The DLS Switches are mounted on a side of vessels, even if very narrow. The liquid level is checked by a float integral with a small and very flexible tube; within this tube there is a rod fixed on only an end : the lift coming from float causes a bending on the outer tube and consequently a side thrust on the inner rod, that makes the output device trip (trip on rise); then, when the level comes down again and exceeds the preset point, the float makes the output device come back to the initial point (reset on fall); between the set and the reset points there is always a small gap, named differential, of about 5-10mm. The trip happens when level reaches about the median line of the float. The inverse function is available too : Trip on fall and Reset on rise. The output can be electric or pneumatic, is snap action and is placed in the housing.

A so small differential can be obtained thanks to the combination between volume and weight of float, and length of the arm supporting the float; for this reason many types of float are available, different both in materials and in volumes, in stainless steel AISI 316 or in Plexiglas (polymethacrylat), in polyethylene, etc; everything depends on the kind of liquids, on their temperature,

pressure, corrosiveness and specific gravity. Since it is frankly impossible to list all the existing solutions for every applications, Domizi Snc reserve to propose the properest

solution only after having known the actual operating conditions of the Level Switch.

Outer finish : Switches in carbon steel have the standard painting so realized : first coat in epoxy resin, and outer coat in green polyurethane resin; suitable for corrosive marine environments and tropical climates. Switches in stainless steel are polished and left bare.
 

The Level Switches meet the ATEX standard.
 

APPLICATIONS. Level control on vessels containing various types of industrial liquids, in off-shore and in-shore oil plants.

The Switch can operate with liquids having pressures up to 500 Bar, temp. up to 120°C and specific gravity from 500kg/m³ up.
 

Connection to vessel. By threaded body NPT-M, or by flange ANSI 150÷2500 psi.
 

Housing. In aluminium casting, in electric or pneumatic version.

• With 1 microswitch SPDT : page 25. Size : Ø155×200mm, flame-proof EEx dc IIC T6; with 1 hole for electric connection : ¾ ” NPT-F (or ½” NPT-F).

• With 1 pneumatic valve On-Off-Vent : page 25. Size 180×180×100mm, water-proof; with 2 manometers Ø40mm; with 3 holes for pneumatic connection : ¼” NPT-F for inlet, outlet and vent air tube.
 

Housing-holder. In carbon steel, in stainless steel AISI 304 or AISI 316. Height : ~75mm (in any case, even in the version with fins for high temperatures, +181/+300°C, or without fins for low temperatures, –21/–60°C).
 

Upon request, special versions can be produced too.