THERMAL DIFFERENTIAL LEVEL & FLOW SWITCHES

KENCO's Thermal Differential Switches are designed for a wide range of flow and level applications. These switches can be used to direct either the overall liguid level or a liquid-liquid interface. They can also be used to detect a specific flow rate or flow/no flow condition in liquids and gasses.

PRINCIPAL OF OPERATION:

The sensor consists of (2) Resistance Temperature Detectors (RTD's). One RTD measures the temperature of the fluid around the sensor. The other RTD is self-heated. This provides a temperature differential between the the two RTD's.

In a level application, the thermal conductivity of the liquid level is higher than the gaseous layer above the liquid. When the RTD's make contact with the liquid, there is a cooling effect with the liquid absorbing the heat from the heated RTD. This reduces the temperature differential increases, causing the relay to reset. This will also work in a liquid-liquid interface when the two liquids have different thermal conductivity (ex. oil and water).

In a flow application, there is a temperature differential during a no-flow or low-flow condition (the actual setpoint is adjusted during the calibration procedure). As the flow rate increases, the temperature between the RTD's decreases, causing the relay to change state. When the flow rate decreases, the temperature differential increases, causing the relay to reset.

FEATURES:

• Level And Interface Detection
• Flow Detection For Liquids and Gasses
• Fast Response Time
• No Moving Parts
• Temperature Compensation

BENEFITS OF OWNERSHIP:

• Application Flexibility
• Better Process Control
• Reliability
• Stability And Repeatability

APPLICATIONS:

• Level Detection
• Nitrogen Flow Detection
• Low Flow Monitoring
• Liquid-Liquid Interface Detection
• Foam-Liquid Interface Detection
• Pump Protection
• Flare Systems

INDUSTRIES:

• Chemical
• Petroleum
• Water/Wastewater
• Pharmaceutical
• Pulp & Paper
• Power
• Aerospace

SPECIFICATIONS

MODELS:
KTDL = Level Switch
KTDF = Flow Switch

PROCESS CONNECTIONS:
050 = ½" NPT
075 = ¾" NPT
100 = 1" NPT
3A1 = 1½" Sanitary
RA1 = 1" 150# ANSI Flange
RA2  = 2" 150# ANSI Flange
RB1 = 1" 300# ANSI Flange
RB2 = 2" 300# ANSI Flange
LFS  = Low Flow Sensor
SPL = Special Connection

SENSOR MATERIALS:
S6 = 316L SS
S4 = 304 SS
SL = 304L
HB = Hastelloy-B
HC = Hastelloy-C
IO = Inconel 600
MN = Monel
A2 = Alloy-20
SM = Special Material

INSERTION LENGTH (Inches):
002.00 (standard)
002.50 - 120.00 (optional)

INPUT POWER:
110 = 110Vac
220 = 220Vac
24D = 24Vdc
24A = 24Vac

CONFIGURATION:
LE = Integral Mounting
RE = Remote Mounting

ADDITIONAL OPTIONS:
00 = No Options
RT = RTD Output
LT = Live Tap
CE = CE Approved
EN = Extended Neck
HT = *High Temp (850°F)
MT = *Medium Temp (572°F)
XW = Explosion-proof Window
CA = Additional Cable
VI = Variable Insertion
CB = Factory Calibration
TO = Thermocouple Output
TG = SS Tag
TE = Sensor Installed in Tee

POWER SUPPLY:
AC = 110Vac or 220Vac @ 50/60 Hz
DC = 24Vdc
OUTPUT:
Relay = 5A DPDT - Failsafe is field selectable
TEMPERATURE RANGE (Electronics):
 -40°F to 140°F (-40°C to 60°C)
TEMPERATURE RANGE (Sensor):
Standard = -100°F to 390°F (-70°C to 200°C)
Medium Temp. = -100°F to 572°F (-40°C to 300°C)
High Temp. = -100°F to 850°F (-40°C to 458°C)
PRESSURE RANGE:
Atmosphere to 3000psi
OPERATING RANGE (Flow):
Aqueous Liquids = 0.01 to 2.5 feet/second
Hydrocarbon Liquids = 0.01 to 5.0 feet/second
Gasses = 0.1 to 500 feet/second
RESPONSE TIME: 
 0.5 to 5.0 seconds (media dependent)
STABILITY:
<0.5% from caliberated setpoint over a range of ±50°F
REPEATIBILITY:
±1.0%