1. INTRODUCTION
©2014 Kraus Global Ltd.
Retail CNG Dispenser Manual
5
1.7.2 Buffer storage systems
A buffer storage system comprises a large storage bank with a single
supply line to the dispenser, which is controlled by one KAF 402™
solenoid valve to start and stop gas flow.
After the target-fill-pressure is calculated, the solenoid valve remains
open for fuel delivery until the target-fill-pressure or minimum flow
setting is reached.
1.7.3 Cascade storage systems
Cascade storage systems typically consist of three separate storage
banks—a low, mid, and high bank. The low bank holds
approximately 70% of the total volume of storage, while the mid and
high banks hold 20% and 10% respectively.
Upon authorization, the MICON
®
will open all three banks for 4
seconds to ensure there is sufficient gas flow to continue with the fill.
The banks will then close for another 4 seconds for the target-fill
calculation. Once the target-fill-pressure is calculated, the low-bank
will reopen and deliver fuel until the flow rate drops to a
predetermined level—set in the MICON
®
. When this level is reached,
the mid-bank solenoid valve will reopen to deliver the fuel. If more
pressure is needed, the same sequence will occur to access the high-
bank until the target-fill-pressure or minimum flow setting is
reached.
