OPW 61fSTOP Overfill Prevention Valves
The OPW 61ƒSTOP Overfill-Prevention
Valve is designed to prevent overfilling of
aboveground storage tanks by providing
a positive shut-off during a pressurized fill (pump-on fill) delivery. It threads
into the fill opening and is an integral
part of the fill tube. The 61ƒSTOP is fully
adjustable to allow for easy installation
in new or existing aboveground tanks of
various heights and storage capacities.
The 61ƒSTOP is a single-action, complete
shut-off valve. When the liquid-level rises
to your specific, pre-determined tank
capacity, the valve mechanism is released
and automatically closes with the flow
of the product. Any excess product left
between the valve and the fuel-delivery
coupler is drained into the tank through
internal drain vents. The drain vents on
the 61ƒSTOP act as an anti-siphon, by
introducing air/vapor into the fill line,
to help isolate the tank from a potential
siphon due to a broken or leaking
fill-pipe.
The 61ƒSTOP, available in either 2" or 3"
full-flow models, maximizes flow rates
and minimizes delivery times. The 2"
61ƒSTOP requires a 4" tank opening and
minimum tank ullage (space from the top
of the stored product to the inside top
of the tank) of 8" on the 61ƒSTOP-1000
Cylindrical Float model and a minimum
ullage of 4" on the 61ƒSTOP-2000 Float
Arm model. The 61ƒSTOP-1000, with the
cylindrical float, eliminates the need to
position the valve to avoid tank walls or
cross-bracing. The 61ƒSTOP-2000 with
the float arm allows for increased usable
storage capacity in the tank, and is well suited for small-capacity rectangular
ASTs. The 3" 61ƒSTOP requires a 6" tank
opening and incorporates a cylindrical
float requiring 8" of tank ullage space