The Square D 9037HG31 Float Switch is a level switch used to control the liquid level within a closed tank. The float assembly is installed in a horizontal (side mount) position and includes a 2.5” NPTscrew-in bushing. This assembly includes the electrical switch as well as the float and float rod. The electrical contacts include 2 snap action switches that are rated for power circuits. The switch contacts are field reversible and can be set to close on either liquid rise or liquid fall. This model utilizes a 90° offset float rod and can control a 6.00” minimum to 11.50” maximum water level change. Within boiler feed systems, the 9037HG31 is typically used for one of two applications: makeup water control for a boiler feed tank, or pump control for a condensate tank. When used on a boiler feed tank, the 9037HG31 is commonly paired with an electronic two position makeup valve for ON/OFF operation to fill the tank. When the float is in the down position, the contacts will close and energize the makeup valve. When the float reaches the up position, the contacts will open and de-energize the makeup valve. The dead band between open and close can be adjusted within the maximum and minimum control range. This type of control is common for applications where maintaining a steady flow into the tanks is not required. This type of control is typical for small atmospheric feed tanks (less than 500 gallons). When used on condensate tanks, the 9037HG31 is commonly paired with a transfer pump for ON/OFF operation to empty the tank. When the float is in the up position, the contacts will close and energize the transfer pump. When the float reaches the down position, the contacts will open and de-energize the transfer pump. Note: Due to the 90° offset rod, this assembly will not fit through a 2” full coupling. This assembly will only fit through a 2” threaded tank flange or equivalent. If the tank connection utilizes a full coupling please select a model with a 45° rod.

• Mounts directly to tank via 2.5” NPT bushing (will not fit through 2” full coupling due to 90° rod)
• Two (2) sets of contacts (DPST switch)
• Reversible contacts. Close on liquid rise OR liquid fall (close on liquid fall is default)
• Adjustable 6.00” to 11.50” float control range
• Float position indicated through external pointer
• NEMA 1 electrical junction with three (3) ½” knock-outs
• Motor Horsepower Rating:o 2 hp @ 115 VAC 1 phase o 3 hp @ 230 VAC 1 phase
For use on tanks up to 50 psi For use in ambient temperatures up to 220°F For use with liquid temperatures up to 215°F 304 SS float, 316 SS float rod, cast iron bushing, brass connector, and Buna-N packing 90° Rod Offset The float is located on the right side of the assembly when viewed facing the indicator pointer. Designed for a minimum cyclelife of 1,000,000 mechanical cycles and 100,000 electrical cycles. Actual cycle life will vary with cycle rate and current.