FFS-0772 Forecourt Guide No 6 InteractiveSpreads - Flipbook - Page 12
DEFENDER SERIES® OVERFILL PREVENTION VALVE:
DROP TUBE LENGTHS
DEFENDER SPILL CONTAINMENT (REF.)
TOP OF RISER
“X”
• Distance from the seat surface of the upper drop tube to the bottom of the underground storage tank. The seat
surface will vary depending on the type of installation (see Figure 2).
B
• 95% tank volume - obtained from the tank chart provided by the tank manufacturer. To find the 95% tank level on the tank
chart, multiply the actual tank capacity by 95. Then find on the tank chart the level measurement that matches the
calculated volume the closest.
Note: If local codes allow the positive shut-off level to be different from 95%, the installing contractor may adjust the
“B” dimension per the tank chart to achieve the desired level.
TOP OF TANK
“X”
UPPER DROP TUBE
A
Note: If tank tilt is an issue, the installing contractor may use best judgement to adjust “B” dimension accordingly, so
none of the fittings located on top of the tank are exposed to product due to overfilling. per EPA 40CFR280.
95% TANK VOLUME
Undermesh Fill Adapter
(EBW® Legacy Series)
Undermesh Bucket
(PhiI-Tite™ Series)
Inside Bucket
(Defender Series®)
OVERFILL PREVENTION VALVE
“A”
(U.S.T)
A
LOWER DROP TUBE
“B”
A
“Y”
A
A
“Y”
MARKING & CUTTING THE TUBES
1. Mark the upper drop tube with the length “X”
calculated from Figure 1, measuring per Figure 3.
2. Mark the lower drop tube with the
length “Y” calculated from Figure 1.
Upper Drop Tubes
Lower Drop Tube
6” (152 MM) MAX*
BOTTOM OF TANK
TO FIND UPPER DROP TUBE LENGTH "X"
GALLONS
TOP OF RISER TO
BOTTOM OF TANK
"A"
-
X
(SUBTRACT)
GALLONS
(95% TANK VOLUME)
(SUBTRACT)
2.5" (63.6 MM)
=
X
Poppeted Coaxial (EBW)
Measure from retaining ring.
95% VOLUME
HEIGHT
"B"
-
(SUBTRACT)
-
(SUBTRACT)
15.75" (400 MM)
POSITION AND
MOUNTING ADJUSTMENT
(EQUALS)
OPV LENGTH
OFFSET
X
TANK BOTTOME
CLEARANCE
=
Non-Poppeted Coaxial (EBW)
Measure from retaining lug.
(EQUALS)
95% VOLUME HEIGHT
=B
"X"
Y
TO FIND LOWER DROP TUBE LENGTH "Y"
95% VOLUME
HEIGHT
"B"
.95
=
Cut Straight
Dual Point
Measure from flange.
* IF LOCAL CODES REQUIRE THIS DISTANCE TO
BE SMALL, SUBTRACT LESS THAN 6" (152 MM)
TO FIND 95% TANK VOLUME AND
MEASUREMENT FROM TANK CHART
ACTUAL TANK CAPACITY
NOT TO SCALE
"X"
UPPER DROP TANK LENGTH
LOWER DROP TANK LENGTH
X
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