24
Appendix C (continued)
71SO Overfill Valve in Tank Complete Shut Off Level Worksheet
Important: This is meant to be supplemental worksheet and not a substitute to following the installation
manual instructions. All length measurements are in inches. Please contact the Authority Having Jurisdic-
tion (AHJ) and review local, state, and national codes to determine the regulatory requirements governing
shut-off capacity in your region, as well as take into account other considerations such as extreme tank tilt.
Take the following measurements with the valve in-
stalled in the tank:
Distance from the 71SO inlet tube flange to the cast
lug in the 71SO body (see figures), upper tube length.
Note:
the Upper Tube Length must be at least 16” to in-
clude the protective bend in the tube.
(D) = ______________________
Distance from the 71SO inlet tube flange to the top and
bottom of lower tube, valve length.
(W) = _____________
(U) = _____________
Distance from the 71SO inlet tube flange to the bottom
of the tank. Note: If a tank bottom protector is present it
may be necessary to add this thickness to dimension
(OPW 6111 & 61TP models add 0.6”)
(B) = _____________
From the tank calibration chart provided by tank manu-
facturer find the dipstick number (Y) which corresponds
to the 100% volume.
(Y) = _____________
1. To determine complete shut-off percentage:
Subtract upper tube length (D) from distance to tank
bottom (B)
(X) = (B) – (D) + 1.5” =________________________
Using the tank calibration chart provided by the tank
manufacturer determine the tank capacity at the cal-
culated (X) dimension and the 100% volume (Y) tank
capacity.
(X) tank capacity in gallons
= _______________
(Y) tank capacity in gallons
= _______________
Complete SO% = (X) capacity / (Y) capacity x100
=
__________
Note:
The overfill valve must be installed per AHJ re-
quirements and all applicable local, state, and national
codes. If the overfill valve is set above the allowable
shut-off percentage the overfill valve must be removed
and replaced.
(B)
To Tank
(D)
Upper
Tube
(W) Valve
Length,
bottom
of cut
(Y)
Tank
Chart
100%
Volume
Dipstick
(U) Valve
Length,
top of
Note: This Appendix only applies to valves installed per Appendix C. See Appendix B for the standard valve
installation tank shut off level worksheet.
