Rosemount 2120 is a reliable high level alarm switch for hydrocarbon storage tanks. It detects if the liquid level is high, and sends an alarm signal to shut any feed line valves or pumps to prevent tank overfilling and subsequent spillage.
The Rosemount Extended length 2120 is fitted to a nozzle at the tank roof, either directly or by use of an adjustable clamp gland. This tuning fork style switch is designed to vibrate the forks at their natural frequency. Should the liquid level rise to the high level height, the forks become immersed in the liquid and the frequency of vibration changes. The built-in control electronics detects this change and indicates an alarm condition by switching the output.
Rosemount 2120 can be set to switch either if the forks get wet or dry, and both Explosionproof, and SIL2 I.S. models are available.
Technical Data
Principle:
Fast-drip-off vibrating fork.
Fork Length:
2 in. (50 mm) to 118 in. (3 m).
Special Features:
Mode switch: Rosemount 2120 can be set to switch if the forks get either wet (typically high alarm) or dry (typically low alarm).
Adjustable time delay: The time delay is selectable (0.3, 1, 3, 10 or 30 s from dry to wet / wet to dry).
Heartbeat LED: The status indicating LED gives constant indication of whether or not the Rosemount 2120 is functioning correctly. The LED is split when the switch is on and it flashes if it is off.
Magnetic Test point: The test point, located on the side of the housing, can be used for alarm simulation.
Housing Material:
Plastic, Aluminum alloy, or 316 SST (stainless steel).
Conduit Entry:
Two cable / conduit entries, M20, 1/2-in. or 3/4-in. NPT.
Terminal Connection:
Wire diameter max. 0.1 in2 (2.5 mm2). National regulations.
Protection:
Rosemount 2120 is polarity insensitive and has over-current, short-circuit and load-missing protection.
Ingress protection: IP 66/67 or Type 4X.
Surge protection according to IEC61326.
Process Connection:
Threaded:
3/4-in. BSP or NPT
1-in. BSP or NPT
Flanges:
ANSI, 1.5-4 in. 150-600 lb
DIN (EN), DN 40-100, PN 10/16-100
Wetted Material:
316L SST (EN 1.4404) or Hastelloy C.
Maximum Process Pressure:
-3.62 psig (-0.25 barg) to 1450 psig (100 barg), depending on the process temperature. Note: If the Rosemount 2120 switch is used with a clamp gland, max. operating pressure is limited to 18.85 psig (1.3 barg).
Maximum Process Temperature:
-140 to 302 °F ( -140 to 150 °C), depending on the ambient temperature.
Liquid Density Range:
Minimum 37.5 lb/ft3 (600 kg/m3).
Liquid Viscosity Range:
0.2 to 10,000 cP (centiPose).
Hysteresis (water):
± 0.039 in. (± 1mm) nom.
Switching Point (water):
0.5 in. (13 mm) from tip (vertical) / from edge (horizontal) of fork (this will vary with different liquid densities).
Certification:
FM Explosion Proof Approval
FM IS Approval
CSA Explosion Proof Approval
CSA IS Approval
CSA Non-Incendive Approval
ATEX Flameproof Approval
ATEX IS Approval
Electro Magnetic Compatibility (EMC) Directive: EN61326 Emissions to Class B.
Vibration Resistance: EN60721 level 3M6/4M6.
Overfill Protection: Approved by DIBt/WHG.
SIL Declaration of Conformity: SIL 2, IEC 61508 (Type B).