Model 765D

SKU: 765D

Vertically Rising Float, One On/Off Differential Point

  • Operation: A float with a long stroke action moves up and down as the liquid level varies. Switching occurs at up to four separate points.
  • Switching Stations: 1 to 4; alarm and/or differential
  • Differential: up to 72″
  • Specific Gravity: 0.4 to 2.4
  • Temperature: -20 to 750°F
  • Pressure: -15 to 2200 PSIG
  • Process Connection: Same as type 760

Operation

The Delta Controls Model 765D provides switching at two elevations of a varying liquid level. The unit has its float mounted outside the process vessel in a cage. The external cage design is utilized to minimize process turbulence effects and in order that the level control may be valved off from the process vessel and depressurized for maintenance without disturbing the operation of the process. The output of the control consists of and on/off switching action as the liquid level varies. The differential level change required to change the output switch from one condition to the other may be increased up to about 2 inches.

The barrier tube isolates the process liquid from the switch station. The switch station is on the outside of the barrier tube. It is equipped with a magnet whose lines of force pass through the nonmagnetic barrier tube. The magnet is pulled in against the outside of the tube when the attractor is lifted into the magnetic field inside the tube.

Installation

The Delta Controls Model 765D should be mounted vertically near the process vessel containing the liquid level to be monitored. Long lines connecting the process vessel to the element chamber should be avoided; but when necessary, they should be sloped 1" per foot towards the process vessel to limit sedimentation buildup.

Adjustable Differential Action

The liquid level rises and the float lifts the attractor in front of the switch station magnet. The magnet pulls in, the output switch is actuated, and the attractor is "captured" and held in place.

Decreasing liquid level moves the float/rod/collars downward. The output switch remains actuated until the top collar moves down against the attractor and pulls it out of the magnetic field. The attractor then falls down against the lower collar by gravity and the output switch is deactuated.

The spacing between the top collar, at its maximum elevation, and the attractor determines the amount of liquid level differential between output switch actuation and deactuation. Lowering the top collar decreases differential. Access to the collars is achieved by depressurizing the unit and removing the barrier tube.

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