Tanks |
Vertical, from 6,000
to 30,000
(22,700 to 113,500 L) |
Vertical Storage Tank |
Thermosiphon Tanks
Piping, valves and assorted trim |
Smallest footprint
Lower cost
|
Tanks will be 40 to
50 feet high |
Horizontal, from
6,000 to 30,000
(22,700 to 113,500 L) |
Horizontal Storage Tank
|
Thermosiphon Tanks
Piping, valves and assorted trim |
Meets height restrictions
that apply in certain locations |
Requires large containment
area and large concrete pad |
Underground Horizontal,
from 20,000 to 30,000
(75,700 to 113,500 L) |
Horizontal Storage Tank |
Piping, valves and assorted
trim |
Meets permitting restrictions
for sites close to airports |
Requires more civil
work
Requires inspection
every five years to be sure tank is not leaking
May require boost pumps
|
| Site
Containment |
| At Grade Containment |
Grade level with walls
or trenches to contain spills |
Contains spill from
10,000 gal. (37,850 L) tanker. Spill dissipated to atmosphere |
Lowest cost |
Requires a much larger
footprint for LNG site
More difficult to recover
LNG
|
| Below Grade Pit Containment |
Sump pump required for
rain water |
Pit contains LNG spill |
Most effective way
to contain a spill per NFPA
Easiest clean up
|
More stringent site
requirements |
| Offloading |
| Pressure Transfer |
Offloading Connections
|
Vaporizers on tanker
Raise tanker pressure
until it overcomes storage tank pressure
|
Lowest cost, no additional
pumps required |
Can take two hours
or more to offload
Significant losses
in LNG during transfer
|
| Multi-Function Pump
Skid |
Offloading Connections
Multi-Function Pump
Skid
|
Pump-assisted offloads
Pump also used as dispensing
pump
|
Cut offload time to
less than two hours |
Can’t dispense
while offloading |
| Dedicated Offloading
Pump Skid |
Offloading Connections
Offloading Pump Skid
|
Pump-assisted offloads
|
Large volume. Cuts offload
time by 1 hr. Can dispense while offloading if LNG is saturated
properly |
Requires an additional
pump skid
Short cool down cycle
required
|
| Separate Receiving
Tank |
Offloading Connections
Offloading Pump
Additional Storage Tank and Distribution Pump Skid |
Receiving tank distributes
LNG to tanks that feed dispensers |
Allows offloading and
uninterrupted 24/7 fueling |
Most expensive option |
| Dispensers
|
Wall Mount
± 10% accuracy |
Dispenser Model D4 |
Variable frequency drives,
pump and dispensing nozzles controlled by the main LNG system PLC |
Low cost |
Fueling lane must be
adjacent to station
No composition compensation
for flow rates
|
Remote or Wall Mount
± 1.5% accuracy |
Dispenser Model D10
|
Variable frequency drives,
pumps and dispensing nozzles with a dedicated metering controller
and dispenser PLC |
Can be located on a
remote fuel island
Weight and measures
metering
|
Higher cost |
| Pumps |
|
Stand Alone Pump
Note: One pump required per dispenser
|
Single Function Pump
Skid |
Submerged pump in LNG
for instant start-up
Dedicated to dispensing
only
|
Maximum redundancy
for multiple dispensers
No cool down required
|
Single-purpose pump
Piping, etc. installed
on site rather than at factory
|
Multi-Function Pump
System
Note: This skid is used both for offloading and
dispensing |
Multi-Function Pump
Skid |
Submerged pump in LNG
Multi-function skid
controls for offloading, saturation and dispensing
|
No cool down required
Allows dispensing at
remote islands
Factory built for ease
of installation
|
Higher cost |
