Download
the Series 700 Detailed Datasheet in Acrobat Format
Insertion: 14
inches 
The
Delta Controls Model 735 design provides significant
advantages over the older Model 740 design. The 735 is smaller, easily handles
high pressures and temperatures, and is immune to most heavy vibrations. It
is also extremely reliable.
The Delta Controls Model 735 provides switch action as the liquid moves past a fixed point on the side of the vessel or tank. The float is inserted into the vessel through a flanged or threaded connection. The vessel connection must be located at the elevation where switch action is to occur; the position is relatively fixed and little adjustment is possible.
This type level switch uses a counterbalance principal, which allows the use of smaller, heavy wall floats. The use of these heavy-duty floats significantly improves the safety and reliability of the switch. The purpose of the counterweight is to offset the extra weight of the heavy-duty float. This results in the element only having to provide enough floatation to operate the switch magnet. In addition, the element is smaller, which allows the use of less expensive and smaller process connections.
A counterbalanced float is held in a horizontal position by a pivot mechanism. As the liquid level rises, the float moved upwards. This movement results in a rotary motion of the drive magnet, which carries it into the field of the switch station magnet. The switch station magnet is driven against the outside of the sealing tube and the output switch is actuated.
Similarly, as the liquid level falls,
the sensing element moves downward. The drive magnet is rotated back through
the field of the switch station magnet. The switch station magnet is operated,
returns to its original position, and the output is deactuated. This dual opposed
magnet design provides snap action, immunity from vibration, and greatly improves
reliability.