Mercoid® displacer type level controls, ideal controlling industrial sump pumps.

Industrial sumps and other underground tanks are ideal applications for top mounted Mercoid® displacer type level controls. Easily installed, these controls use porcelain displacer type level controls. Easily installed, these controls use porcelain displacers that do not float on the surface of liquids but are suspended on a coil spring and cable. As the liquid in the tank reaches the level of the upper displacers their weight decreases by an amount equal to the liquid displaced allowing the spring to move the cable upward, actuation the switch and the pump is turned on . As the liquid level falls below the upper displacers they move only a small amount, staying within the switch deadband until the liquid level falls to the center of the bottom displacer. At this point the switch Is deactivated stopping the pump. The pump will remain deactivated until the water level rises to the upper displacers, repeating the cycle. The displacers are not affected by turbulence, pressure or chemicals and are excellent for tanks with viscous or dirty liquids. The level differential is easily adjusted by repositioning of the displacers on the 316SS cable.

Switches control water level and tank pressure.

A hydro-pneumatic tank with a deep well pump maintains desired pressure in a water system. The pump, however, delivers entrained air along with makeup water, requiring periodic tank venting to prevent excess pressure buildup. As both water level and tank pressure must be maintained, one side of the W. E. Anderson® Duotect® pressure switch is interlocked with the W.E. Anderson® L-4 float switch via the control box. When tank pressure falls below the preset system pressure due to water drawdown, the Duotect® switch starts the pump and transfers control to the float switch. When the preset water level is reach, the float switch turns pump off. If entrained air has increased the pressure beyond the limit set in the other side of the Duotect® pressure switch, after a time delay covering several normal cycles, the switch will open the solenoid valve and vent the tank down to proper pressure.

Proximity explosion proof Ultra-Mag™ dry level switches provide highly reliable powder and bulk solids level monitoring capability with either the suspended ("S") or flange ("F") mounted models.

A magnetic coupling completely seals the switch(es) in the housing from the product and environment, assuring high reliability and enhanced safety. Alarm capability is depicted above. Side-mounted flange models are applicable for all bin levels. Top-of-the-bin suspension mounted models for high and intermediate point level provide improved sensitivity (in materials with bulk densities as low as 5 pounds per cubic foot), and enhanced vertical adjustment capability compared to flange mounted models. Convenient external adjustment screws simplify field setup. Material problems associated with flange mounted models are solved by using suspended models. Elastomeric diaphragms are typically used in products such as tly ash, plastics, grain, powders, foundry sand, cement, aggregate, coal metal chips and glass. For pneumatic )pressure_ application, se of porous filter fabric diaphragms eliminates venting requirements due to inherent ability to breathe. Many different diaphragm materials are available to till the wide variety of needs in the industrial market.

Mercoid® model 123 level controls provide high and low alarm on large deaerator tank.

Liquid level in external piping equals level in tank. When level rises to high limit, float in upper model 123 is lifted, actuating switch to sound high level alarm. When level drops to low limit, lower model 123 sounds low level alarm.

Important Note
The control hook-ups and sketches, and other application information shown in this Bulletin are generalized and abbreviated to present the basic application idea only.

We believe this application information to be reliable, but it is intended for use by persons, at their own discretion, having technical skill and knowledge of the business. Neither Dwyer Instruments, Inc., nor the Mercoid, W. E. Anderson or Proximity Divisions, shall be liable for loss, damage, or expense directly or indirectly arising from the use of any products described herein. In no even shall any of these Companies be liable for direct, indirect, special, or consequential damages.