A displacer-type level transmitter LP Series

The LP series from Tecfluid is a displacer-type level transmitter with local indication for continuous measurement of liquid levels (and interface) in tanks and vessels under demanding industrial conditions (high pressure, temperature, aggressive media). Designed for top-mounted installation on tanks.

Key parameters:

• Measuring range: 0.3…6 m

• Minimum density difference (for interface): 0.1 kg/l

• Liquid density: 0.6…2 kg/l

• Accuracy: ±5 mm

Principle of Operation

The level transmitter operates according to Archimedes’ principle. A displacer of constant volume and weight is suspended from a measuring spring and is always fully immersed in the liquid. As the liquid level changes, the buoyant force changes, thereby altering the effective weight of the displacer. This causes extension or compression of the spring. The spring movement is transmitted via a magnetic coupling to the local indicator pointer and/or to electrical sensors (reed switches, inductive contacts, or 4–20 mA transmitter).

Features

• Measuring range: 300 mm – 6 m

• Accuracy: ±5 mm (standard)

• Displacer and wetted parts materials: stainless steel 316L, Hastelloy C, titanium, PVC, PP, PVDF

• Process pressure: standard PN40, higher ratings on request

• Process temperature: -60…+150 °C (standard), up to +400 °C with heat separator, down to -120 °C for cryogenic versions

• Process connections: flanged DN40–DN100 (EN 1092-1, ANSI), threaded G/NPT 1"–2"

• Indicator housing: aluminium (IP65), stainless steel (IP67), plastic PP (IP65)

• Local indication: circular scale 150–200 mm diameter, in % or length units

• Electrical outputs: 1–2 adjustable reed or inductive contacts, optional 4–20 mA transmitter + HART/MODBUS

• Hazardous area approvals: ATEX/IECEx Ex ia / Ex d

• Additional options: heating jacket, insulation, custom scales, interface measurement capability

Main Application Areas

• Chemical and petrochemical industry (aggressive liquids, acids, alkalis)

• Oil & gas refining and storage (tanks, separators)

• Power generation (boiler houses, condensate tanks)

• Food and pharmaceutical industry (hygienic versions)

• Water and wastewater treatment

• Any processes requiring reliable local level indication under high pressure/temperature or corrosive conditions