Overfill protection for automatic day-tank filling
Generator fuel systems often transfer diesel or HVO
automatically from a bulk storage tank to a day tank
or generator belly tank. These filling cycles can take
place unattended, making the receiving tank’s overfill
protection an important equipment-selection decision.
DEADSTOP provides a mechanical layer of protection
alongside the system’s normal filling controls and
alarms. When fuel reaches the float’s activation level,
the valve closes completely to stop incoming flow.
No electrical supply or external control signal is
required to actuate the valve.
For generator fuel-system installers, tank manufacturers
and critical-power specifiers, it offers a
float-operated shut-off option for pressure-fed
tank-filling duties.
Why complete shut-off matters
Some overfill valves intended for supervised road-tanker
deliveries incorporate a deliberate leak path. After
activation, the driver stops delivery at the tanker,
then drains residual fuel from the delivery hose and
connecting pipework through the valve into the tank.
That drain-down function serves a different purpose
from complete shut-off. In an unattended bulk-to-day-tank
transfer system, a deliberate leak path can allow fuel
to continue entering the receiving tank while upstream
pressure remains.
DEADSTOP stops the flow completely.
Its zero-leak closure has no deliberate drain-down
path through the actuated valve, making this a key
distinction when selecting overfill protection for
automatic filling.
Features that support reliable fuel shut-off
-
Direct float operation:
responds to the fuel level in the receiving tank,
providing mechanical overfill protection should
the normal filling controls fail to stop delivery.
-
Zero-leak closure:
completely stops incoming fuel when the float
actuates the valve.
-
Pressure-assisted sealing:
the valve shuts in the direction of flow, with
fill pressure helping maintain the closed seal.
-
10–500 litres per minute:
accommodates a range of pressure-fed filling duties,
including low-flow transfer applications.
-
Maximum operating pressure of 10 bar:
provides a defined pressure limit against which
to check the transfer-system duty.
-
Cartridge construction:
allows installation and access for examination
through a single 2" tank opening, subject
to the specified mounting arrangement.
-
Factory tested:
every valve is tested before leaving the manufacturer.
Choose your float arrangement
Select the float version to suit the valve mounting
position and the tank’s required maximum fuel level.
Fixed float — DEAD-STOP
The standard float closes the valve when fuel reaches
approximately 145 mm below the bottom of the valve.
Choose this version where the standard activation
position provides the required shut-off level.
Adjustable float — DEAD-STOP-AF
A cut-to-length float extension allows a lower
activation position to suit the tank arrangement.
This provides flexibility where additional ullage
or a lower maximum fuel level is required.
Both listed valve versions include a 2" BSP locknut.
Check available float clearance and follow the
manufacturer’s instructions when determining the
adjustable tube length. Measurements below the valve
are not automatically measurements below tank brimfull.
Connect threaded inlet pipework
DEADSTOP has a 2" square-flange inlet.
Female BSPT adaptor kits connect this inlet to
threaded pipework in the following sizes.
Select the inlet adaptor separately from the tank
mounting components. Check the tank opening, mounting
dimensions and pipework arrangement against the
manufacturer’s installation instructions.
Integrating DEADSTOP into a generator fuel system
Complete valve closure causes pressure to rise in
the upstream pipework. The transfer pump, shutdown
controls and pressure-protection arrangement must
accommodate a closed delivery path within the
equipment’s operating limits.
The valve reopens only after upstream pressure has
dissipated and the fuel level has fallen. Account
for this behaviour when specifying the transfer
controls and restart sequence.
Install the valve upright, provide clearance for
unrestricted float movement and support connecting
pipework to avoid stressing the valve. Follow the
manufacturer’s installation and maintenance
instructions, and test correct operation before
putting the system into service.
Get help selecting your valve and accessories
PFS Fueltec supports generator fuel-system installers,
tank builders and specifiers with equipment supply
and practical product-selection guidance.
We can help identify the DEADSTOP float arrangement,
inlet adaptor and mounting accessories for your
requirement.
Send us your tank drawing, required shut-off level,
fuel type, transfer flow, delivery pressure and
pipework size.
Email our fuel equipment team
or call
01376 535260.