SIMPLEX DAY TANK DUPLEX PUMP OPTIONS SDE = Economy Day Tank, SST = Super Day Tank, SMT = Manual Day Tank A = Available, NA = Not Available, S = Standard Other Day Tank Options: Mechanical, Containment/Rupture Basins, Control Devices and Alarms, Gravity Fed, Sight Glasses, Level Indicators and Gauges, Pumps and Motors
Duplex pump options are used to increase the reliability of a day tank system through the addition of a second, backup pump and level control. In a duplex system, one pump is designated the “lead” pump and the other is the “lag” pump. The lead pump automatically refills the day tank over the tank’s normal operating range of 50% to full. Normally, once the tank has been initially filled, the fuel level should never drop below 50%. Less than 50% is indicative of either a failure of the lead pump or consumption in excess of pump capacity. The lag pump and its separate level controller, acting as a backup senses a drop in fuel level below 50% and starts the lag pump, which then continues to run, along with the lead pump, until the tank is full. When ordering, remember that duplex systems include two motor-pumps and therefore require a quantity of two of any option related to the motor or pump, such as solenoid valves, strainers, etc.
NO.	SDE	SST	SMT	DESCRIPTION
345	NA	A	NA	Multifunction duplex pump controller system providing selectable operating modes, including: 1) Automatic lead pump alternating with automatic lag pump backup 2) Automatic alternating, automatic lag pump backup 3) Automatic twin pump operation (both pumps run simultaneously) automatic level control backup 4) Manual operation Basic System includes the following: 1) All SST controller features 2) Mode selector switch 3) Pump running indicators for each pump 4) Two 1/3 HP, 120V, 2 GPM pumps, with check valves
346	NA	A	NA	Running time meter, one for each pump. (Order two for option 345: Duplex Pump Systems.)
347	NA	A	NA	Manual duplex pump selector switch. Used to select one of two pumps or both pumps for automatic operation. In single pump mode, off-line pump not available for automatic operation. Includes: 1) Selector switch with positions “pump-1,” “pump-2,” “both” 2) Pump running lights 3) Two 1/3 HP, 120V, 2 GPM pumps, with check valves

Other Day Tank Options: Mechanical, Containment/Rupture Basins, Control Devices and Alarms, Gravity Fed, Sight Glasses, Level Indicators and Gauges, Pumps and Motors Back to Economy Day Tank (SDE) Page. Back to Super and Manual Day Tanks (SST and SMT) Page. Back to top of page. Request Quote.

Simplex, Inc., 1139 North MacArthur Boulevard, Springfield, IL 62702-2314 800-637-8603, 217-525-6995 (24 Hr.), Fax 217-525-7984