![background image](http://html1.mh-extra.com/html/gasboy/atlas/atlas_owners-manual_3685456047.webp)
MDE-4363G Atlas™ Fuel Systems Owner’s Manual · August 2018
Page 3-37
Shear Valve
The Atlas Fuel System
Shear valves, required by NFPA 30A, are intended to shut-off the flow of fuel at the dispenser
base (hydraulics area) during vehicle impact or fires. A single-poppet shear valve prevents the
fuel flowing from the underground tank. A double-poppet shear valve prevents fuel flowing
from the underground tank and the dispenser. In an event that the product fails to exit the
dispenser/pump hose, ensure that the shear valve is not closed.
A shear valve in the open position is shown in
Note: The shear valve is located inside the dispenser on the lower cross brace in the pit box
area.
Figure 3-22: Open Position of Shear Valve
CAUTION
WARNING
Applicable to Dispensers Rated for E85 Use:
Do not use tape at the very end of the pipe nipple to avoid tape entering the dispenser hydraulics.
Tape in the hydraulics can cause failures of valves, nozzles, or other significant problems.
Use only UL-listed TPS PTFE Pipe Sealant manufactured by SAF-T-LOC International Corp.
Use only UL-listed Taega Technologies Inc. Teflon tape.
Note: Teflon tape must be used only at the inlet pipe connection.
S0000349
Shear Valve
Lower Cross Brace
Shear Valve in
Open Position
Shear Valves may stick parochially in the open position causing fuel to flow through a
shear valve thought to be closed. Always test for proper closing by attempting to dispense
fuel into an approved container. Fuel must not continue to flow after pressure has been
relieved.
WARNING