Technology of Displacer Type Liquid Level Switches
Displacer Type Liquid Level Switches are based upon simple buoyancy, whereby a spring is loaded with weighted displacers which are heavier than the liquid. Immersion of the displacers in the liquid results in buoyancy force change, which moves the spring upward. Since the spring moves only when the level moves on a displacer, spring movement is always a small fractionof the level travel between displacers. A magnetic sleeve is connected to the spring and operates within a non-magnetic barrier tube. Springmovement causes the magnetic sleeve to attract a pivoted magnet ƒ, actuating a switch mechanism ≈ located outside the barrier tube. Built-in limit stops prevent over stroking of the spring, under level surge conditions.
Features of Displacer Type Liquid Level Switches
- Narrow or wide level ranges achieved through multiple switch mechanism capability.
- Up to 4 set points and 3 switches.
- Displacers adjustable at any point along the suspension cable.
- 10 feet (3 meters) suspension cable standard.
- Anti-surge design eliminates the possibility of switch shortcycling.
- Flanged or threaded mounting available.
- Easy installation.
- Field adjustable set point and switch differential.
- NACE models.
- Floating rooftop models.
- Proof-er® ground check.
- Choice of displacers: Porcelain, 316 Stainless steel, Karbate, Brass.
- Choice of switch mechanisms: Dry contact,Pneumatic, Hermetically sealed.
- Available housings: NEMA 1, carbon steel for pneumatics; TYPE 4X/7/9, Class I, Div. 1, Groups C & D, polymer coated aluminum; TYPE 4X/7/9,Class I, Div. 1, Group B, polymer coated aluminum.
Applications of Displacer Type Liquid Level Switches
- Foaming or surging liquids
- Agitated fluids
- Sewage handling
- Dirty liquids
- Heavy oils
- Liquids with solids